Minor cleanup.

Warning signs should not overwrite error ones.
Use buffers instead of file names when placing signs.
Other minor changes.

plugin/syntastic.vim

@@ -101,17 +101,15 @@ function! s:UpdateErrors(auto_invoked, ...)
         endif
     end
 
-    call s:notifiers.refresh(g:SyntasticLoclist.Current())
-
     let loclist = g:SyntasticLoclist.Current()
-    if g:syntastic_always_populate_loc_list && loclist.hasErrorsOrWarningsToDisplay()
-        call setloclist(0, loclist.filteredRaw())
-    endif
+    call s:notifiers.refresh(loclist)
 
-    if g:syntastic_auto_jump && loclist.hasErrorsOrWarningsToDisplay()
+    if (g:syntastic_always_populate_loc_list || g:syntastic_auto_jump) && loclist.hasErrorsOrWarningsToDisplay()
         call setloclist(0, loclist.filteredRaw())
+        if g:syntastic_auto_jump
             silent! ll
         endif
+    endif
 endfunction
 
 "clear the loc list for the buffer

plugin/syntastic/cursor.vim

@@ -31,6 +31,7 @@ function! g:SyntasticCursorNotifier.refresh(loclist)
 endfunction
 
 function! g:SyntasticCursorNotifier.reset(loclist)
+    unlet b:syntastic_messages
     let b:oldLine = -1
 endfunction
 

plugin/syntastic/loclist.vim

@@ -47,6 +47,10 @@ function! g:SyntasticLoclist.filteredRaw()
     return copy(self._quietWarnings ? self.errors() : self._rawLoclist)
 endfunction
 
+function! g:SyntasticLoclist.quietWarnings()
+    return self._quietWarnings
+endfunction
+
 function! g:SyntasticLoclist.isEmpty()
     return empty(self._rawLoclist)
 endfunction

plugin/syntastic/signer.vim

@@ -103,24 +103,18 @@ function! g:SyntasticSignsNotifier._signErrors(loclist)
     let loclist = a:loclist
     if loclist.hasErrorsOrWarningsToDisplay()
 
-        let lfilter = {'bufnr': bufnr('')}
-        if g:syntastic_quiet_warnings
-            let lfilter['type'] = 'E'
-        endif
-        let errors = loclist.filter(lfilter)
+        let buf = bufnr('')
+        let errors = loclist.quietWarnings() ? [] : loclist.warnings()
+        call extend(errors, loclist.errors())
+        call filter(errors, 'v:val["bufnr"] == buf')
+
         for i in errors
-            let sign_severity = 'Error'
-            let sign_subtype = ''
-            if has_key(i,'subtype')
-                let sign_subtype = i['subtype']
-            endif
-            if i['type'] ==? 'w'
-                let sign_severity = 'Warning'
-            endif
+            let sign_severity = i['type'] ==? 'w' ? 'Warning' : 'Error'
+            let sign_subtype = has_key(i,'subtype') ? i['subtype'] : ''
             let sign_type = 'Syntastic' . sign_subtype . sign_severity
 
             if !self._warningMasksError(i, errors)
-                exec "sign place ". s:next_sign_id ." line=". i['lnum'] ." name=". sign_type ." file=". expand("%:p")
+                exec "sign place " . s:next_sign_id . " line=" . i['lnum'] . " name=" . sign_type . " buffer=" . i['bufnr']
                 call add(self._bufSignIds(), s:next_sign_id)
                 let s:next_sign_id += 1
             endif