rewriter: detectEnd no longer passes undefined as token, fixing #750

lib/rewriter.js

@@ -29,10 +29,10 @@
     return true;
   };
   exports.Rewriter.prototype.detectEnd = function(i, condition, action) {
-    var levels, token;
+    var levels, token, tokens;
+    tokens = this.tokens;
     levels = 0;
-    while (true) {
-      token = this.tokens[i];
+    while (token = tokens[i]) {
       if (levels === 0 && condition.call(this, token, i)) {
         return action.call(this, token, i);
       }

src/rewriter.coffee

@@ -46,9 +46,9 @@ class exports.Rewriter
     true
 
   detectEnd: (i, condition, action) ->
+    {tokens} = this
     levels = 0
-    loop
-      token = @tokens[i]
+    while token = tokens[i]
       return action.call this, token, i     if levels is 0 and condition.call this, token, i
       return action.call this, token, i - 1 if not token or levels < 0
       if include EXPRESSION_START, token[0]

test/test_compilation.coffee

@@ -13,3 +13,10 @@ CoffeeScript.run("resultArray.push i for i of global", {noWrap: on, globals: on,
 ok 'setInterval' in global.resultArray
 
 ok 'passed' is CoffeeScript.eval '"passed"', noWrap: on, globals: on, fileName: 'tests'
+
+#750
+try
+  CoffeeScript.nodes 'f(->'
+  ok no
+catch e
+  eq e.message, 'unclosed CALL_START on line 1'