patch 8.1.0105: all tab stops are the same

Problem:    All tab stops are the same.
Solution:   Add the variable tabstop feature. (Christian Brabandt,
            closes #2711)

31 files changed, 1751 insertions, 174 deletions

diff --git a/runtime/doc/change.txt b/runtime/doc/change.txt
index 05c18e64d..b59f28f47 100644
--- a/runtime/doc/change.txt
+++ b/runtime/doc/change.txt
@@ -987,6 +987,11 @@ This replaces each 'E' character with a euro sign.  Read more in |<Char->|.
 			this (that's a good habit anyway).
 			`:retab!` may also change a sequence of spaces by
 			<Tab> characters, which can mess up a printf().
+			If the |+vartabs| feature is enabled then a list of
+			tab widths separated by commas may be used in place of
+			a single tabstop.  Each value in the list represents
+			the width of one tabstop, except the final value which
+			applies to all following tabstops.
 			{not in Vi}
 
 							*retab-example*
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index d37fa641a..65a9d17ea 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -7172,6 +7172,10 @@ A jump table for the options with a short description can be found at |Q_op|.
 	set.
 	NOTE: This option is set to 0 when 'compatible' is set.
 
+	If Vim is compiled with the |+vartabs| feature then the value of
+	'softtabstop' will be ignored if |'varsofttabstop'| is set to
+	anything other than an empty string.
+
 						*'spell'* *'nospell'*
 'spell'			boolean	(default off)
 			local to window
@@ -7723,6 +7727,10 @@ A jump table for the options with a short description can be found at |Q_op|.
 	   though.  Otherwise aligned comments will be wrong when 'tabstop' is
 	   changed.
 
+	If Vim is compiled with the |+vartabs| feature then the value of
+	'tabstop' will be ignored if |'vartabstop'| is set to anything other
+	than an empty string.
+
 			*'tagbsearch'* *'tbs'* *'notagbsearch'* *'notbs'*
 'tagbsearch' 'tbs'	boolean	(default on)
 			global
@@ -8468,6 +8476,44 @@ A jump table for the options with a short description can be found at |Q_op|.
 	written to disk (see |crash-recovery|).  Also used for the
 	|CursorHold| autocommand event.
 
+					*'varsofttabstop'* *'vsts'*
+'varsofttabstop' 'vsts'	string	(default "")
+			local to buffer
+			{only available when compiled with the |+vartabs|
+			feature}
+			{not in Vi}
+	A list of the number of spaces that a <Tab> counts for while editing,
+	such as inserting a <Tab> or using <BS>.  It "feels" like variable-
+	width <Tab>s are being inserted, while in fact a mixture of spaces
+	and <Tab>s is used.  Tab widths are separated with commas, with the
+	final value applying to all subsequent tabs.
+
+	For example, when editing assembly language files where statements
+	start in the 8th column and comments in the 40th, it may be useful
+	to use the following: >
+		:set varsofttabstop=8,32,8
+<	This will set soft tabstops at the 8th and 40th columns, and at every
+	8th column thereafter.
+
+	Note that the value of |'softtabstop'| will be ignored while
+	'varsofttabstop' is set.
+
+						*'vartabstop'* *'vts'*
+'vartabstop' 'vts'	string	(default "")
+			local to buffer
+			{only available when compiled with the |+vartabs|
+			feature}
+			{not in Vi}
+	A list of the number of spaces that a <Tab> in the file counts for,
+	separated by commas.  Each value corresponds to one tab, with the
+	final value applying to all subsequent tabs. For example: >
+		:set vartabstop=4,20,10,8
+<	This will make the first tab 4 spaces wide, the second 20 spaces,
+	the third 10 spaces, and all following tabs 8 spaces.
+
+	Note that the value of |'tabstop'| will be ignored while 'vartabstop'
+	is set.
+
 						*'verbose'* *'vbs'*
 'verbose' 'vbs'		number	(default 0)
 			global
diff --git a/runtime/doc/various.txt b/runtime/doc/various.txt
index 7c8f3111c..bd2b35ed7 100644
--- a/runtime/doc/various.txt
+++ b/runtime/doc/various.txt
@@ -453,6 +453,7 @@ N  *+timers*		the |timer_start()| function
 N  *+title*		Setting the window 'title' and 'icon'
 N  *+toolbar*		|gui-toolbar|
 N  *+user_commands*	User-defined commands. |user-commands|
+B  *+vartabs*		Variable-width tabstops. |'vartabstop'|
 N  *+viminfo*		|'viminfo'|
    *+vertsplit*		Vertically split windows |:vsplit|; Always enabled
 			since 8.0.1118.
diff --git a/runtime/optwin.vim b/runtime/optwin.vim
index cd1bea0cb..5ab5792ae 100644
--- a/runtime/optwin.vim
+++ b/runtime/optwin.vim
@@ -856,6 +856,14 @@ call <SID>OptionL("ts")
 call append("$", "shiftwidth\tnumber of spaces used for each step of (auto)indent")
 call append("$", "\t(local to buffer)")
 call <SID>OptionL("sw")
+if has("vartabs")
+  call append("$", "vartabstop\tlist of number of spaces a tab counts for")
+  call append("$", "\t(local to buffer)")
+  call <SID>OptionL("vts")
+  call append("$", "varsofttabstop\tlist of number of spaces a soft tabsstop counts for")
+  call append("$", "\t(local to buffer)")
+  call <SID>OptionL("vsts")
+endif
 call append("$", "smarttab\ta <Tab> in an indent inserts 'shiftwidth' spaces")
 call <SID>BinOptionG("sta", &sta)
 call append("$", "softtabstop\tif non-zero, number of spaces to insert for a <Tab>")
diff --git a/src/Makefile b/src/Makefile
index ca972547f..e9a15a0cf 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -2305,6 +2305,7 @@ test_arglist \
 	test_usercommands \
 	test_utf8 \
 	test_utf8_comparisons \
+	test_vartabs \
 	test_viminfo \
 	test_vimscript \
 	test_virtualedit \
diff --git a/src/beval.c b/src/beval.c
index 4ceddca19..74750a27d 100644
--- a/src/beval.c
+++ b/src/beval.c
@@ -124,6 +124,11 @@ get_beval_info(
 		*lnump = lnum;
 		*textp = lbuf;
 		*colp = col;
+#ifdef FEAT_VARTABS
+		if (beval->vts)
+		    vim_free(beval->vts);
+		beval->vts = tabstop_copy(wp->w_buffer->b_p_vts_array);
+#endif
 		beval->ts = wp->w_buffer->b_p_ts;
 		return OK;
 	    }
diff --git a/src/beval.h b/src/beval.h
index f4d1d80e9..49ba05b2e 100644
--- a/src/beval.h
+++ b/src/beval.h
@@ -71,7 +71,10 @@ typedef struct BalloonEvalStruct
     void		*clientData;	/* For callback */
 #endif
 
-    int			ts;		/* tabstop setting for this buffer */
+    int			ts;		// tabstop setting for this buffer
+#ifdef FEAT_VARTABS
+    int			*vts;		// vartabstop setting for this buffer
+#endif
     char_u		*msg;
 } BalloonEval;
 
diff --git a/src/buffer.c b/src/buffer.c
index 254aad461..1f1833fc7 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -271,7 +271,7 @@ open_buffer(
     /*
      * Set/reset the Changed flag first, autocmds may change the buffer.
      * Apply the automatic commands, before processing the modelines.
-     * So the modelines have priority over auto commands.
+     * So the modelines have priority over autocommands.
      */
     /* When reading stdin, the buffer contents always needs writing, so set
      * the changed flag.  Unless in readonly mode: "ls | gview -".
@@ -2159,6 +2159,19 @@ free_buf_options(
     clear_string_option(&buf->b_p_fo);
     clear_string_option(&buf->b_p_flp);
     clear_string_option(&buf->b_p_isk);
+#ifdef FEAT_VARTABS
+    clear_string_option(&buf->b_p_vsts);
+    if (buf->b_p_vsts_nopaste)
+	vim_free(buf->b_p_vsts_nopaste);
+    buf->b_p_vsts_nopaste = NULL;
+    if (buf->b_p_vsts_array)
+	vim_free(buf->b_p_vsts_array);
+    buf->b_p_vsts_array = NULL;
+    clear_string_option(&buf->b_p_vts);
+    if (buf->b_p_vts_array)
+	vim_free(buf->b_p_vts_array);
+    buf->b_p_vts_array = NULL;
+#endif
 #ifdef FEAT_KEYMAP
     clear_string_option(&buf->b_p_keymap);
     keymap_clear(&buf->b_kmap_ga);
@@ -5190,7 +5203,7 @@ ex_buffer_all(exarg_T *eap)
 		win_close(wp, FALSE);
 		wpnext = firstwin;	/* just in case an autocommand does
 					   something strange with windows */
-		tpnext = first_tabpage;	/* start all over...*/
+		tpnext = first_tabpage;	/* start all over... */
 		open_wins = 0;
 	    }
 	    else
@@ -5650,8 +5663,8 @@ bt_prompt(buf_T *buf)
 }
 
 /*
- * Return TRUE if "buf" is a "nofile", "acwrite" or "terminal" buffer.
- * This means the buffer name is not a file name.
+ * Return TRUE if "buf" is a "nofile", "acwrite", "terminal" or "prompt"
+ * buffer.  This means the buffer name is not a file name.
  */
     int
 bt_nofile(buf_T *buf)
@@ -5663,7 +5676,8 @@ bt_nofile(buf_T *buf)
 }
 
 /*
- * Return TRUE if "buf" is a "nowrite", "nofile" or "terminal" buffer.
+ * Return TRUE if "buf" is a "nowrite", "nofile", "terminal" or "prompt"
+ * buffer.
  */
     int
 bt_dontwrite(buf_T *buf)
diff --git a/src/charset.c b/src/charset.c
index 179fc89db..a4816887e 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -812,7 +812,16 @@ vim_strnsize(char_u *s, int len)
  * Also see getvcol() below.
  */
 
-#define RET_WIN_BUF_CHARTABSIZE(wp, buf, p, col) \
+#ifdef FEAT_VARTABS
+# define RET_WIN_BUF_CHARTABSIZE(wp, buf, p, col) \
+    if (*(p) == TAB && (!(wp)->w_p_list || lcs_tab1)) \
+    { \
+	return tabstop_padding(col, (buf)->b_p_ts, (buf)->b_p_vts_array); \
+    } \
+    else \
+	return ptr2cells(p);
+#else
+# define RET_WIN_BUF_CHARTABSIZE(wp, buf, p, col) \
     if (*(p) == TAB && (!(wp)->w_p_list || lcs_tab1)) \
     { \
 	int ts; \
@@ -821,6 +830,7 @@ vim_strnsize(char_u *s, int len)
     } \
     else \
 	return ptr2cells(p);
+#endif
 
     int
 chartabsize(char_u *p, colnr_T col)
@@ -1221,8 +1231,13 @@ win_nolbr_chartabsize(
 
     if (*s == TAB && (!wp->w_p_list || lcs_tab1))
     {
+# ifdef FEAT_VARTABS
+	return tabstop_padding(col, wp->w_buffer->b_p_ts,
+				    wp->w_buffer->b_p_vts_array);
+# else
 	n = wp->w_buffer->b_p_ts;
 	return (int)(n - (col % n));
+# endif
     }
     n = ptr2cells(s);
     /* Add one cell for a double-width character in the last column of the
@@ -1282,6 +1297,9 @@ getvcol(
     char_u	*line;		/* start of the line */
     int		incr;
     int		head;
+#ifdef FEAT_VARTABS
+    int		*vts = wp->w_buffer->b_p_vts_array;
+#endif
     int		ts = wp->w_buffer->b_p_ts;
     int		c;
 
@@ -1332,7 +1350,11 @@ getvcol(
 	    }
 	    /* A tab gets expanded, depending on the current column */
 	    if (c == TAB)
+#ifdef FEAT_VARTABS
+		incr = tabstop_padding(vcol, ts, vts);
+#else
 		incr = ts - (vcol % ts);
+#endif
 	    else
 	    {
 #ifdef FEAT_MBYTE
diff --git a/src/edit.c b/src/edit.c
index 6a636b9e1..d4de825af 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -742,7 +742,14 @@ edit(
 	    mincol = curwin->w_wcol;
 	    validate_cursor_col();
 
-	    if ((int)curwin->w_wcol < mincol - curbuf->b_p_ts
+	    if (
+#ifdef FEAT_VARTABS
+		(int)curwin->w_wcol < mincol - tabstop_at(
+					  get_nolist_virtcol(), curbuf->b_p_ts,
+							 curbuf->b_p_vts_array)
+#else
+		(int)curwin->w_wcol < mincol - curbuf->b_p_ts
+#endif
 		    && curwin->w_wrow == W_WINROW(curwin)
 						 + curwin->w_height - 1 - p_so
 		    && (curwin->w_cursor.lnum != curwin->w_topline
@@ -9329,23 +9336,31 @@ ins_bs(
 	 */
 	if (	   mode == BACKSPACE_CHAR
 		&& ((p_sta && in_indent)
-		    || (get_sts_value() != 0
+		    || ((get_sts_value() != 0
+#ifdef FEAT_VARTABS
+			|| tabstop_count(curbuf->b_p_vsts_array)
+#endif
+			)
 			&& curwin->w_cursor.col > 0
 			&& (*(ml_get_cursor() - 1) == TAB
 			    || (*(ml_get_cursor() - 1) == ' '
 				&& (!*inserted_space_p
 				    || arrow_used))))))
 	{
+#ifndef FEAT_VARTABS
 	    int		ts;
+#endif
 	    colnr_T	vcol;
 	    colnr_T	want_vcol;
 	    colnr_T	start_vcol;
 
 	    *inserted_space_p = FALSE;
+#ifndef FEAT_VARTABS
 	    if (p_sta && in_indent)
 		ts = (int)get_sw_value(curbuf);
 	    else
 		ts = (int)get_sts_value();
+#endif
 	    /* Compute the virtual column where we want to be.  Since
 	     * 'showbreak' may get in the way, need to get the last column of
 	     * the previous character. */
@@ -9354,7 +9369,15 @@ ins_bs(
 	    dec_cursor();
 	    getvcol(curwin, &curwin->w_cursor, NULL, NULL, &want_vcol);
 	    inc_cursor();
+#ifdef FEAT_VARTABS
+	    if (p_sta && in_indent)
+		want_vcol = (want_vcol / curbuf->b_p_sw) * curbuf->b_p_sw;
+	    else
+		want_vcol = tabstop_start(want_vcol, curbuf->b_p_sts,
+						     curbuf->b_p_vsts_array);
+#else
 	    want_vcol = (want_vcol / ts) * ts;
+#endif
 
 	    /* delete characters until we are at or before want_vcol */
 	    while (vcol > want_vcol
@@ -10144,10 +10167,22 @@ ins_tab(void)
 #endif
 
     /*
-     * When nothing special, insert TAB like a normal character
+     * When nothing special, insert TAB like a normal character.
      */
     if (!curbuf->b_p_et
+#ifdef FEAT_VARTABS
+	    && !(p_sta && ind
+		/* These five lines mean 'tabstop' != 'shiftwidth' */
+		&& ((tabstop_count(curbuf->b_p_vts_array) > 1)
+		    || (tabstop_count(curbuf->b_p_vts_array) == 1
+		        && tabstop_first(curbuf->b_p_vts_array)
+						       != get_sw_value(curbuf))
+	            || (tabstop_count(curbuf->b_p_vts_array) == 0
+		        && curbuf->b_p_ts != get_sw_value(curbuf))))
+	    && tabstop_count(curbuf->b_p_vsts_array) == 0
+#else
 	    && !(p_sta && ind && curbuf->b_p_ts != get_sw_value(curbuf))
+#endif
 	    && get_sts_value() == 0)
 	return TRUE;
 
@@ -10162,6 +10197,20 @@ ins_tab(void)
 #endif
     AppendToRedobuff((char_u *)"\t");
 
+#ifdef FEAT_VARTABS
+    if (p_sta && ind)		/* insert tab in indent, use 'shiftwidth' */
+    {
+	temp = (int)curbuf->b_p_sw;
+	temp -= get_nolist_virtcol() % temp;
+    }
+    else if (tabstop_count(curbuf->b_p_vsts_array) > 0 || curbuf->b_p_sts > 0)
+	                        /* use 'softtabstop' when set */
+	temp = tabstop_padding(get_nolist_virtcol(), curbuf->b_p_sts,
+						     curbuf->b_p_vsts_array);
+    else			/* otherwise use 'tabstop' */
+	temp = tabstop_padding(get_nolist_virtcol(), curbuf->b_p_ts,
+						     curbuf->b_p_vts_array);
+#else
     if (p_sta && ind)		/* insert tab in indent, use 'shiftwidth' */
 	temp = (int)get_sw_value(curbuf);
     else if (curbuf->b_p_sts != 0) /* use 'softtabstop' when set */
@@ -10169,6 +10218,7 @@ ins_tab(void)
     else			/* otherwise use 'tabstop' */
 	temp = (int)curbuf->b_p_ts;
     temp -= get_nolist_virtcol() % temp;
+#endif
 
     /*
      * Insert the first space with ins_char().	It will delete one char in
@@ -10193,7 +10243,13 @@ ins_tab(void)
     /*
      * When 'expandtab' not set: Replace spaces by TABs where possible.
      */
+#ifdef FEAT_VARTABS
+    if (!curbuf->b_p_et && (tabstop_count(curbuf->b_p_vsts_array) > 0
+                            || get_sts_value() > 0
+			    || (p_sta && ind)))
+#else
     if (!curbuf->b_p_et && (get_sts_value() || (p_sta && ind)))
+#endif
     {
 	char_u		*ptr;
 #ifdef FEAT_VREPLACE
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 7325f5dfc..0cd7527f7 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -6436,6 +6436,9 @@ f_has(typval_T *argvars, typval_T *rettv)
 	"user-commands",    /* was accidentally included in 5.4 */
 	"user_commands",
 #endif
+#ifdef FEAT_VARTABS
+	"vartabs",
+#endif
 #ifdef FEAT_VIMINFO
 	"viminfo",
 #endif
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 60d72023c..53334342c 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -673,12 +673,17 @@ ex_retab(exarg_T *eap)
     long	vcol;
     long	start_col = 0;		/* For start of white-space string */
     long	start_vcol = 0;		/* For start of white-space string */
-    int		temp;
     long	old_len;
     char_u	*ptr;
     char_u	*new_line = (char_u *)1;    /* init to non-NULL */
     int		did_undo;		/* called u_save for current line */
+#ifdef FEAT_VARTABS
+    int		*new_ts = 0;
+    char_u	*new_ts_str;		/* string value of tab argument */
+#else
+    int		temp;
     int		new_ts;
+#endif
     int		save_list;
     linenr_T	first_line = 0;		/* first changed line */
     linenr_T	last_line = 0;		/* last changed line */
@@ -686,6 +691,23 @@ ex_retab(exarg_T *eap)
     save_list = curwin->w_p_list;
     curwin->w_p_list = 0;	    /* don't want list mode here */
 
+#ifdef FEAT_VARTABS
+    new_ts_str = eap->arg;
+    if (!tabstop_set(eap->arg, &new_ts))
+	return;
+    while (vim_isdigit(*(eap->arg)) || *(eap->arg) == ',')
+	++(eap->arg);
+
+    // This ensures that either new_ts and new_ts_str are freshly allocated,
+    // or new_ts points to an existing array and new_ts_str is null.
+    if (new_ts == 0)
+    {
+	new_ts = curbuf->b_p_vts_array;
+	new_ts_str = NULL;
+    }
+    else
+	new_ts_str = vim_strnsave(new_ts_str, eap->arg - new_ts_str);
+#else
     new_ts = getdigits(&(eap->arg));
     if (new_ts < 0)
     {
@@ -694,6 +716,7 @@ ex_retab(exarg_T *eap)
     }
     if (new_ts == 0)
 	new_ts = curbuf->b_p_ts;
+#endif
     for (lnum = eap->line1; !got_int && lnum <= eap->line2; ++lnum)
     {
 	ptr = ml_get(lnum);
@@ -726,6 +749,16 @@ ex_retab(exarg_T *eap)
 		    num_tabs = 0;
 		    if (!curbuf->b_p_et)
 		    {
+#ifdef FEAT_VARTABS
+			int t, s;
+
+			tabstop_fromto(start_vcol, vcol,
+				       tabstop_count(new_ts)? 0: curbuf->b_p_ts,
+				       new_ts,
+				       &t, &s);
+			num_tabs = t;
+			num_spaces = s;
+#else
 			temp = new_ts - (start_vcol % new_ts);
 			if (num_spaces >= temp)
 			{
@@ -734,6 +767,7 @@ ex_retab(exarg_T *eap)
 			}
 			num_tabs += num_spaces / new_ts;
 			num_spaces -= (num_spaces / new_ts) * new_ts;
+#endif
 		    }
 		    if (curbuf->b_p_et || got_tab ||
 					(num_spaces + num_tabs < len))
@@ -791,14 +825,53 @@ ex_retab(exarg_T *eap)
     if (got_int)
 	EMSG(_(e_interr));
 
+#ifdef FEAT_VARTABS
+    // If a single value was given then it can be considered equal to
+    // either the value of 'tabstop' or the value of 'vartabstop'.
+    if (tabstop_count(curbuf->b_p_vts_array) == 0
+	&& tabstop_count(new_ts) == 1
+	&& curbuf->b_p_ts == tabstop_first(new_ts))
+	; /* not changed */
+    else if (tabstop_count(curbuf->b_p_vts_array) > 0
+        && tabstop_eq(curbuf->b_p_vts_array, new_ts))
+	; /* not changed */
+    else
+	redraw_curbuf_later(NOT_VALID);
+#else
     if (curbuf->b_p_ts != new_ts)
 	redraw_curbuf_later(NOT_VALID);
+#endif
     if (first_line != 0)
 	changed_lines(first_line, 0, last_line + 1, 0L);
 
     curwin->w_p_list = save_list;	/* restore 'list' */
 
+#ifdef FEAT_VARTABS
+    if (new_ts_str != NULL)		/* set the new tabstop */
+    {
+	// If 'vartabstop' is in use or if the value given to retab has more
+	// than one tabstop then update 'vartabstop'.
+	int *old_vts_ary = curbuf->b_p_vts_array;
+
+	if (tabstop_count(old_vts_ary) > 0 || tabstop_count(new_ts) > 1)
+	{
+	    set_string_option_direct((char_u *)"vts", -1, new_ts_str,
+							OPT_FREE|OPT_LOCAL, 0);
+	    vim_free(new_ts_str);
+	    curbuf->b_p_vts_array = new_ts;
+	    vim_free(old_vts_ary);
+	}
+	else
+	{
+	    // 'vartabstop' wasn't in use and a single value was given to
+	    // retab then update 'tabstop'.
+	    curbuf->b_p_ts = tabstop_first(new_ts);
+	    vim_free(new_ts);
+	}
+    }
+#else
     curbuf->b_p_ts = new_ts;
+#endif
     coladvance(curwin->w_curswant);
 
     u_clearline();
diff --git a/src/feature.h b/src/feature.h
index 5b915b838..762a70cee 100644
--- a/src/feature.h
+++ b/src/feature.h
@@ -806,6 +806,13 @@
 #endif
 
 /*
+ * +vartabs		'vartabstop' and 'varsofttabstop' options.
+ */
+#ifdef FEAT_BIG
+# define FEAT_VARTABS
+#endif
+
+/*
  * Preferences:
  * ============
  */
diff --git a/src/gui_beval.c b/src/gui_beval.c
index 8c1cd9696..7e4625080 100644
--- a/src/gui_beval.c
+++ b/src/gui_beval.c
@@ -130,6 +130,9 @@ gui_mch_create_beval_area(
 	beval->msg = mesg;
 	beval->msgCB = mesgCB;
 	beval->clientData = clientData;
+#ifdef FEAT_VARTABS
+	beval->vts = NULL;
+#endif
 
 	/*
 	 * Set up event handler which will keep its eyes on the pointer,
@@ -172,6 +175,10 @@ gui_mch_destroy_beval_area(BalloonEval *beval)
 # else
     XtDestroyWidget(beval->balloonShell);
 # endif
+# ifdef FEAT_VARTABS
+    if (beval->vts)
+	vim_free(beval->vts);
+# endif
     vim_free(beval);
 }
 #endif
diff --git a/src/gui_w32.c b/src/gui_w32.c
index 49aa1e0bd..855381108 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -8934,6 +8934,9 @@ gui_mch_create_beval_area(
 	beval->msg = mesg;
 	beval->msgCB = mesgCB;
 	beval->clientData = clientData;
+#ifdef FEAT_VARTABS
+	beval->vts = NULL;
+#endif
 
 	InitCommonControls();
 	cur_beval = beval;
@@ -8990,6 +8993,10 @@ TrackUserActivity(UINT uMsg)
     void
 gui_mch_destroy_beval_area(BalloonEval *beval)
 {
+#ifdef FEAT_VARTABS
+    if (beval->vts)
+	vim_free(beval->vts);
+#endif
     vim_free(beval);
 }
 #endif /* FEAT_BEVAL_GUI */
diff --git a/src/hardcopy.c b/src/hardcopy.c
index 420ceb763..44e9d4fe8 100644
--- a/src/hardcopy.c
+++ b/src/hardcopy.c
@@ -915,7 +915,12 @@ hardcopy_line(
 	if (line[col] == TAB || tab_spaces != 0)
 	{
 	    if (tab_spaces == 0)
+#ifdef FEAT_VARTABS
+		tab_spaces = tabstop_padding(print_pos, curbuf->b_p_ts,
+							curbuf->b_p_vts_array);
+#else
 		tab_spaces = (int)(curbuf->b_p_ts - (print_pos % curbuf->b_p_ts));
+#endif
 
 	    while (tab_spaces > 0)
 	    {
diff --git a/src/message.c b/src/message.c
index fd087a4a7..4dac5ae04 100644
--- a/src/message.c
+++ b/src/message.c
@@ -1831,7 +1831,12 @@ msg_prt_line(char_u *s, int list)
 	    if (c == TAB && (!list || lcs_tab1))
 	    {
 		/* tab amount depends on current column */
+#ifdef FEAT_VARTABS
+		n_extra = tabstop_padding(col, curbuf->b_p_ts,
+						    curbuf->b_p_vts_array) - 1;
+#else
 		n_extra = curbuf->b_p_ts - col % curbuf->b_p_ts - 1;
+#endif
 		if (!list)
 		{
 		    c = ' ';
diff --git a/src/misc1.c b/src/misc1.c
index d797a0bc6..5242ca572 100644
--- a/src/misc1.c
+++ b/src/misc1.c
@@ -36,7 +36,12 @@ static garray_T	ga_users;
     int
 get_indent(void)
 {
+#ifdef FEAT_VARTABS
+    return get_indent_str_vtab(ml_get_curline(), (int)curbuf->b_p_ts,
+						 curbuf->b_p_vts_array, FALSE);
+#else
     return get_indent_str(ml_get_curline(), (int)curbuf->b_p_ts, FALSE);
+#endif
 }
 
 /*
@@ -45,7 +50,12 @@ get_indent(void)
     int
 get_indent_lnum(linenr_T lnum)
 {
+#ifdef FEAT_VARTABS
+    return get_indent_str_vtab(ml_get(lnum), (int)curbuf->b_p_ts,
+						 curbuf->b_p_vts_array, FALSE);
+#else
     return get_indent_str(ml_get(lnum), (int)curbuf->b_p_ts, FALSE);
+#endif
 }
 
 #if defined(FEAT_FOLDING) || defined(PROTO)
@@ -56,7 +66,12 @@ get_indent_lnum(linenr_T lnum)
     int
 get_indent_buf(buf_T *buf, linenr_T lnum)
 {
+#ifdef FEAT_VARTABS
+    return get_indent_str_vtab(ml_get_buf(buf, lnum, FALSE),
+			       (int)curbuf->b_p_ts, buf->b_p_vts_array, FALSE);
+#else
     return get_indent_str(ml_get_buf(buf, lnum, FALSE), (int)buf->b_p_ts, FALSE);
+#endif
 }
 #endif
 
@@ -91,6 +106,37 @@ get_indent_str(
     return count;
 }
 
+#ifdef FEAT_VARTABS
+/*
+ * Count the size (in window cells) of the indent in line "ptr", using
+ * variable tabstops.
+ * if "list" is TRUE, count only screen size for tabs.
+ */
+    int
+get_indent_str_vtab(char_u *ptr, int ts, int *vts, int list)
+{
+    int		count = 0;
+
+    for ( ; *ptr; ++ptr)
+    {
+	if (*ptr == TAB)    /* count a tab for what it is worth */
+	{
+	    if (!list || lcs_tab1)
+		count += tabstop_padding(count, ts, vts);
+	    else
+		/* In list mode, when tab is not set, count screen char width
+		 * for Tab, displays: ^I */
+		count += ptr2cells(ptr);
+	}
+	else if (*ptr == ' ')
+	    ++count;		/* count a space for one */
+	else
+	    break;
+    }
+    return count;
+}
+#endif
+
 /*
  * Set the indent of the current line.
  * Leaves the cursor on the first non-blank in the line.
@@ -115,6 +161,9 @@ set_indent(
     int		line_len;
     int		doit = FALSE;
     int		ind_done = 0;	    /* measured in spaces */
+#ifdef FEAT_VARTABS
+    int		ind_col = 0;
+#endif
     int		tab_pad;
     int		retval = FALSE;
     int		orig_char_len = -1; /* number of initial whitespace chars when
@@ -147,8 +196,13 @@ set_indent(
 	    {
 		if (*p == TAB)
 		{
+#ifdef FEAT_VARTABS
+		    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+							curbuf->b_p_vts_array);
+#else
 		    tab_pad = (int)curbuf->b_p_ts
 					   - (ind_done % (int)curbuf->b_p_ts);
+#endif
 		    /* stop if this tab will overshoot the target */
 		    if (todo < tab_pad)
 			break;
@@ -165,23 +219,51 @@ set_indent(
 		++p;
 	    }
 
+#ifdef FEAT_VARTABS
+	    /* These diverge from this point. */
+	    ind_col = ind_done;
+#endif
 	    /* Set initial number of whitespace chars to copy if we are
 	     * preserving indent but expandtab is set */
 	    if (curbuf->b_p_et)
 		orig_char_len = ind_len;
 
 	    /* Fill to next tabstop with a tab, if possible */
+#ifdef FEAT_VARTABS
+	    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+						curbuf->b_p_vts_array);
+#else
 	    tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
+#endif
 	    if (todo >= tab_pad && orig_char_len == -1)
 	    {
 		doit = TRUE;
 		todo -= tab_pad;
 		++ind_len;
 		/* ind_done += tab_pad; */
+#ifdef FEAT_VARTABS
+		ind_col += tab_pad;
+#endif
 	    }
 	}
 
 	/* count tabs required for indent */
+#ifdef FEAT_VARTABS
+	for (;;)
+	{
+	    tab_pad = tabstop_padding(ind_col, curbuf->b_p_ts,
+							curbuf->b_p_vts_array);
+	    if (todo < tab_pad)
+		break;
+	    if (*p != TAB)
+		doit = TRUE;
+	    else
+		++p;
+	    todo -= tab_pad;
+	    ++ind_len;
+	    ind_col += tab_pad;
+	}
+#else
 	while (todo >= (int)curbuf->b_p_ts)
 	{
 	    if (*p != TAB)
@@ -192,6 +274,7 @@ set_indent(
 	    ++ind_len;
 	    /* ind_done += (int)curbuf->b_p_ts; */
 	}
+#endif
     }
     /* count spaces required for indent */
     while (todo > 0)
@@ -266,8 +349,13 @@ set_indent(
 	    {
 		if (*p == TAB)
 		{
+#ifdef FEAT_VARTABS
+		    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+							curbuf->b_p_vts_array);
+#else
 		    tab_pad = (int)curbuf->b_p_ts
 					   - (ind_done % (int)curbuf->b_p_ts);
+#endif
 		    /* stop if this tab will overshoot the target */
 		    if (todo < tab_pad)
 			break;
@@ -283,21 +371,42 @@ set_indent(
 	    }
 
 	    /* Fill to next tabstop with a tab, if possible */
+#ifdef FEAT_VARTABS
+	    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+						curbuf->b_p_vts_array);
+#else
 	    tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
+#endif
 	    if (todo >= tab_pad)
 	    {
 		*s++ = TAB;
 		todo -= tab_pad;
+#ifdef FEAT_VARTABS
+		ind_done += tab_pad;
+#endif
 	    }
 
 	    p = skipwhite(p);
 	}
 
+#ifdef FEAT_VARTABS
+	for (;;)
+	{
+	    tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+							curbuf->b_p_vts_array);
+	    if (todo < tab_pad)
+		break;
+	    *s++ = TAB;
+	    todo -= tab_pad;
+	    ind_done += tab_pad;
+	}
+#else
 	while (todo >= (int)curbuf->b_p_ts)
 	{
 	    *s++ = TAB;
 	    todo -= (int)curbuf->b_p_ts;
 	}
+#endif
     }
     while (todo > 0)
     {
@@ -350,6 +459,9 @@ copy_indent(int size, char_u *src)
     int		tab_pad;
     int		ind_done;
     int		round;
+#ifdef FEAT_VARTABS
+    int		ind_col;
+#endif
 
     /* Round 1: compute the number of characters needed for the indent
      * Round 2: copy the characters. */
@@ -358,6 +470,9 @@ copy_indent(int size, char_u *src)
 	todo = size;
 	ind_len = 0;
 	ind_done = 0;
+#ifdef FEAT_VARTABS
+	ind_col = 0;
+#endif
 	s = src;
 
 	/* Count/copy the usable portion of the source line */
@@ -365,18 +480,29 @@ copy_indent(int size, char_u *src)
 	{
 	    if (*s == TAB)
 	    {
+#ifdef FEAT_VARTABS
+		tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+							curbuf->b_p_vts_array);
+#else
 		tab_pad = (int)curbuf->b_p_ts
 					   - (ind_done % (int)curbuf->b_p_ts);
+#endif
 		/* Stop if this tab will overshoot the target */
 		if (todo < tab_pad)
 		    break;
 		todo -= tab_pad;
 		ind_done += tab_pad;
+#ifdef FEAT_VARTABS
+		ind_col += tab_pad;
+#endif
 	    }
 	    else
 	    {
 		--todo;
 		++ind_done;
+#ifdef FEAT_VARTABS
+		++ind_col;
+#endif
 	    }
 	    ++ind_len;
 	    if (p != NULL)
@@ -385,22 +511,48 @@ copy_indent(int size, char_u *src)
 	}
 
 	/* Fill to next tabstop with a tab, if possible */
+#ifdef FEAT_VARTABS
+	tab_pad = tabstop_padding(ind_done, curbuf->b_p_ts,
+							curbuf->b_p_vts_array);
+#else
 	tab_pad = (int)curbuf->b_p_ts - (ind_done % (int)curbuf->b_p_ts);
+#endif
 	if (todo >= tab_pad && !curbuf->b_p_et)
 	{
 	    todo -= tab_pad;
 	    ++ind_len;
+#ifdef FEAT_VARTABS
+	    ind_col += tab_pad;
+#endif
 	    if (p != NULL)
 		*p++ = TAB;
 	}
 
 	/* Add tabs required for indent */
-	while (todo >= (int)curbuf->b_p_ts && !curbuf->b_p_et)
+	if (!curbuf->b_p_et)
 	{
-	    todo -= (int)curbuf->b_p_ts;
-	    ++ind_len;
-	    if (p != NULL)
-		*p++ = TAB;
+#ifdef FEAT_VARTABS
+	    for (;;)
+	    {
+		tab_pad = tabstop_padding(ind_col, curbuf->b_p_ts,
+							curbuf->b_p_vts_array);
+		if (todo < tab_pad)
+		    break;
+		todo -= tab_pad;
+		++ind_len;
+		ind_col += tab_pad;
+		if (p != NULL)
+		    *p++ = TAB;
+	    }
+#else
+	    while (todo >= (int)curbuf->b_p_ts)
+	    {
+		todo -= (int)curbuf->b_p_ts;
+		++ind_len;
+		if (p != NULL)
+		    *p++ = TAB;
+	    }
+#endif
 	}
 
 	/* Count/add spaces required for indent */
@@ -497,6 +649,9 @@ get_breakindent_win(
     static long	    prev_ts     = 0L; /* cached tabstop value */
     static char_u   *prev_line = NULL; /* cached pointer to line */
     static varnumber_T prev_tick = 0;   /* changedtick of cached value */
+#ifdef FEAT_VARTABS
+    static int      *prev_vts = NULL;    /* cached vartabs values */
+#endif
     int		    bri = 0;
     /* window width minus window margin space, i.e. what rests for text */
     const int	    eff_wwidth = wp->w_width
@@ -506,13 +661,24 @@ get_breakindent_win(
 
     /* used cached indent, unless pointer or 'tabstop' changed */
     if (prev_line != line || prev_ts != wp->w_buffer->b_p_ts
-				  || prev_tick != CHANGEDTICK(wp->w_buffer))
+	    || prev_tick != CHANGEDTICK(wp->w_buffer)
+#ifdef FEAT_VARTABS
+	    || prev_vts != wp->w_buffer->b_p_vts_array
+#endif
+	)
     {
 	prev_line = line;
 	prev_ts = wp->w_buffer->b_p_ts;
 	prev_tick = CHANGEDTICK(wp->w_buffer);
+#ifdef FEAT_VARTABS
+	prev_vts = wp->w_buffer->b_p_vts_array;
+	prev_indent = get_indent_str_vtab(line,
+				     (int)wp->w_buffer->b_p_ts,
+				    wp->w_buffer->b_p_vts_array, wp->w_p_list);
+#else
 	prev_indent = get_indent_str(line,
 				     (int)wp->w_buffer->b_p_ts, wp->w_p_list);
+#endif
     }
     bri = prev_indent + wp->w_p_brishift;
 
@@ -741,7 +907,12 @@ open_line(
 	/*
 	 * count white space on current line
 	 */
+#ifdef FEAT_VARTABS
+	newindent = get_indent_str_vtab(saved_line, curbuf->b_p_ts,
+						 curbuf->b_p_vts_array, FALSE);
+#else
 	newindent = get_indent_str(saved_line, (int)curbuf->b_p_ts, FALSE);
+#endif
 	if (newindent == 0 && !(flags & OPENLINE_COM_LIST))
 	    newindent = second_line_indent; /* for ^^D command in insert mode */
 
@@ -1264,7 +1435,13 @@ open_line(
 					|| do_si
 #endif
 							   )
-			newindent = get_indent_str(leader, (int)curbuf->b_p_ts, FALSE);
+#ifdef FEAT_VARTABS
+			newindent = get_indent_str_vtab(leader, curbuf->b_p_ts,
+						 curbuf->b_p_vts_array, FALSE);
+#else
+			newindent = get_indent_str(leader,
+						   (int)curbuf->b_p_ts, FALSE);
+#endif
 
 		    /* Add the indent offset */
 		    if (newindent + off < 0)
diff --git a/src/ops.c b/src/ops.c
index 65fc75e20..2dbc74889 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -398,6 +398,9 @@ shift_block(oparg_T *oap, int amount)
     char_u		*newp, *oldp;
     int			oldcol = curwin->w_cursor.col;
     int			p_sw = (int)get_sw_value(curbuf);
+#ifdef FEAT_VARTABS
+    int			*p_vts = curbuf->b_p_vts_array;
+#endif
     int			p_ts = (int)curbuf->b_p_ts;
     struct block_def	bd;
     int			incr;
@@ -459,12 +462,19 @@ shift_block(oparg_T *oap, int amount)
 	}
 	/* OK, now total=all the VWS reqd, and textstart points at the 1st
 	 * non-ws char in the block. */
+#ifdef FEAT_VARTABS
+	if (!curbuf->b_p_et)
+	    tabstop_fromto(ws_vcol, ws_vcol + total, p_ts, p_vts, &i, &j);
+	else
+	    j = total;
+#else
 	if (!curbuf->b_p_et)
 	    i = ((ws_vcol % p_ts) + total) / p_ts; /* number of tabs */
 	if (i)
 	    j = ((ws_vcol % p_ts) + total) % p_ts; /* number of spp */
 	else
 	    j = total;
+#endif
 	/* if we're splitting a TAB, allow for it */
 	bd.textcol -= bd.pre_whitesp_c - (bd.startspaces != 0);
 	len = (int)STRLEN(bd.textstart) + 1;
@@ -3697,10 +3707,19 @@ do_put(
 	{
 	    /* Don't need to insert spaces when "p" on the last position of a
 	     * tab or "P" on the first position. */
+#ifdef FEAT_VARTABS
+	    int viscol = getviscol();
+	    if (dir == FORWARD
+		    ? tabstop_padding(viscol, curbuf->b_p_ts,
+						    curbuf->b_p_vts_array) != 1
+		    : curwin->w_cursor.coladd > 0)
+		coladvance_force(viscol);
+#else
 	    if (dir == FORWARD
 		    ? (int)curwin->w_cursor.coladd < curbuf->b_p_ts - 1
 						: curwin->w_cursor.coladd > 0)
 		coladvance_force(getviscol());
+#endif
 	    else
 		curwin->w_cursor.coladd = 0;
 	}
diff --git a/src/option.c b/src/option.c
index cf774ac23..94cd7aa52 100644
--- a/src/option.c
+++ b/src/option.c
@@ -182,6 +182,10 @@
 # define PV_UDF		OPT_BUF(BV_UDF)
 #endif
 #define PV_WM		OPT_BUF(BV_WM)
+#ifdef FEAT_VARTABS
+# define PV_VSTS		OPT_BUF(BV_VSTS)
+# define PV_VTS		OPT_BUF(BV_VTS)
+#endif
 
 /*
  * Definition of the PV_ values for window-local options.
@@ -371,6 +375,10 @@ static int	p_tx;
 static int	p_udf;
 #endif
 static long	p_wm;
+#ifdef FEAT_VARTABS
+static char_u	*p_vsts;
+static char_u	*p_vts;
+#endif
 #ifdef FEAT_KEYMAP
 static char_u	*p_keymap;
 #endif
@@ -390,6 +398,9 @@ static int	p_et_nopaste;
 static long	p_sts_nopaste;
 static long	p_tw_nopaste;
 static long	p_wm_nopaste;
+#ifdef FEAT_VARTABS
+static char_u	*p_vsts_nopaste;
+#endif
 
 struct vimoption
 {
@@ -2925,6 +2936,24 @@ static struct vimoption options[] =
     {"updatetime",  "ut",   P_NUM|P_VI_DEF,
 			    (char_u *)&p_ut, PV_NONE,
 			    {(char_u *)4000L, (char_u *)0L} SCRIPTID_INIT},
+    {"varsofttabstop", "vsts",  P_STRING|P_VI_DEF|P_VIM|P_COMMA,
+#ifdef FEAT_VARTABS
+			    (char_u *)&p_vsts, PV_VSTS,
+			    {(char_u *)"", (char_u *)0L}
+#else
+			    (char_u *)NULL, PV_NONE,
+			    {(char_u *)"", (char_u *)NULL}
+#endif
+			    SCRIPTID_INIT},
+    {"vartabstop",  "vts",  P_STRING|P_VI_DEF|P_VIM|P_RBUF|P_COMMA,
+#ifdef FEAT_VARTABS
+			    (char_u *)&p_vts, PV_VTS,
+			    {(char_u *)"", (char_u *)0L}
+#else
+			    (char_u *)NULL, PV_NONE,
+			    {(char_u *)"", (char_u *)NULL}
+#endif
+			    SCRIPTID_INIT},
     {"verbose",	    "vbs",  P_NUM|P_VI_DEF,
 			    (char_u *)&p_verbose, PV_NONE,
 			    {(char_u *)0L, (char_u *)0L} SCRIPTID_INIT},
@@ -5608,6 +5637,10 @@ didset_options2(void)
     /* Parse default for 'clipboard' */
     (void)check_clipboard_option();
 #endif
+#ifdef FEAT_VARTABS
+    tabstop_set(curbuf->b_p_vsts, &curbuf->b_p_vsts_array);
+    tabstop_set(curbuf->b_p_vts,  &curbuf->b_p_vts_array);
+#endif
 }
 
 /*
@@ -5725,6 +5758,10 @@ check_buf_options(buf_T *buf)
 #ifdef FEAT_MBYTE
     check_string_option(&buf->b_p_menc);
 #endif
+#ifdef FEAT_VARTABS
+    check_string_option(&buf->b_p_vsts);
+    check_string_option(&buf->b_p_vts);
+#endif
 }
 
 /*
@@ -7472,6 +7509,88 @@ did_set_string_option(
     }
 #endif
 
+#ifdef FEAT_VARTABS
+    /* 'varsofttabstop' */
+    else if (varp == &(curbuf->b_p_vsts))
+    {
+	char_u *cp;
+
+	if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1]))
+	{
+	    if (curbuf->b_p_vsts_array)
+	    {
+		vim_free(curbuf->b_p_vsts_array);
+		curbuf->b_p_vsts_array = 0;
+	    }
+	}
+	else
+	{
+	    for (cp = *varp; *cp; ++cp)
+	    {
+		if (vim_isdigit(*cp))
+		    continue;
+		if (*cp == ',' && cp > *varp && *(cp-1) != ',')
+		    continue;
+		errmsg = e_invarg;
+		break;
+	    }
+	    if (errmsg == NULL)
+	    {
+		int *oldarray = curbuf->b_p_vsts_array;
+		if (tabstop_set(*varp, &(curbuf->b_p_vsts_array)))
+		{
+		    if (oldarray)
+			vim_free(oldarray);
+		}
+		else
+		    errmsg = e_invarg;
+	    }
+	}
+    }
+
+    /* 'vartabstop' */
+    else if (varp == &(curbuf->b_p_vts))
+    {
+	char_u *cp;
+
+	if (!(*varp)[0] || ((*varp)[0] == '0' && !(*varp)[1]))
+	{
+	    if (curbuf->b_p_vts_array)
+	    {
+		vim_free(curbuf->b_p_vts_array);
+		curbuf->b_p_vts_array = NULL;
+	    }
+	}
+	else
+	{
+	    for (cp = *varp; *cp; ++cp)
+	    {
+		if (vim_isdigit(*cp))
+		    continue;
+		if (*cp == ',' && cp > *varp && *(cp-1) != ',')
+		    continue;
+		errmsg = e_invarg;
+		break;
+	    }
+	    if (errmsg == NULL)
+	    {
+		int *oldarray = curbuf->b_p_vts_array;
+		if (tabstop_set(*varp, &(curbuf->b_p_vts_array)))
+		{
+		    if (oldarray)
+			vim_free(oldarray);
+#ifdef FEAT_FOLDING
+		    if (foldmethodIsIndent(curwin))
+			foldUpdateAll(curwin);
+#endif /* FEAT_FOLDING */
+		}
+		else
+		    errmsg = e_invarg;
+	    }
+	}
+    }
+#endif
+
     /* Options that are a list of flags. */
     else
     {
@@ -8780,7 +8899,14 @@ set_num_option(
     if (curbuf->b_p_sw < 0)
     {
 	errmsg = e_positive;
+#ifdef FEAT_VARTABS
+	// Use the first 'vartabstop' value, or 'tabstop' if vts isn't in use.
+	curbuf->b_p_sw = tabstop_count(curbuf->b_p_vts_array) > 0
+	               ? tabstop_first(curbuf->b_p_vts_array)
+		       : curbuf->b_p_ts;
+#else
 	curbuf->b_p_sw = curbuf->b_p_ts;
+#endif
     }
 
     /*
@@ -10814,6 +10940,10 @@ get_varp(struct vimoption *p)
 #ifdef FEAT_SIGNS
 	case PV_SCL:	return (char_u *)&(curwin->w_p_scl);
 #endif
+#ifdef FEAT_VARTABS
+	case PV_VSTS:	return (char_u *)&(curbuf->b_p_vsts);
+	case PV_VTS:	return (char_u *)&(curbuf->b_p_vts);
+#endif
 	default:	IEMSG(_("E356: get_varp ERROR"));
     }
     /* always return a valid pointer to avoid a crash! */
@@ -11138,6 +11268,15 @@ buf_copy_options(buf_T *buf, int flags)
 #endif
 	    buf->b_p_sts = p_sts;
 	    buf->b_p_sts_nopaste = p_sts_nopaste;
+#ifdef FEAT_VARTABS
+	    buf->b_p_vsts = vim_strsave(p_vsts);
+	    if (p_vsts && p_vsts != empty_option)
+		tabstop_set(p_vsts, &buf->b_p_vsts_array);
+	    else
+		buf->b_p_vsts_array = 0;
+	    buf->b_p_vsts_nopaste = p_vsts_nopaste
+				 ? vim_strsave(p_vsts_nopaste) : NULL;
+#endif
 	    buf->b_p_sn = p_sn;
 #ifdef FEAT_COMMENTS
 	    buf->b_p_com = vim_strsave(p_com);
@@ -11259,12 +11398,27 @@ buf_copy_options(buf_T *buf, int flags)
 	     * or to a help buffer.
 	     */
 	    if (dont_do_help)
+	    {
 		buf->b_p_isk = save_p_isk;
+#ifdef FEAT_VARTABS
+		if (p_vts && p_vts != empty_option && !buf->b_p_vts_array)
+		    tabstop_set(p_vts, &buf->b_p_vts_array);
+		else
+		    buf->b_p_vts_array = NULL;
+#endif
+	    }
 	    else
 	    {
 		buf->b_p_isk = vim_strsave(p_isk);
 		did_isk = TRUE;
 		buf->b_p_ts = p_ts;
+#ifdef FEAT_VARTABS
+		buf->b_p_vts = vim_strsave(p_vts);
+		if (p_vts && p_vts != empty_option && !buf->b_p_vts_array)
+		    tabstop_set(p_vts, &buf->b_p_vts_array);
+		else
+		    buf->b_p_vts_array = NULL;
+#endif
 		buf->b_help = FALSE;
 		if (buf->b_p_bt[0] == 'h')
 		    clear_string_option(&buf->b_p_bt);
@@ -12084,6 +12238,12 @@ paste_option_changed(void)
 		buf->b_p_sts_nopaste = buf->b_p_sts;
 		buf->b_p_ai_nopaste = buf->b_p_ai;
 		buf->b_p_et_nopaste = buf->b_p_et;
+#ifdef FEAT_VARTABS
+		if (buf->b_p_vsts_nopaste)
+		    vim_free(buf->b_p_vsts_nopaste);
+		buf->b_p_vsts_nopaste = buf->b_p_vsts && buf->b_p_vsts != empty_option
+				     ? vim_strsave(buf->b_p_vsts) : NULL;
+#endif
 	    }
 
 	    /* save global options */
@@ -12102,6 +12262,11 @@ paste_option_changed(void)
 	    p_sts_nopaste = p_sts;
 	    p_tw_nopaste = p_tw;
 	    p_wm_nopaste = p_wm;
+#ifdef FEAT_VARTABS
+	    if (p_vsts_nopaste)
+		vim_free(p_vsts_nopaste);
+	    p_vsts_nopaste = p_vsts && p_vsts != empty_option ? vim_strsave(p_vsts) : NULL;
+#endif
 	}
 
 	/*
@@ -12116,6 +12281,14 @@ paste_option_changed(void)
 	    buf->b_p_sts = 0;	    /* softtabstop is 0 */
 	    buf->b_p_ai = 0;	    /* no auto-indent */
 	    buf->b_p_et = 0;	    /* no expandtab */
+#ifdef FEAT_VARTABS
+	    if (buf->b_p_vsts)
+		free_string_option(buf->b_p_vsts);
+	    buf->b_p_vsts = empty_option;
+	    if (buf->b_p_vsts_array)
+		vim_free(buf->b_p_vsts_array);
+	    buf->b_p_vsts_array = 0;
+#endif
 	}
 
 	/* set global options */
@@ -12135,6 +12308,11 @@ paste_option_changed(void)
 	p_wm = 0;
 	p_sts = 0;
 	p_ai = 0;
+#ifdef FEAT_VARTABS
+	if (p_vsts)
+	    free_string_option(p_vsts);
+	p_vsts = empty_option;
+#endif
     }
 
     /*
@@ -12150,6 +12328,18 @@ paste_option_changed(void)
 	    buf->b_p_sts = buf->b_p_sts_nopaste;
 	    buf->b_p_ai = buf->b_p_ai_nopaste;
 	    buf->b_p_et = buf->b_p_et_nopaste;
+#ifdef FEAT_VARTABS
+	    if (buf->b_p_vsts)
+		free_string_option(buf->b_p_vsts);
+	    buf->b_p_vsts = buf->b_p_vsts_nopaste
+			 ? vim_strsave(buf->b_p_vsts_nopaste) : empty_option;
+	    if (buf->b_p_vsts_array)
+		vim_free(buf->b_p_vsts_array);
+	    if (buf->b_p_vsts && buf->b_p_vsts != empty_option)
+		tabstop_set(buf->b_p_vsts, &buf->b_p_vsts_array);
+	    else
+		buf->b_p_vsts_array = 0;
+#endif
 	}
 
 	/* restore global options */
@@ -12170,6 +12360,11 @@ paste_option_changed(void)
 	p_sts = p_sts_nopaste;
 	p_tw = p_tw_nopaste;
 	p_wm = p_wm_nopaste;
+#ifdef FEAT_VARTABS
+	if (p_vsts)
+	    free_string_option(p_vsts);
+	p_vsts = p_vsts_nopaste ? vim_strsave(p_vsts_nopaste) : empty_option;
+#endif
     }
 
     old_p_paste = p_paste;
@@ -12510,6 +12705,295 @@ check_ff_value(char_u *p)
     return check_opt_strings(p, p_ff_values, FALSE);
 }
 
+#ifdef FEAT_VARTABS
+
+/*
+ * Set the integer values corresponding to the string setting of 'vartabstop'.
+ */
+    int
+tabstop_set(char_u *var, int **array)
+{
+    int valcount = 1;
+    int t;
+    char_u *cp;
+
+    if ((!var[0] || (var[0] == '0' && !var[1])))
+    {
+	*array = NULL;
+	return TRUE;
+    }
+
+    for (cp = var; *cp; ++cp)
+    {
+	if (cp == var || *(cp - 1) == ',')
+	{
+	    char_u *end;
+	    if (strtol((char *)cp, (char **)&end, 10) <= 0)
+	    {
+		if (cp != end)
+		    EMSG(_(e_positive));
+		else
+		    EMSG(_(e_invarg));
+		return FALSE;
+	    }
+	}
+
+	if (VIM_ISDIGIT(*cp))
+	    continue;
+	if (*cp == ',' && cp > var && *(cp - 1) != ',')
+	{
+	    ++valcount;
+	    continue;
+	}
+	EMSG(_(e_invarg));
+	return FALSE;
+    }
+
+    *array = (int *) alloc((unsigned) ((valcount + 1) * sizeof(int)));
+    (*array)[0] = valcount;
+
+    t = 1;
+    for (cp = var; *cp;)
+    {
+	(*array)[t++] = atoi((char *)cp);
+	while (*cp && *cp != ',')
+	    ++cp;
+	if (*cp)
+	    ++cp;
+    }
+
+    return TRUE;
+}
+
+/*
+ * Calculate the number of screen spaces a tab will occupy.
+ * If "vts" is set then the tab widths are taken from that array,
+ * otherwise the value of ts is used.
+ */
+    int
+tabstop_padding(colnr_T col, int ts_arg, int *vts)
+{
+    int		ts = ts_arg == 0 ? 8 : ts_arg;
+    int		tabcount;
+    colnr_T	tabcol = 0;
+    int		t;
+    int		padding = 0;
+
+    if (vts == NULL || vts[0] == 0)
+	return ts - (col % ts);
+
+    tabcount = vts[0];
+
+    for (t = 1; t <= tabcount; ++t)
+    {
+	tabcol += vts[t];
+	if (tabcol > col)
+	{
+	    padding = (int)(tabcol - col);
+	    break;
+	}
+    }
+    if (t > tabcount)
+	padding = vts[tabcount] - (int)((col - tabcol) % vts[tabcount]);
+
+    return padding;
+}
+
+/*
+ * Find the size of the tab that covers a particular column.
+ */
+    int
+tabstop_at(colnr_T col, int ts, int *vts)
+{
+    int		tabcount;
+    colnr_T	tabcol = 0;
+    int		t;
+    int		tab_size = 0;
+
+    if (vts == 0 || vts[0] == 0)
+	return ts;
+
+    tabcount = vts[0];
+    for (t = 1; t <= tabcount; ++t)
+    {
+	tabcol += vts[t];
+	if (tabcol > col)
+	{
+	    tab_size = vts[t];
+	    break;
+	}
+    }
+    if (t > tabcount)
+	tab_size = vts[tabcount];
+
+    return tab_size;
+}
+
+/*
+ * Find the column on which a tab starts.
+ */
+    colnr_T
+tabstop_start(colnr_T col, int ts, int *vts)
+{
+    int		tabcount;
+    colnr_T	tabcol = 0;
+    int		t;
+    int         excess;
+
+    if (vts == 0 || vts[0] == 0)
+	return (col / ts) * ts;
+
+    tabcount = vts[0];
+    for (t = 1; t <= tabcount; ++t)
+    {
+	tabcol += vts[t];
+	if (tabcol > col)
+	    return tabcol - vts[t];
+    }
+
+    excess = tabcol % vts[tabcount];
+    return excess + ((col - excess) / vts[tabcount]) * vts[tabcount];
+}
+
+/*
+ * Find the number of tabs and spaces necessary to get from one column
+ * to another.
+ */
+    void
+tabstop_fromto(
+	colnr_T start_col,
+	colnr_T end_col,
+	int	ts,
+	int	*vts,
+	int	*ntabs,
+	int	*nspcs)
+{
+    int		spaces = end_col - start_col;
+    colnr_T	tabcol = 0;
+    int		padding = 0;
+    int		tabcount;
+    int		t;
+
+    if (vts == 0 || vts[0] == 0)
+    {
+	int tabs = 0;
+	int initspc = ts - (start_col % ts);
+	if (spaces >= initspc)
+	{
+	    spaces -= initspc;
+	    tabs++;
+	}
+	tabs += spaces / ts;
+	spaces -= (spaces / ts) * ts;
+
+	*ntabs = tabs;
+	*nspcs = spaces;
+	return;
+    }
+
+    /* Find the padding needed to reach the next tabstop. */
+    tabcount = vts[0];
+    for (t = 1; t <= tabcount; ++t)
+    {
+	tabcol += vts[t];
+	if (tabcol > start_col)
+	{
+	    padding = (int)(tabcol - start_col);
+	    break;
+	}
+    }
+    if (t > tabcount)
+	padding = vts[tabcount] - (int)((start_col - tabcol) % vts[tabcount]);
+
+    /* If the space needed is less than the padding no tabs can be used. */
+    if (spaces < padding)
+    {
+	*ntabs = 0;
+	*nspcs = spaces;
+	return;
+    }
+
+    *ntabs = 1;
+    spaces -= padding;
+
+    /* At least one tab has been used. See if any more will fit. */
+    while (spaces != 0 && ++t <= tabcount)
+    {
+	padding = vts[t];
+	if (spaces < padding)
+	{
+	    *nspcs = spaces;
+	    return;
+	}
+	++*ntabs;
+	spaces -= padding;
+    }
+
+    *ntabs += spaces / vts[tabcount];
+    *nspcs =  spaces % vts[tabcount];
+}
+
+/*
+ * See if two tabstop arrays contain the same values.
+ */
+    int
+tabstop_eq(int *ts1, int *ts2)
+{
+    int		t;
+
+    if ((ts1 == 0 && ts2) || (ts1 && ts2 == 0))
+	return FALSE;
+    if (ts1 == ts2)
+	return TRUE;
+    if (ts1[0] != ts2[0])
+	return FALSE;
+
+    for (t = 1; t <= ts1[0]; ++t)
+	if (ts1[t] != ts2[t])
+	    return FALSE;
+
+    return TRUE;
+}
+
+/*
+ * Copy a tabstop array, allocating space for the new array.
+ */
+    int *
+tabstop_copy(int *oldts)
+{
+    int		*newts;
+    int		t;
+
+    if (oldts == 0)
+	return 0;
+
+    newts = (int *) alloc((unsigned) ((oldts[0] + 1) * sizeof(int)));
+    for (t = 0; t <= oldts[0]; ++t)
+	newts[t] = oldts[t];
+
+    return newts;
+}
+
+/*
+ * Return a count of the number of tabstops.
+ */
+    int
+tabstop_count(int *ts)
+{
+    return ts != NULL ? ts[0] : 0;
+}
+
+/*
+ * Return the first tabstop, or 8 if there are no tabstops defined.
+ */
+    int
+tabstop_first(int *ts)
+{
+    return ts != NULL ? ts[1] : 8;
+}
+
+#endif
+
 /*
  * Return the effective shiftwidth value for current buffer, using the
  * 'tabstop' value when 'shiftwidth' is zero.
diff --git a/src/option.h b/src/option.h
index 3aaaba7bf..5df7f2147 100644
--- a/src/option.h
+++ b/src/option.h
@@ -1114,6 +1114,10 @@ enum
 #ifdef FEAT_TERMINAL
     , BV_TWSL
 #endif
+#ifdef FEAT_VARTABS
+    , BV_VSTS
+    , BV_VTS
+#endif
     , BV_COUNT	    /* must be the last one */
 };
 
diff --git a/src/proto/misc1.pro b/src/proto/misc1.pro
index 0e1d22e60..58c3d3f49 100644
--- a/src/proto/misc1.pro
+++ b/src/proto/misc1.pro
@@ -3,6 +3,7 @@ int get_indent(void);
 int get_indent_lnum(linenr_T lnum);
 int get_indent_buf(buf_T *buf, linenr_T lnum);
 int get_indent_str(char_u *ptr, int ts, int list);
+int get_indent_str_vtab(char_u *ptr, int ts, int *vts, int list);
 int set_indent(int size, int flags);
 int get_number_indent(linenr_T lnum);
 int get_breakindent_win(win_T *wp, char_u *line);
diff --git a/src/proto/option.pro b/src/proto/option.pro
index 60a45e6d8..22c163d0f 100644
--- a/src/proto/option.pro
+++ b/src/proto/option.pro
@@ -60,6 +60,15 @@ int can_bs(int what);
 void save_file_ff(buf_T *buf);
 int file_ff_differs(buf_T *buf, int ignore_empty);
 int check_ff_value(char_u *p);
+int tabstop_set(char_u *var, int **array);
+int tabstop_padding(colnr_T col, int ts_arg, int *vts);
+int tabstop_at(colnr_T col, int ts, int *vts);
+colnr_T tabstop_start(colnr_T col, int ts, int *vts);
+void tabstop_fromto(colnr_T start_col, colnr_T end_col, int ts, int *vts, int *ntabs, int *nspcs);
+int tabstop_eq(int *ts1, int *ts2);
+int *tabstop_copy(int *oldts);
+int tabstop_count(int *ts);
+int tabstop_first(int *ts);
 long get_sw_value(buf_T *buf);
 long get_sts_value(void);
 void find_mps_values(int *initc, int *findc, int *backwards, int switchit);
diff --git a/src/screen.c b/src/screen.c
index b7b3e6714..b5b68e4df 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -4848,8 +4848,14 @@ win_line(
 			vcol_adjusted = vcol - MB_CHARLEN(p_sbr);
 #endif
 		    /* tab amount depends on current column */
+#ifdef FEAT_VARTABS
+		    tab_len = tabstop_padding(vcol_adjusted,
+					      wp->w_buffer->b_p_ts,
+					      wp->w_buffer->b_p_vts_array) - 1;
+#else
 		    tab_len = (int)wp->w_buffer->b_p_ts
-					- vcol_adjusted % (int)wp->w_buffer->b_p_ts - 1;
+			       - vcol_adjusted % (int)wp->w_buffer->b_p_ts - 1;
+#endif
 
 #ifdef FEAT_LINEBREAK
 		    if (!wp->w_p_lbr || !wp->w_p_list)
diff --git a/src/structs.h b/src/structs.h
index 56fcf674e..a2de2441e 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -2236,6 +2236,13 @@ struct file_buffer
     long	b_p_wm;		/* 'wrapmargin' */
     long	b_p_wm_nobin;	/* b_p_wm saved for binary mode */
     long	b_p_wm_nopaste;	/* b_p_wm saved for paste mode */
+#ifdef FEAT_VARTABS
+    char_u	*b_p_vsts;	/* 'varsofttabstop' */
+    int		*b_p_vsts_array;   /* 'varsofttabstop' in internal format */
+    char_u	*b_p_vsts_nopaste; /* b_p_vsts saved for paste mode */
+    char_u	*b_p_vts;	/* 'vartabstop' */
+    int		*b_p_vts_array;	/* 'vartabstop' in internal format */
+#endif
 #ifdef FEAT_KEYMAP
     char_u	*b_p_keymap;	/* 'keymap' */
 #endif
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index 6a0126b85..94e527ba2 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -147,8 +147,8 @@ NEW_TESTS = test_arabic.res \
 	    test_perl.res \
 	    test_plus_arg_edit.res \
 	    test_preview.res \
-	    test_prompt_buffer.res \
 	    test_profile.res \
+	    test_prompt_buffer.res \
 	    test_python2.res \
 	    test_python3.res \
 	    test_pyx2.res \
@@ -180,6 +180,7 @@ NEW_TESTS = test_arabic.res \
 	    test_undo.res \
 	    test_user_func.res \
 	    test_usercommands.res \
+	    test_vartabs.res \
 	    test_viminfo.res \
 	    test_vimscript.res \
 	    test_visual.res \
diff --git a/src/testdir/gen_opt_test.vim b/src/testdir/gen_opt_test.vim
index 9d12ea08d..a742153cd 100644
--- a/src/testdir/gen_opt_test.vim
+++ b/src/testdir/gen_opt_test.vim
@@ -136,6 +136,8 @@ let test_values = {
       \ 'toolbariconsize': [['', 'tiny', 'huge'], ['xxx']],
       \ 'ttymouse': [['', 'xterm'], ['xxx']],
       \ 'ttytype': [[], []],
+      \ 'varsofttabstop': [['8', '4,8,16,32'], ['xxx', '-1', '4,-1,20']],
+      \ 'vartabstop': [['8', '4,8,16,32'], ['xxx', '-1', '4,-1,20']],
       \ 'viewoptions': [['', 'cursor', 'unix,slash'], ['xxx']],
       \ 'viminfo': [['', '''50', '"30'], ['xxx']],
       \ 'virtualedit': [['', 'all', 'all,block'], ['xxx']],
diff --git a/src/testdir/test_breakindent.vim b/src/testdir/test_breakindent.vim
index 7deffbe45..ae05479ca 100644
--- a/src/testdir/test_breakindent.vim
+++ b/src/testdir/test_breakindent.vim
@@ -12,135 +12,267 @@ source view_util.vim
 
 let s:input ="\tabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP"
 
-function s:screen_lines(lnum, width) abort
+func s:screen_lines(lnum, width) abort
   return ScreenLines([a:lnum, a:lnum + 2], a:width)
-endfunction
+endfunc
 
-function! s:compare_lines(expect, actual)
+func s:compare_lines(expect, actual)
   call assert_equal(join(a:expect, "\n"), join(a:actual, "\n"))
-endfunction
+endfunc
 
-function s:test_windows(...)
+func s:test_windows(...)
   call NewWindow(10, 20)
   setl ts=4 sw=4 sts=4 breakindent
   put =s:input
   exe get(a:000, 0, '')
-endfunction
+endfunc
 
-function s:close_windows(...)
+func s:close_windows(...)
   call CloseWindow()
   exe get(a:000, 0, '')
-endfunction
+endfunc
 
-function Test_breakindent01()
+func Test_breakindent01()
   " simple breakindent test
   call s:test_windows('setl briopt=min:0')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "    qrst",
-\ "    GHIJ",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "    qrst",
+	\ "    GHIJ",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
 
-function Test_breakindent02()
+func Test_breakindent01_vartabs()
+  " like 01 but with vartabs feature
+  if !has("vartabs")
+    return
+  endif
+  call s:test_windows('setl briopt=min:0 vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "    qrst",
+	\ "    GHIJ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
+
+func Test_breakindent02()
   " simple breakindent test with showbreak set
   call s:test_windows('setl briopt=min:0 sbr=>>')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "    >>qr",
-\ "    >>EF",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "    >>qr",
+	\ "    >>EF",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set sbr=')
-endfunction
+endfunc
+
+func Test_breakindent02_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " simple breakindent test with showbreak set
+  call s:test_windows('setl briopt=min:0 sbr=>> vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "    >>qr",
+	\ "    >>EF",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set sbr= vts&')
+endfunc
 
-function Test_breakindent03()
+func Test_breakindent03()
   " simple breakindent test with showbreak set and briopt including sbr
   call s:test_windows('setl briopt=sbr,min:0 sbr=++')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "++  qrst",
-\ "++  GHIJ",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "++  qrst",
+	\ "++  GHIJ",
+	\ ]
   call s:compare_lines(expect, lines)
   " clean up
   call s:close_windows('set sbr=')
-endfunction
+endfunc
 
-function Test_breakindent04()
+func Test_breakindent03_vartabs()
+  " simple breakindent test with showbreak set and briopt including sbr
+  if !has("vartabs")
+    return
+  endif
+  call s:test_windows('setl briopt=sbr,min:0 sbr=++ vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "++  qrst",
+	\ "++  GHIJ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  " clean up
+  call s:close_windows('set sbr= vts&')
+endfunc
+
+func Test_breakindent04()
   " breakindent set with min width 18
   call s:test_windows('setl sbr= briopt=min:18')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "  qrstuv",
-\ "  IJKLMN",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "  qrstuv",
+	\ "  IJKLMN",
+	\ ]
   call s:compare_lines(expect, lines)
   " clean up
   call s:close_windows('set sbr=')
-endfunction
+endfunc
+
+func Test_breakindent04_vartabs()
+  " breakindent set with min width 18
+  if !has("vartabs")
+    return
+  endif
+  call s:test_windows('setl sbr= briopt=min:18 vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "  qrstuv",
+	\ "  IJKLMN",
+	\ ]
+  call s:compare_lines(expect, lines)
+  " clean up
+  call s:close_windows('set sbr= vts&')
+endfunc
 
-function Test_breakindent05()
+func Test_breakindent05()
   " breakindent set and shift by 2
   call s:test_windows('setl briopt=shift:2,min:0')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "      qr",
-\ "      EF",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "      qr",
+	\ "      EF",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
+
+func Test_breakindent05_vartabs()
+  " breakindent set and shift by 2
+  if !has("vartabs")
+    return
+  endif
+  call s:test_windows('setl briopt=shift:2,min:0 vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "      qr",
+	\ "      EF",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
 
-function Test_breakindent06()
+func Test_breakindent06()
   " breakindent set and shift by -1
   call s:test_windows('setl briopt=shift:-1,min:0')
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "    abcd",
-\ "   qrstu",
-\ "   HIJKL",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "   qrstu",
+	\ "   HIJKL",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
 
-function Test_breakindent07()
+func Test_breakindent06_vartabs()
+  " breakindent set and shift by -1
+  if !has("vartabs")
+    return
+  endif
+  call s:test_windows('setl briopt=shift:-1,min:0 vts=4')
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "    abcd",
+	\ "   qrstu",
+	\ "   HIJKL",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
+
+func Test_breakindent07()
   " breakindent set and shift by 1, Number  set sbr=? and briopt:sbr
   call s:test_windows('setl briopt=shift:1,sbr,min:0 nu sbr=? nuw=4 cpo+=n')
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2     ab",
-\ "?        m",
-\ "?        x",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "?        m",
+	\ "?        x",
+	\ ]
   call s:compare_lines(expect, lines)
   " clean up
   call s:close_windows('set sbr= cpo-=n')
-endfunction
+endfunc
 
-function Test_breakindent07a()
+func Test_breakindent07_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set and shift by 1, Number  set sbr=? and briopt:sbr
+  call s:test_windows('setl briopt=shift:1,sbr,min:0 nu sbr=? nuw=4 cpo+=n vts=4')
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "?        m",
+	\ "?        x",
+	\ ]
+  call s:compare_lines(expect, lines)
+  " clean up
+  call s:close_windows('set sbr= cpo-=n vts&')
+endfunc
+
+func Test_breakindent07a()
   " breakindent set and shift by 1, Number  set sbr=? and briopt:sbr
   call s:test_windows('setl briopt=shift:1,sbr,min:0 nu sbr=? nuw=4')
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2     ab",
-\ "    ?    m",
-\ "    ?    x",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "    ?    m",
+	\ "    ?    x",
+	\ ]
   call s:compare_lines(expect, lines)
   " clean up
   call s:close_windows('set sbr=')
-endfunction
+endfunc
+
+func Test_breakindent07a_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set and shift by 1, Number  set sbr=? and briopt:sbr
+  call s:test_windows('setl briopt=shift:1,sbr,min:0 nu sbr=? nuw=4 vts=4')
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "    ?    m",
+	\ "    ?    x",
+	\ ]
+  call s:compare_lines(expect, lines)
+  " clean up
+  call s:close_windows('set sbr= vts&')
+endfunc
 
-function Test_breakindent08()
+func Test_breakindent08()
   " breakindent set and shift by 1, Number and list set sbr=# and briopt:sbr
   call s:test_windows('setl briopt=shift:1,sbr,min:0 nu nuw=4 sbr=# list cpo+=n ts=4')
   " make sure, cache is invalidated!
@@ -148,43 +280,96 @@ function Test_breakindent08()
   redraw!
   set ts=4
   redraw!
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2 ^Iabcd",
-\ "#      opq",
-\ "#      BCD",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "#      opq",
+	\ "#      BCD",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set sbr= cpo-=n')
-endfunction
+endfunc
 
-function Test_breakindent08a()
+func Test_breakindent08_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set and shift by 1, Number and list set sbr=# and briopt:sbr
+  call s:test_windows('setl briopt=shift:1,sbr,min:0 nu nuw=4 sbr=# list cpo+=n ts=4 vts=4')
+  " make sure, cache is invalidated!
+  set ts=8
+  redraw!
+  set ts=4
+  redraw!
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "#      opq",
+	\ "#      BCD",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set sbr= cpo-=n vts&')
+endfunc
+
+func Test_breakindent08a()
   " breakindent set and shift by 1, Number and list set sbr=# and briopt:sbr
   call s:test_windows('setl briopt=shift:1,sbr,min:0 nu nuw=4 sbr=# list')
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2 ^Iabcd",
-\ "    #  opq",
-\ "    #  BCD",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "    #  opq",
+	\ "    #  BCD",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set sbr=')
-endfunction
+endfunc
+
+func Test_breakindent08a_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set and shift by 1, Number and list set sbr=# and briopt:sbr
+  call s:test_windows('setl briopt=shift:1,sbr,min:0 nu nuw=4 sbr=# list vts=4')
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "    #  opq",
+	\ "    #  BCD",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set sbr= vts&')
+endfunc
 
-function Test_breakindent09()
+func Test_breakindent09()
   " breakindent set and shift by 1, Number and list set sbr=#
   call s:test_windows('setl briopt=shift:1,min:0 nu nuw=4 sbr=# list')
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2 ^Iabcd",
-\ "       #op",
-\ "       #AB",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "       #op",
+	\ "       #AB",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set sbr=')
-endfunction
+endfunc
 
-function Test_breakindent10()
+func Test_breakindent09_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set and shift by 1, Number and list set sbr=#
+  call s:test_windows('setl briopt=shift:1,min:0 nu nuw=4 sbr=# list vts=4')
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2 ^Iabcd",
+	\ "       #op",
+	\ "       #AB",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set sbr= vts&')
+endfunc
+
+func Test_breakindent10()
   " breakindent set, Number set sbr=~
   call s:test_windows('setl cpo+=n sbr=~ nu nuw=4 nolist briopt=sbr,min:0')
   " make sure, cache is invalidated!
@@ -192,41 +377,91 @@ function Test_breakindent10()
   redraw!
   set ts=4
   redraw!
-  let lines=s:screen_lines(line('.'),10)
-  let expect=[
-\ "  2     ab",
-\ "~       mn",
-\ "~       yz",
-\ ]
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "~       mn",
+	\ "~       yz",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set sbr= cpo-=n')
-endfunction
+endfunc
 
-function Test_breakindent11()
+func Test_breakindent10_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " breakindent set, Number set sbr=~
+  call s:test_windows('setl cpo+=n sbr=~ nu nuw=4 nolist briopt=sbr,min:0 vts=4')
+  " make sure, cache is invalidated!
+  set ts=8
+  redraw!
+  set ts=4
+  redraw!
+  let lines = s:screen_lines(line('.'),10)
+  let expect = [
+	\ "  2     ab",
+	\ "~       mn",
+	\ "~       yz",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set sbr= cpo-=n vts&')
+endfunc
+
+func Test_breakindent11()
   " test strdisplaywidth()
   call s:test_windows('setl cpo-=n sbr=>> nu nuw=4 nolist briopt= ts=4')
-  let text=getline(2)
+  let text = getline(2)
   let width = strlen(text[1:])+indent(2)+strlen(&sbr)*3 " text wraps 3 times
   call assert_equal(width, strdisplaywidth(text))
   call s:close_windows('set sbr=')
-endfunction
+endfunc
 
-function Test_breakindent12()
+func Test_breakindent11_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " test strdisplaywidth()
+  call s:test_windows('setl cpo-=n sbr=>> nu nuw=4 nolist briopt= ts=4 vts=4')
+  let text = getline(2)
+  let width = strlen(text[1:])+indent(2)+strlen(&sbr)*3 " text wraps 3 times
+  call assert_equal(width, strdisplaywidth(text))
+  call s:close_windows('set sbr= vts&')
+endfunc
+
+func Test_breakindent12()
   " test breakindent with long indent
-  let s:input="\t\t\t\t\t{"
+  let s:input = "\t\t\t\t\t{"
   call s:test_windows('setl breakindent linebreak briopt=min:10 nu numberwidth=3 ts=4 list listchars=tab:>-')
-  let lines=s:screen_lines(2,16)
-  let expect=[
-\ " 2 >--->--->--->",
-\ "          ---{  ",
-\ "~               ",
-\ ]
+  let lines = s:screen_lines(2,16)
+  let expect = [
+	\ " 2 >--->--->--->",
+	\ "          ---{  ",
+	\ "~               ",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows('set nuw=4 listchars=')
-endfunction
+endfunc
 
-function Test_breakindent13()
-  let s:input=""
+func Test_breakindent12_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " test breakindent with long indent
+  let s:input = "\t\t\t\t\t{"
+  call s:test_windows('setl breakindent linebreak briopt=min:10 nu numberwidth=3 ts=4 list listchars=tab:>- vts=4')
+  let lines = s:screen_lines(2,16)
+  let expect = [
+	\ " 2 >--->--->--->",
+	\ "          ---{  ",
+	\ "~               ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set nuw=4 listchars= vts&')
+endfunc
+
+func Test_breakindent13()
+  let s:input = ""
   call s:test_windows('setl breakindent briopt=min:10 ts=8')
   vert resize 20
   call setline(1, ["    a\tb\tc\td\te", "    z   y       x       w       v"])
@@ -237,62 +472,146 @@ function Test_breakindent13()
   call assert_equal('d', @a)
   call assert_equal('w', @b)
   call s:close_windows()
-endfunction
+endfunc
+
+func Test_breakindent13_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  let s:input = ""
+  call s:test_windows('setl breakindent briopt=min:10 ts=8 vts=8')
+  vert resize 20
+  call setline(1, ["    a\tb\tc\td\te", "    z   y       x       w       v"])
+  1
+  norm! fbgj"ayl
+  2
+  norm! fygj"byl
+  call assert_equal('d', @a)
+  call assert_equal('w', @b)
+  call s:close_windows('set vts&')
+endfunc
 
-function Test_breakindent14()
-  let s:input=""
+func Test_breakindent14()
+  let s:input = ""
   call s:test_windows('setl breakindent briopt= ts=8')
   vert resize 30
   norm! 3a1234567890
   norm! a    abcde
   exec "norm! 0\<C-V>tex"
-  let lines=s:screen_lines(line('.'),8)
-  let expect=[
-\ "e       ",
-\ "~       ",
-\ "~       ",
-\ ]
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "e       ",
+	\ "~       ",
+	\ "~       ",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
 
-function Test_breakindent15()
-  let s:input=""
+func Test_breakindent14_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  let s:input = ""
+  call s:test_windows('setl breakindent briopt= ts=8 vts=8')
+  vert resize 30
+  norm! 3a1234567890
+  norm! a    abcde
+  exec "norm! 0\<C-V>tex"
+  let lines = s:screen_lines(line('.'),8)
+  let expect = [
+	\ "e       ",
+	\ "~       ",
+	\ "~       ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
+
+func Test_breakindent15()
+  let s:input = ""
   call s:test_windows('setl breakindent briopt= ts=8 sw=8')
   vert resize 30
   norm! 4a1234567890
   exe "normal! >>\<C-V>3f0x"
-  let lines=s:screen_lines(line('.'),20)
-  let expect=[
-\ "        1234567890  ",
-\ "~                   ",
-\ "~                   ",
-\ ]
+  let lines = s:screen_lines(line('.'),20)
+  let expect = [
+	\ "        1234567890  ",
+	\ "~                   ",
+	\ "~                   ",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
 
-function Test_breakindent16()
+func Test_breakindent15_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  let s:input = ""
+  call s:test_windows('setl breakindent briopt= ts=8 sw=8 vts=8')
+  vert resize 30
+  norm! 4a1234567890
+  exe "normal! >>\<C-V>3f0x"
+  let lines = s:screen_lines(line('.'),20)
+  let expect = [
+	\ "        1234567890  ",
+	\ "~                   ",
+	\ "~                   ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
+
+func Test_breakindent16()
   " Check that overlong lines are indented correctly.
-  let s:input=""
+  let s:input = ""
   call s:test_windows('setl breakindent briopt=min:0 ts=4')
   call setline(1, "\t".repeat("1234567890", 10))
   resize 6
   norm! 1gg$
   redraw!
-  let lines=s:screen_lines(1,10)
-  let expect=[
-\ "    789012",
-\ "    345678",
-\ "    901234",
-\ ]
-  call s:compare_lines(expect, lines)
-  let lines=s:screen_lines(4,10)
-  let expect=[
-\ "    567890",
-\ "    123456",
-\ "    7890  ",
-\ ]
+  let lines = s:screen_lines(1,10)
+  let expect = [
+	\ "    789012",
+	\ "    345678",
+	\ "    901234",
+	\ ]
+  call s:compare_lines(expect, lines)
+  let lines = s:screen_lines(4,10)
+  let expect = [
+	\ "    567890",
+	\ "    123456",
+	\ "    7890  ",
+	\ ]
   call s:compare_lines(expect, lines)
   call s:close_windows()
-endfunction
+endfunc
+
+func Test_breakindent16_vartabs()
+  if !has("vartabs")
+    return
+  endif
+  " Check that overlong lines are indented correctly.
+  let s:input = ""
+  call s:test_windows('setl breakindent briopt=min:0 ts=4 vts=4')
+  call setline(1, "\t".repeat("1234567890", 10))
+  resize 6
+  norm! 1gg$
+  redraw!
+  let lines = s:screen_lines(1,10)
+  let expect = [
+	\ "    789012",
+	\ "    345678",
+	\ "    901234",
+	\ ]
+  call s:compare_lines(expect, lines)
+  let lines = s:screen_lines(4,10)
+  let expect = [
+	\ "    567890",
+	\ "    123456",
+	\ "    7890  ",
+	\ ]
+  call s:compare_lines(expect, lines)
+  call s:close_windows('set vts&')
+endfunc
diff --git a/src/testdir/test_vartabs.vim b/src/testdir/test_vartabs.vim
new file mode 100644
index 000000000..85914f6bc
--- /dev/null
+++ b/src/testdir/test_vartabs.vim
@@ -0,0 +1,257 @@
+" Test for variable tabstops
+
+if !has("vartabs")
+  finish
+endif
+
+func! Test_vartabs()
+  new
+  %d
+
+  " Test normal operation of tabstops ...
+  set ts=4
+  call setline(1, join(split('aaaaa', '\zs'), "\t"))
+  retab 8
+  let expect = "a   a\<tab>a   a\<tab>a"
+  call assert_equal(expect, getline(1))
+
+  " ... and softtabstops
+  set ts=8 sts=6
+  exe "norm! Sb\<tab>b\<tab>b\<tab>b\<tab>b"
+  let expect = "b     b\<tab>    b\<tab>  b\<tab>b"
+  call assert_equal(expect, getline(1))
+
+  " Test variable tabstops.
+  set sts=0 vts=4,8,4,8
+  exe "norm! Sc\<tab>c\<tab>c\<tab>c\<tab>c\<tab>c"
+  retab 8
+  let expect = "c   c\<tab>    c\<tab>c\<tab>c\<tab>c"
+  call assert_equal(expect, getline(1))
+
+  set et vts=4,8,4,8
+  exe "norm! Sd\<tab>d\<tab>d\<tab>d\<tab>d\<tab>d"
+  let expect = "d   d       d   d       d       d"
+  call assert_equal(expect, getline(1))
+
+  " Changing ts should have no effect if vts is in use.
+  call cursor(1, 1)
+  set ts=6
+  exe "norm! Se\<tab>e\<tab>e\<tab>e\<tab>e\<tab>e"
+  let expect = "e   e       e   e       e       e"
+  call assert_equal(expect, getline(1))
+
+  " Clearing vts should revert to using ts.
+  set vts=
+  exe "norm! Sf\<tab>f\<tab>f\<tab>f\<tab>f\<tab>f"
+  let expect = "f     f     f     f     f     f"
+  call assert_equal(expect, getline(1))
+
+  " Test variable softtabstops.
+  set noet ts=8 vsts=12,2,6
+  exe "norm! Sg\<tab>g\<tab>g\<tab>g\<tab>g\<tab>g"
+  let expect = "g\<tab>    g g\<tab>    g\<tab>  g\<tab>g"
+  call assert_equal(expect, getline(1))
+
+  " Variable tabstops and softtabstops combined.
+  set vsts=6,12,8 vts=4,6,8
+  exe "norm! Sh\<tab>h\<tab>h\<tab>h\<tab>h"
+  let expect = "h\<tab>  h\<tab>\<tab>h\<tab>h\<tab>h"
+  call assert_equal(expect, getline(1))
+
+  " Retab with a single value, not using vts.
+  set ts=8 sts=0 vts= vsts=
+  exe "norm! Si\<tab>i\<tab>i\<tab>i\<tab>i"
+  retab 4
+  let expect = "i\<tab>\<tab>i\<tab>\<tab>i\<tab>\<tab>i\<tab>\<tab>i"
+  call assert_equal(expect, getline(1))
+
+  " Retab with a single value, using vts.
+  set ts=8 sts=0 vts=6 vsts=
+  exe "norm! Sj\<tab>j\<tab>j\<tab>j\<tab>j"
+  retab 4
+  let expect = "j\<tab>  j\<tab>\<tab>j\<tab>  j\<tab>\<tab>j"
+  call assert_equal(expect, getline(1))
+
+  " Retab with multiple values, not using vts.
+  set ts=6 sts=0 vts= vsts=
+  exe "norm! Sk\<tab>k\<tab>k\<tab>k\<tab>k\<tab>k"
+  retab 4,8
+  let expect = "k\<tab>  k\<tab>k     k\<tab>    k\<tab>  k"
+  call assert_equal(expect, getline(1))
+
+  " Retab with multiple values, using vts.
+  set ts=8 sts=0 vts=6 vsts=
+  exe "norm! Sl\<tab>l\<tab>l\<tab>l\<tab>l\<tab>l"
+  retab 4,8
+  let expect = "l\<tab>  l\<tab>l     l\<tab>    l\<tab>  l"
+  call assert_equal(expect, getline(1))
+
+  " Check that global and local values are set.
+  set ts=4 vts=6 sts=8 vsts=10
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  new
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  bwipeout!
+
+  " Check that local values only are set.
+  setlocal ts=5 vts=7 sts=9 vsts=11
+  call assert_equal(&ts, 5)
+  call assert_equal(&vts, '7')
+  call assert_equal(&sts, 9)
+  call assert_equal(&vsts, '11')
+  new
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  bwipeout!
+
+  " Check that global values only are set.
+  setglobal ts=6 vts=8 sts=10 vsts=12
+  call assert_equal(&ts, 5)
+  call assert_equal(&vts, '7')
+  call assert_equal(&sts, 9)
+  call assert_equal(&vsts, '11')
+  new
+  call assert_equal(&ts, 6)
+  call assert_equal(&vts, '8')
+  call assert_equal(&sts, 10)
+  call assert_equal(&vsts, '12')
+  bwipeout!
+
+  set ts& vts& sts& vsts& et&
+  bwipeout!
+endfunc
+
+func! Test_vartabs_breakindent()
+  if !exists("+breakindent")
+    return
+  endif
+  new
+  %d
+
+  " Test normal operation of tabstops ...
+  set ts=4
+  call setline(1, join(split('aaaaa', '\zs'), "\t"))
+  retab 8
+  let expect = "a   a\<tab>a   a\<tab>a"
+  call assert_equal(expect, getline(1))
+
+  " ... and softtabstops
+  set ts=8 sts=6
+  exe "norm! Sb\<tab>b\<tab>b\<tab>b\<tab>b"
+  let expect = "b     b\<tab>    b\<tab>  b\<tab>b"
+  call assert_equal(expect, getline(1))
+
+  " Test variable tabstops.
+  set sts=0 vts=4,8,4,8
+  exe "norm! Sc\<tab>c\<tab>c\<tab>c\<tab>c\<tab>c"
+  retab 8
+  let expect = "c   c\<tab>    c\<tab>c\<tab>c\<tab>c"
+  call assert_equal(expect, getline(1))
+
+  set et vts=4,8,4,8
+  exe "norm! Sd\<tab>d\<tab>d\<tab>d\<tab>d\<tab>d"
+  let expect = "d   d       d   d       d       d"
+  call assert_equal(expect, getline(1))
+
+  " Changing ts should have no effect if vts is in use.
+  call cursor(1, 1)
+  set ts=6
+  exe "norm! Se\<tab>e\<tab>e\<tab>e\<tab>e\<tab>e"
+  let expect = "e   e       e   e       e       e"
+  call assert_equal(expect, getline(1))
+
+  " Clearing vts should revert to using ts.
+  set vts=
+  exe "norm! Sf\<tab>f\<tab>f\<tab>f\<tab>f\<tab>f"
+  let expect = "f     f     f     f     f     f"
+  call assert_equal(expect, getline(1))
+
+  " Test variable softtabstops.
+  set noet ts=8 vsts=12,2,6
+  exe "norm! Sg\<tab>g\<tab>g\<tab>g\<tab>g\<tab>g"
+  let expect = "g\<tab>    g g\<tab>    g\<tab>  g\<tab>g"
+  call assert_equal(expect, getline(1))
+
+  " Variable tabstops and softtabstops combined.
+  set vsts=6,12,8 vts=4,6,8
+  exe "norm! Sh\<tab>h\<tab>h\<tab>h\<tab>h"
+  let expect = "h\<tab>  h\<tab>\<tab>h\<tab>h\<tab>h"
+  call assert_equal(expect, getline(1))
+
+  " Retab with a single value, not using vts.
+  set ts=8 sts=0 vts= vsts=
+  exe "norm! Si\<tab>i\<tab>i\<tab>i\<tab>i"
+  retab 4
+  let expect = "i\<tab>\<tab>i\<tab>\<tab>i\<tab>\<tab>i\<tab>\<tab>i"
+  call assert_equal(expect, getline(1))
+
+  " Retab with a single value, using vts.
+  set ts=8 sts=0 vts=6 vsts=
+  exe "norm! Sj\<tab>j\<tab>j\<tab>j\<tab>j"
+  retab 4
+  let expect = "j\<tab>  j\<tab>\<tab>j\<tab>  j\<tab>\<tab>j"
+  call assert_equal(expect, getline(1))
+
+  " Retab with multiple values, not using vts.
+  set ts=6 sts=0 vts= vsts=
+  exe "norm! Sk\<tab>k\<tab>k\<tab>k\<tab>k\<tab>k"
+  retab 4,8
+  let expect = "k\<tab>  k\<tab>k     k\<tab>    k\<tab>  k"
+  call assert_equal(expect, getline(1))
+
+  " Retab with multiple values, using vts.
+  set ts=8 sts=0 vts=6 vsts=
+  exe "norm! Sl\<tab>l\<tab>l\<tab>l\<tab>l\<tab>l"
+  retab 4,8
+  let expect = "l\<tab>  l\<tab>l     l\<tab>    l\<tab>  l"
+  call assert_equal(expect, getline(1))
+
+  " Check that global and local values are set.
+  set ts=4 vts=6 sts=8 vsts=10
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  new
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  bwipeout!
+
+  " Check that local values only are set.
+  setlocal ts=5 vts=7 sts=9 vsts=11
+  call assert_equal(&ts, 5)
+  call assert_equal(&vts, '7')
+  call assert_equal(&sts, 9)
+  call assert_equal(&vsts, '11')
+  new
+  call assert_equal(&ts, 4)
+  call assert_equal(&vts, '6')
+  call assert_equal(&sts, 8)
+  call assert_equal(&vsts, '10')
+  bwipeout!
+
+  " Check that global values only are set.
+  setglobal ts=6 vts=8 sts=10 vsts=12
+  call assert_equal(&ts, 5)
+  call assert_equal(&vts, '7')
+  call assert_equal(&sts, 9)
+  call assert_equal(&vsts, '11')
+  new
+  call assert_equal(&ts, 6)
+  call assert_equal(&vts, '8')
+  call assert_equal(&sts, 10)
+  call assert_equal(&vsts, '12')
+  bwipeout!
+
+  bwipeout!
+endfunc
diff --git a/src/version.c b/src/version.c
index e2ccc112e..85b679710 100644
--- a/src/version.c
+++ b/src/version.c
@@ -677,6 +677,11 @@ static char *(features[]) =
 #else
 	"-user_commands",
 #endif
+#ifdef FEAT_VARTABS
+	"+vartabs",
+#else
+	"-vartabs",
+#endif
 	"+vertsplit",
 #ifdef FEAT_VIRTUALEDIT
 	"+virtualedit",
@@ -779,6 +784,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    105,
+/**/
     104,
 /**/
     103,
diff --git a/src/workshop.c b/src/workshop.c
index 143f77914..cb6ba3e59 100644
--- a/src/workshop.c
+++ b/src/workshop.c
@@ -49,7 +49,11 @@ static void	 load_window(char *, int lnum);
 static void	 warp_to_pc(int);
 #ifdef FEAT_BEVAL_GUI
 void		 workshop_beval_cb(BalloonEval *, int);
+# ifdef FEAT_VARTABS
+static int	 computeIndex(int, char_u *, int, int *);
+# else
 static int	 computeIndex(int, char_u *, int);
+# endif
 #endif
 static char	*fixAccelText(char *);
 static void	 addMenu(char *, char *, char *);
@@ -1534,7 +1538,11 @@ workshop_beval_cb(
 	     * a column number. Compute the index from col. Also set
 	     * line to 0 because thats what dbx expects.
 	     */
+#ifdef FEAT_VARTABS
+	    idx = computeIndex(col, text, beval->ts, beval->vts);
+#else
 	    idx = computeIndex(col, text, beval->ts);
+#endif
 	    if (idx > 0)
 	    {
 		lnum = 0;
@@ -1569,7 +1577,11 @@ workshop_beval_cb(
 computeIndex(
 	int		 wantedCol,
 	char_u		*line,
-	int		 ts)
+	int		 ts
+#ifdef FEAT_VARTABS
+	int		*vts
+#else
+	)
 {
     int		 col = 0;
     int		 idx = 0;
@@ -1577,7 +1589,11 @@ computeIndex(
     while (line[idx])
     {
 	if (line[idx] == '\t')
+#ifdef FEAT_VARTABS
+	    col += tabstop_padding(col, ts, vts);
+#else
 	    col += ts - (col % ts);
+#endif
 	else
 	    col++;
 	idx++;