[closetag addon] Fix behavior when typing > after /

Closes codemirror#6038

Author: marijnh

addon/edit/closetag.js

@@ -74,7 +74,7 @@
       if (!tagName ||
           tok.type == "string" && (tok.end != pos.ch || !/[\"\']/.test(tok.string.charAt(tok.string.length - 1)) || tok.string.length == 1) ||
           tok.type == "tag" && tagInfo.close ||
-          tok.string.indexOf("/") == (tok.string.length - 1) || // match something like <someTagName />
+          tok.string.indexOf("/") == (pos.ch - tok.start - 1) || // match something like <someTagName />
           dontCloseTags && indexOf(dontCloseTags, lowerTagName) > -1 ||
           closingTagExists(cm, inner.mode.xmlCurrentContext && inner.mode.xmlCurrentContext(state) || [], tagName, pos, true))
         return CodeMirror.Pass;