Fix indent after an empty tag with '>' in attributes

A line like <input @input="(e) => update(e)" /> was taken as an empty
tag without '/>', as '>' in '=>' matched its end, so the next line was
indented one level less. Skip '>' in quotes, and don't take '/>' as the
end of an empty tag.

indent/vue.vim

@@ -19,7 +19,10 @@ function! s:Init()
   " To adjust HTML
   let s:empty_tagname = '(area|base|br|col|embed|hr|input|img|'
         \.'keygen|link|meta|param|source|track|wbr)'
-  let s:empty_tag = '\v\<'.s:empty_tagname.'.*(/)@<!\>'
+  " Empty tag ending with '>' but not '/>'. '>' in quotes like
+  " @input="(e) => update(e)" doesn't end the tag
+  let s:empty_tag = '\v\<'.s:empty_tagname
+        \ .'>("[^"]*"|''[^'']*''|[^\>"''/]|/(\>)@!)*\>'
   let s:empty_tag_start = '\v\<'.s:empty_tagname.'[^>]*$'
   let s:empty_tag_end = '\v^\s*[^<>/]*\/?\>\s*'
   let s:tag_start = '\v^\s*\<\w*'   " <