[brace-fold addon] Fix confusion when there are both braces and brackets on a line

Closes #6847

Author: marijnh

addon/fold/brace-fold.js

@@ -13,9 +13,9 @@
 
 CodeMirror.registerHelper("fold", "brace", function(cm, start) {
   var line = start.line, lineText = cm.getLine(line);
-  var tokenType;
 
   function findOpening(openCh) {
+    var tokenType;
     for (var at = start.ch, pass = 0;;) {
       var found = at <= 0 ? -1 : lineText.lastIndexOf(openCh, at - 1);
       if (found == -1) {
@@ -26,40 +26,42 @@ CodeMirror.registerHelper("fold", "brace", function(cm, start) {
       }
       if (pass == 1 && found < start.ch) break;
       tokenType = cm.getTokenTypeAt(CodeMirror.Pos(line, found + 1));
-      if (!/^(comment|string)/.test(tokenType)) return found + 1;
+      if (!/^(comment|string)/.test(tokenType)) return {ch: found + 1, tokenType: tokenType};
       at = found - 1;
     }
   }
 
-  var startBrace = findOpening("{"), startBracket = findOpening("[")
-  var startToken, endToken, startCh
-  if (startBrace != null && (startBracket == null || startBracket > startBrace)) {
-    startCh = startBrace; startToken = "{"; endToken = "}"
-  } else if (startBracket != null) {
-    startCh = startBracket; startToken = "["; endToken = "]"
-  } else {
-    return
-  }
-
-  var count = 1, lastLine = cm.lastLine(), end, endCh;
-  outer: for (var i = line; i <= lastLine; ++i) {
-    var text = cm.getLine(i), pos = i == line ? startCh : 0;
-    for (;;) {
-      var nextOpen = text.indexOf(startToken, pos), nextClose = text.indexOf(endToken, pos);
-      if (nextOpen < 0) nextOpen = text.length;
-      if (nextClose < 0) nextClose = text.length;
-      pos = Math.min(nextOpen, nextClose);
-      if (pos == text.length) break;
-      if (cm.getTokenTypeAt(CodeMirror.Pos(i, pos + 1)) == tokenType) {
-        if (pos == nextOpen) ++count;
-        else if (!--count) { end = i; endCh = pos; break outer; }
+  function findRange(startToken, endToken, found) {
+    var count = 1, lastLine = cm.lastLine(), end, startCh = found.ch, endCh
+    outer: for (var i = line; i <= lastLine; ++i) {
+      var text = cm.getLine(i), pos = i == line ? startCh : 0;
+      for (;;) {
+        var nextOpen = text.indexOf(startToken, pos), nextClose = text.indexOf(endToken, pos);
+        if (nextOpen < 0) nextOpen = text.length;
+        if (nextClose < 0) nextClose = text.length;
+        pos = Math.min(nextOpen, nextClose);
+        if (pos == text.length) break;
+        if (cm.getTokenTypeAt(CodeMirror.Pos(i, pos + 1)) == found.tokenType) {
+          if (pos == nextOpen) ++count;
+          else if (!--count) { end = i; endCh = pos; break outer; }
+        }
+        ++pos;
       }
-      ++pos;
     }
+
+    if (end == null || line == end) return null
+    return {from: CodeMirror.Pos(line, startCh),
+            to: CodeMirror.Pos(end, endCh)};
+  }
+
+  var startBrace = findOpening("{"), startBracket = findOpening("[")
+  if (startBrace && (!startBracket || startBracket.ch > startBrace.ch)) {
+    return findRange("{", "}", startBrace) || (startBracket && findRange("[", "]", startBracket))
+  } else if (startBracket) {
+    return findRange("[", "]", startBracket) || (startBrace && findRange("{", "}", startBrace))
+  } else {
+    return null
   }
-  if (end == null || line == end) return;
-  return {from: CodeMirror.Pos(line, startCh),
-          to: CodeMirror.Pos(end, endCh)};
 });
 
 CodeMirror.registerHelper("fold", "import", function(cm, start) {