#338 Try and stop ALE from throwing ALEs when run from a sandbox

4 files changed, 40 insertions, 6 deletions

diff --git a/autoload/ale.vim b/autoload/ale.vim
index a5251f64..c81a57a6 100644
--- a/autoload/ale.vim
+++ b/autoload/ale.vim
@@ -4,9 +4,17 @@
 
 let s:lint_timer = -1
 
+" A function for checking various conditions whereby ALE just shouldn't
+" attempt to do anything, say if particular buffer types are open in Vim.
+function! ale#ShouldDoNothing() abort
+    " Do nothing for blacklisted files
+    " OR if ALE is running in the sandbox
+    return index(g:ale_filetype_blacklist, &filetype) >= 0
+    \   || ale#util#InSandbox()
+endfunction
+
 function! ale#Queue(delay) abort
-    " Do nothing for blacklisted files.
-    if index(g:ale_filetype_blacklist, &filetype) >= 0
+    if ale#ShouldDoNothing()
         return
     endif
 
@@ -29,8 +37,7 @@ function! ale#Queue(delay) abort
 endfunction
 
 function! ale#Lint(...) abort
-    " Do nothing for blacklisted files.
-    if index(g:ale_filetype_blacklist, &filetype) >= 0
+    if ale#ShouldDoNothing()
         return
     endif
 
diff --git a/autoload/ale/cursor.vim b/autoload/ale/cursor.vim
index 864f6f28..9aaa8e91 100644
--- a/autoload/ale/cursor.vim
+++ b/autoload/ale/cursor.vim
@@ -73,8 +73,7 @@ let s:cursor_timer = -1
 let s:last_pos = [0, 0, 0]
 
 function! ale#cursor#EchoCursorWarningWithDelay() abort
-    " Do nothing for blacklisted files.
-    if index(g:ale_filetype_blacklist, &filetype) >= 0
+    if ale#ShouldDoNothing()
         return
     endif
 
diff --git a/autoload/ale/engine.vim b/autoload/ale/engine.vim
index 5337fc2d..d816a96b 100644
--- a/autoload/ale/engine.vim
+++ b/autoload/ale/engine.vim
@@ -155,6 +155,12 @@ function! ale#engine#RemoveManagedFiles(buffer) abort
         return
     endif
 
+    " We can't delete anything in a sandbox, so wait until we escape from
+    " it to delete temporary files and directories.
+    if ale#util#InSandbox()
+        return
+    endif
+
     " Delete files with a call akin to a plan `rm` command.
     for l:filename in g:ale_buffer_info[a:buffer].temporary_file_list
         call delete(l:filename)
@@ -195,6 +201,12 @@ function! s:HandleExit(job) abort
     " which just closed.
     call s:StopPreviousJobs(l:buffer, l:linter)
 
+    " Stop here if we land in the handle for a job completing if we're in
+    " a sandbox.
+    if ale#util#InSandbox()
+        return
+    endif
+
     if l:next_chain_index < len(get(l:linter, 'command_chain', []))
         call s:InvokeChain(l:buffer, l:linter, l:next_chain_index, l:output)
         return
diff --git a/autoload/ale/util.vim b/autoload/ale/util.vim
index 6367489c..bf00051a 100644
--- a/autoload/ale/util.vim
+++ b/autoload/ale/util.vim
@@ -118,3 +118,19 @@ function! ale#util#BinarySearch(loclist, line, column) abort
         endif
     endwhile
 endfunction
+
+" A function for testing if a function is running inside a sandbox.
+" See :help sandbox
+function! ale#util#InSandbox() abort
+    try
+        call setbufvar('%', '', '')
+    catch /^Vim\%((\a\+)\)\=:E48/
+        " E48 is the sandbox error.
+        return 1
+    catch
+        " If we're not in a sandbox, we'll get another error about an
+        " invalid buffer variable name.
+    endtry
+
+    return 0
+endfunction