* configure.in: check for the vsnprintf function and stdarg.h

header.

* src/main.c (xvsprintf): Cleaned up to call vsnprintf only in one
place. wrap the vsnprintf call with va_copy (or __va_copy) and
va_end.

3 files changed, 40 insertions, 21 deletions

diff --git a/ChangeLog b/ChangeLog
index 083c3d8..b847444 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2002-01-26  shawn  <sabetts@vcn.bc.ca>
 
+	* configure.in: check for the vsnprintf function and stdarg.h
+	header.
+
+	* src/main.c (xvsprintf): Cleaned up to call vsnprintf only in one
+	place. wrap the vsnprintf call with va_copy (or __va_copy) and
+	va_end.
+
 	* src/list.c (format_window_name): If res_class or res_name are
 	NULL use "None" instead.
 
diff --git a/configure.in b/configure.in
index 6e3d8f6..c2f9629 100644
--- a/configure.in
+++ b/configure.in
@@ -17,7 +17,7 @@ dnl You should have received a copy of the GNU General Public License
 dnl along with this program; if not, write to the Free Software
 dnl Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 dnl
-dnl $Id: configure.in,v 1.24 2002/01/08 19:13:06 algernon Exp $
+dnl $Id: configure.in,v 1.25 2002/01/27 00:57:19 sabetts Exp $
 
 AC_INIT(src/main.c)
 AM_INIT_AUTOMAKE(ratpoison, 1.0.1-cvs)
@@ -69,12 +69,13 @@ AC_CHECK_LIB(X11, XOpenDisplay,,
 dnl Checks for header files.
 AC_HEADER_STDC
 AC_HEADER_SYS_WAIT
-AC_CHECK_HEADERS(unistd.h)
+AC_CHECK_HEADERS(unistd.h stdarg.h)
 
 dnl Checks for typedefs, structures, and compiler characteristics.
 
 dnl Checks for library functions.
-AC_CHECK_FUNCS(getopt getopt_long setsid setpgid setpgrp setenv unsetenv)
+AC_CHECK_FUNCS(getopt getopt_long setsid setpgid setpgrp setenv unsetenv vsnprintf )
+
 AC_TYPE_SIGNAL
 
 AC_OUTPUT(Makefile doc/Makefile src/Makefile contrib/Makefile)
diff --git a/src/main.c b/src/main.c
index 2ba8ecf..ae698c5 100644
--- a/src/main.c
+++ b/src/main.c
@@ -130,32 +130,43 @@ xvsprintf (char *fmt, va_list ap)
 {
   int size, nchars;
   char *buffer;
+  va_list ap_copy;
 
   /* A resonable starting value. */
   size = strlen (fmt) + 1;
   buffer = (char *)xmalloc (size);
 
-  nchars = vsnprintf (buffer, size, fmt, ap);
-
-  /* From the GNU Libc manual: In versions of the GNU C library prior
-     to 2.1 the return value is the number of characters stored, not
-     including the terminating null; unless there was not enough space
-     in S to store the result in which case `-1' is returned. */
-  if (nchars == -1)
-    {
-      do
-	{
-	  size *= 2;
-	  buffer = (char *)xrealloc (buffer, size);
-	} while (vsnprintf (buffer, size, fmt, ap) == -1);
-    }
-  else if (nchars >= size)
+  while (1)
     {
-      buffer = (char *)xrealloc (buffer, nchars + 1);
-      vsnprintf (buffer, nchars + 1, fmt, ap);
+#if defined(va_copy)
+      va_copy (ap_copy, ap);
+#elif defined(__va_copy)
+      __va_copy (ap_copy, ap);
+#else
+      /* If there is no copy macro then this MAY work. On some systems
+	 this could fail because va_list is a pointer so assigning one
+	 to the other as below wouldn't make a copy of the data, but
+	 just the pointer to the data. */
+      ap_copy = ap;
+#endif
+      nchars = vsnprintf (buffer, size, fmt, ap_copy);
+#if defined(va_copy) || defined(__va_copy)
+      va_end (ap_copy);
+#endif
+
+      if (nchars > -1 && nchars < size)
+	return buffer;
+      else if (nchars > -1)
+	size = nchars + 1;
+      else
+	size *= 2;
+
+      /* Resize the buffer and try again. */
+      buffer = (char *)xrealloc (buffer, size);
     }
 
-  return buffer;
+  /* Never gets here. */
+  return NULL;
 }
 
 /* Return a new string based on fmt. */