Prevent potential regressions

References #95.

autoload/sy.vim

@@ -96,7 +96,8 @@ endfunction
 
 " Function: #stop {{{1
 function! sy#stop(bnum) abort
-  if !exists('b:sy')
+  let bvars = getbufvar(a:bnum, '')
+  if empty(bvars) || !has_key(bvars, 'sy')
     return
   endif
 

autoload/sy/sign.vim

@@ -42,16 +42,18 @@ endfunction
 
 " Function: #remove_all {{{1
 function! sy#sign#remove_all(bnum) abort
+  let sy = getbufvar(a:bnum, 'sy')
+
   if g:signify_sign_overwrite
-    execute 'sign unplace * buffer='. b:sy.buffer
+    execute 'sign unplace * buffer='. sy.buffer
   else
-    for hunk in b:sy.hunks
+    for hunk in sy.hunks
       for id in hunk.ids
         execute 'sign unplace' id
       endfor
     endfor
   endif
 
-  let b:sy.hunks = []
-  let b:sy.stats = [0, 0, 0]
+  let sy.hunks = []
+  let sy.stats = [0, 0, 0]
 endfunction

plugin/signify.vim

@@ -14,7 +14,6 @@ augroup signify
   autocmd VimEnter             * call sy#highlight#setup()
   autocmd BufRead,BufEnter     * let b:sy_path = resolve(expand('<afile>:p'))
   autocmd BufRead,BufWritePost * call sy#start(b:sy_path)
-
   autocmd BufDelete            * call sy#stop(expand('<abuf>'))
 
   if get(g:, 'signify_update_on_bufenter')