Fix issue #1964

lib/sinon/behavior.js

@@ -170,7 +170,8 @@ var proto = {
         } else if (this.reject) {
             return (this.promiseLibrary || Promise).reject(this.returnValue);
         } else if (this.callsThrough) {
-            return this.stub.wrappedMethod.apply(context, args);
+            var wrappedMethod = this.effectiveWrappedMethod();
+            return wrappedMethod.apply(context, args);
         } else if (typeof this.returnValue !== "undefined") {
             return this.returnValue;
         } else if (typeof this.callArgAt === "number") {
@@ -180,6 +181,15 @@ var proto = {
         return this.returnValue;
     },
 
+    effectiveWrappedMethod: function effectiveWrappedMethod() {
+        for (var stubb = this.stub; stubb; stubb = stubb.parent) {
+            if (stubb.wrappedMethod) {
+                return stubb.wrappedMethod;
+            }
+        }
+        throw new Error("Unable to find wrapped method");
+    },
+
     onCall: function onCall(index) {
         return this.stub.onCall(index);
     },

test/issues/issues-test.js

@@ -600,6 +600,26 @@ describe("issues", function() {
         });
     });
 
+    describe("#1964", function() {
+        it("should allow callThrough on a withArgs fake", function() {
+            var calledThrough = false;
+            var obj = {
+                method: function() {
+                    calledThrough = true;
+                }
+            };
+
+            var baseStub = sinon.stub(obj, "method");
+            baseStub.throws("Should always hit the withArgs fake");
+            var argsStub = baseStub.withArgs("foo").callThrough();
+
+            obj.method("foo");
+
+            sinon.assert.calledOnce(argsStub);
+            assert.isTrue(calledThrough);
+        });
+    });
+
     describe("#2016", function() {
         function Foo() {
             return;