fixed yield return producing incorrect output when used outside of the last line

lib/coffee-script/nodes.js

@@ -652,13 +652,18 @@
     };
 
     Return.prototype.compileNode = function(o) {
-      var answer;
+      var answer, exprIsYieldReturn, ref3;
       answer = [];
-      answer.push(this.makeCode(this.tab + ("return" + (this.expression ? " " : ""))));
+      exprIsYieldReturn = (ref3 = this.expression) != null ? typeof ref3.isYieldReturn === "function" ? ref3.isYieldReturn() : void 0 : void 0;
+      if (!exprIsYieldReturn) {
+        answer.push(this.makeCode(this.tab + ("return" + (this.expression ? " " : ""))));
+      }
       if (this.expression) {
         answer = answer.concat(this.expression.compileToFragments(o, LEVEL_PAREN));
       }
-      answer.push(this.makeCode(";"));
+      if (!exprIsYieldReturn) {
+        answer.push(this.makeCode(";"));
+      }
       return answer;
     };
 
@@ -2361,6 +2366,10 @@
       return (ref3 = this.operator) === 'yield' || ref3 === 'yield*';
     };
 
+    Op.prototype.isYieldReturn = function() {
+      return this.isYield() && this.first instanceof Return;
+    };
+
     Op.prototype.isUnary = function() {
       return !this.second;
     };
@@ -2531,7 +2540,9 @@
         this.error('yield statements must occur within a function generator.');
       }
       if (indexOf.call(Object.keys(this.first), 'expression') >= 0 && !(this.first instanceof Throw)) {
-        if (this.first.expression != null) {
+        if (this.isYieldReturn()) {
+          parts.push(this.first.compileToFragments(o, LEVEL_TOP));
+        } else if (this.first.expression != null) {
           parts.push(this.first.expression.compileToFragments(o, LEVEL_OP));
         }
       } else {

src/nodes.coffee

@@ -453,11 +453,13 @@ exports.Return = class Return extends Base
 
   compileNode: (o) ->
     answer = []
+    exprIsYieldReturn = @expression?.isYieldReturn?()
     # TODO: If we call expression.compile() here twice, we'll sometimes get back different results!
-    answer.push @makeCode @tab + "return#{if @expression then " " else ""}"
+    unless exprIsYieldReturn
+      answer.push @makeCode @tab + "return#{if @expression then " " else ""}"
     if @expression
       answer = answer.concat @expression.compileToFragments o, LEVEL_PAREN
-    answer.push @makeCode ";"
+    answer.push @makeCode ";" unless exprIsYieldReturn
     return answer
 
 #### Value
@@ -1674,6 +1676,9 @@ exports.Op = class Op extends Base
   isYield: ->
     @operator in ['yield', 'yield*']
 
+  isYieldReturn: ->
+    @isYield() and @first instanceof Return
+
   isUnary: ->
     not @second
 
@@ -1802,7 +1807,10 @@ exports.Op = class Op extends Base
     if not o.scope.parent?
       @error 'yield statements must occur within a function generator.'
     if 'expression' in Object.keys(@first) and not (@first instanceof Throw)
-      parts.push @first.expression.compileToFragments o, LEVEL_OP if @first.expression?
+      if @isYieldReturn()
+        parts.push @first.compileToFragments o, LEVEL_TOP
+      else if @first.expression?
+        parts.push @first.expression.compileToFragments o, LEVEL_OP
     else
       parts.push [@makeCode "(#{op} "]
       parts.push @first.compileToFragments o, LEVEL_OP

test/generators.coffee

@@ -38,6 +38,15 @@ test "last line yields are returned", ->
   y = x.next 42
   ok y.value is 42 and y.done is true
 
+test "yield return can be used anywhere in the function body", ->
+  x = do ->
+    if true
+      yield return true
+    return false
+
+  y = x.next()
+  ok y.value is true and y.done is true
+
 test "bound generator", ->
   obj =
     bound: ->