fix($http) No error for json-like repsonses without "application/json" content-type

src/ng/http.js

@@ -137,10 +137,15 @@ function defaultHttpResponseTransform(data, headers) {
 
     if (tempData) {
       var contentType = headers('Content-Type');
-      if ((contentType && (contentType.indexOf(APPLICATION_JSON) === 0)) || isJsonLike(tempData)) {
+      var hasJsonContentType = contentType && (contentType.indexOf(APPLICATION_JSON) === 0);
+
+      if (hasJsonContentType || isJsonLike(tempData)) {
         try {
           data = fromJson(tempData);
         } catch (e) {
+          if (!hasJsonContentType) {
+            return data;
+          }
           throw $httpMinErr('baddata', 'Data must be a valid JSON object. Received: "{0}". ' +
           'Parse error: "{1}"', data, e);
         }

test/ng/httpSpec.js

@@ -1380,8 +1380,45 @@ describe('$http', function() {
             expect(errCallback.calls.mostRecent().args[0]).toEqualMinErr('$http', 'baddata');
           });
 
-        });
+          it('should not throw an error if JSON is invalid but content-type is not application/json', function() {
+            $httpBackend.expect('GET', '/url').respond('{abcd}', {'Content-Type': 'text/plain'});
+
+            $http.get('/url').then(callback);
+            $httpBackend.flush();
+
+            expect(callback).toHaveBeenCalledOnce();
+          });
+
+          it('should not throw an error if JSON is invalid but content-type is not specified', function() {
+            $httpBackend.expect('GET', '/url').respond('{abcd}');
+
+            $http.get('/url').then(callback);
+            $httpBackend.flush();
+
+            expect(callback).toHaveBeenCalledOnce();
+          });
 
+          it('should return response unprocessed if JSON is invalid but content-type is not application/json', function() {
+            var response = '{abcd}';
+            $httpBackend.expect('GET', '/url').respond(response, {'Content-Type': 'text/plain'});
+
+            $http.get('/url').then(callback);
+            $httpBackend.flush();
+
+            expect(callback.calls.mostRecent().args[0].data).toBe(response);
+          });
+
+          it('should return response unprocessed if JSON is invalid but content-type is not specified', function() {
+            var response = '{abcd}';
+            $httpBackend.expect('GET', '/url').respond(response);
+
+            $http.get('/url').then(callback);
+            $httpBackend.flush();
+
+            expect(callback.calls.mostRecent().args[0].data).toBe(response);
+          });
+
+        });
 
         it('should have access to response headers', function() {
           $httpBackend.expect('GET', '/url').respond(200, 'response', {h1: 'header1'});