Bug fix: add enabled/disabled guards to notifiers.

Also handle the case when user disables notifiers after the first run.
This doesn't work for signs though, since it causes an ugly flicker in
the common case.

plugin/syntastic/balloons.vim

@@ -21,13 +21,15 @@ function! g:SyntasticBalloonsNotifier.New()
 endfunction
 
 function! g:SyntasticBalloonsNotifier.enabled()
-    return exists('b:syntastic_enable_balloons') ? b:syntastic_enable_balloons : g:syntastic_enable_balloons
+    return
+        \ has('balloon_eval') &&
+        \ (exists('b:syntastic_enable_balloons') ? b:syntastic_enable_balloons : g:syntastic_enable_balloons)
 endfunction
 
 " Update the error balloons
 function! g:SyntasticBalloonsNotifier.refresh(loclist)
     let b:syntastic_balloons = {}
-    if a:loclist.hasErrorsOrWarningsToDisplay()
+    if self.enabled() && a:loclist.hasErrorsOrWarningsToDisplay()
         let buf = bufnr('')
         let issues = filter(a:loclist.filteredRaw(), 'v:val["bufnr"] == buf')
         if !empty(issues)
@@ -45,7 +47,9 @@ endfunction
 
 " Reset the error balloons
 function! g:SyntasticBalloonsNotifier.reset(loclist)
+    if has('balloon_eval')
         set nobeval
+    endif
 endfunction
 
 " Private functions {{{1

plugin/syntastic/cursor.vim

@@ -16,9 +16,12 @@ function! g:SyntasticCursorNotifier.New()
     return newObj
 endfunction
 
+function! g:SyntasticCursorNotifier.enabled()
+    return exists('b:syntastic_echo_current_error') ? b:syntastic_echo_current_error : g:syntastic_echo_current_error
+endfunction
+
 function! g:SyntasticCursorNotifier.refresh(loclist)
-    let enabled = exists('b:syntastic_echo_current_error') ? b:syntastic_echo_current_error : g:syntastic_echo_current_error
+    if self.enabled() && a:loclist.hasErrorsOrWarningsToDisplay()
-    if enabled && a:loclist.hasErrorsOrWarningsToDisplay()
         let b:syntastic_messages = copy(a:loclist.messages(bufnr('')))
         let b:oldLine = -1
         autocmd! syntastic CursorMoved

plugin/syntastic/highlighting.vim

@@ -3,15 +3,13 @@ if exists("g:loaded_syntastic_notifier_highlighting")
 endif
 let g:loaded_syntastic_notifier_highlighting = 1
 
+" Highlighting requires getmatches introduced in 7.1.040
+let s:has_highlighting = v:version > 701 || (v:version == 701 && has('patch040'))
+
 if !exists("g:syntastic_enable_highlighting")
     let g:syntastic_enable_highlighting = 1
 endif
 
-" Highlighting requires getmatches introduced in 7.1.040
-if v:version < 701 || (v:version == 701 && !has('patch040'))
-    let g:syntastic_enable_highlighting = 0
-endif
-
 let g:SyntasticHighlightingNotifier = {}
 
 " Public methods {{{1
@@ -22,11 +20,14 @@ function! g:SyntasticHighlightingNotifier.New()
 endfunction
 
 function! g:SyntasticHighlightingNotifier.enabled()
-    return exists('b:syntastic_enable_highlighting') ? b:syntastic_enable_highlighting : g:syntastic_enable_highlighting
+    return
+        \ s:has_highlighting &&
+        \ (exists('b:syntastic_enable_highlighting') ? b:syntastic_enable_highlighting : g:syntastic_enable_highlighting)
 endfunction
 
 " Sets error highlights in the cuirrent window
 function! g:SyntasticHighlightingNotifier.refresh(loclist)
+    if self.enabled()
         call self.reset(a:loclist)
         let buf = bufnr('')
         let issues = filter(a:loclist.filteredRaw(), 'v:val["bufnr"] == buf')
@@ -48,15 +49,18 @@ function! g:SyntasticHighlightingNotifier.refresh(loclist)
                 call matchadd(group, '\%' . item['lnum'] . 'l\%' . lcol . coltype)
             endif
         endfor
+    endif
 endfunction
 
 " Remove all error highlights from the window
 function! g:SyntasticHighlightingNotifier.reset(loclist)
+    if s:has_highlighting
         for match in getmatches()
             if stridx(match['group'], 'Syntastic') == 0
                 call matchdelete(match['id'])
             endif
         endfor
+    endif
 endfunction
 
 " vim: set sw=4 sts=4 et fdm=marker:

plugin/syntastic/notifiers.vim

@@ -30,7 +30,11 @@ endfunction
 function! g:SyntasticNotifiers.reset(loclist)
     for type in self._enabled_types
         let class = substitute(type, '.*', 'Syntastic\u&Notifier', '')
-        if has_key(g:{class}, 'reset') && (!has_key(g:{class}, 'enabled') || self._notifier[type].enabled())
+
+        " reset notifiers regardless if they are enabled or not, since
+        " the user might have disabled them since the last refresh();
+        " notifiers MUST be prepared to deal with reset() when disabled
+        if has_key(g:{class}, 'reset')
             call self._notifier[type].reset(a:loclist)
         endif
     endfor

plugin/syntastic/signs.vim

@@ -23,10 +23,6 @@ if !exists("g:syntastic_style_warning_symbol")
     let g:syntastic_style_warning_symbol = 'S>'
 endif
 
-if !has('signs')
-    let g:syntastic_enable_signs = 0
-endif
-
 
 " start counting sign ids at 5000, start here to hopefully avoid conflicting
 " with any other code that places signs (not sure if this precaution is
@@ -52,13 +48,16 @@ function! g:SyntasticSignsNotifier.New()
 endfunction
 
 function! g:SyntasticSignsNotifier.enabled()
-    return exists('b:syntastic_enable_signs') ? b:syntastic_enable_signs : g:syntastic_enable_signs
+    return
+        \ has('signs') &&
+        \ exists('b:syntastic_enable_signs') ? b:syntastic_enable_signs : g:syntastic_enable_signs
 endfunction
 
-" Update the error signs
 function! g:SyntasticSignsNotifier.refresh(loclist)
     let old_signs = copy(self._bufSignIds())
+    if self.enabled()
         call self._signErrors(a:loclist)
+    endif
     call self._removeSigns(old_signs)
     let s:first_sign_id = s:next_sign_id
 endfunction
@@ -125,10 +124,12 @@ endfunction
 
 " Remove the signs with the given ids from this buffer
 function! g:SyntasticSignsNotifier._removeSigns(ids)
+    if has('signs')
         for i in a:ids
             exec "sign unplace " . i
             call remove(self._bufSignIds(), index(self._bufSignIds(), i))
         endfor
+    endif
 endfunction
 
 " Get all the ids of the SyntaxError signs in the buffer