diff --git a/lib/ace/background_tokenizer.js b/lib/ace/background_tokenizer.js
index 0ee8990c..e5fe73bd 100644
--- a/lib/ace/background_tokenizer.js
+++ b/lib/ace/background_tokenizer.js
@@ -130,8 +130,8 @@ var BackgroundTokenizer = function(tokenizer, editor) {
     };
 
     this.$tokenizeRows = function(firstRow, lastRow) {
-        if (!this.doc)
-            return [];
+        if (!this.doc || isNaN(firstRow) || isNaN(lastRow))
+            return [{'state':'start','tokens':[]}];
             
         var rows = [];
 
diff --git a/lib/ace/edit_session/bracket_match.js b/lib/ace/edit_session/bracket_match.js
index 477125a1..3fcf1413 100644
--- a/lib/ace/edit_session/bracket_match.js
+++ b/lib/ace/edit_session/bracket_match.js
@@ -92,15 +92,15 @@ function BracketMatch() {
         while (true) {
         
             while (valueIndex >= 0) {
-                var char = value.charAt(valueIndex);
-                if (char == openBracket) {
+                var chr = value.charAt(valueIndex);
+                if (chr == openBracket) {
                     depth -= 1;
                     if (depth == 0) {
                         return {row: iterator.getCurrentTokenRow(),
                             column: valueIndex + iterator.getCurrentTokenColumn()};
                     }
                 }
-                else if (char == bracket) {
+                else if (chr == bracket) {
                     depth += 1;
                 }
                 valueIndex -= 1;
@@ -146,15 +146,15 @@ function BracketMatch() {
             var value = token.value;
             var valueLength = value.length;
             while (valueIndex < valueLength) {
-                var char = value.charAt(valueIndex);
-                if (char == closingBracket) {
+                var chr = value.charAt(valueIndex);
+                if (chr == closingBracket) {
                     depth -= 1;
                     if (depth == 0) {
                         return {row: iterator.getCurrentTokenRow(),
                             column: valueIndex + iterator.getCurrentTokenColumn()};
                     }
                 }
-                else if (char == bracket) {
+                else if (chr == bracket) {
                     depth += 1;
                 }
                 valueIndex += 1;