fix($http): properly access request headers with mixed case

Fixes angular#10881
Closes angular#10883

Author: pkozlowski-opensource

src/ng/http.js

@@ -37,19 +37,24 @@ function isJsonLike(str) {
  * @returns {Object} Parsed headers as key value object
  */
 function parseHeaders(headers) {
-  var parsed = createMap(), key, val, i;
-
-  if (!headers) return parsed;
-
-  forEach(headers.split('\n'), function(line) {
-    i = line.indexOf(':');
-    key = lowercase(trim(line.substr(0, i)));
-    val = trim(line.substr(i + 1));
+  var parsed = createMap(), i;
 
+  function fillInParsed(key, val) {
     if (key) {
       parsed[key] = parsed[key] ? parsed[key] + ', ' + val : val;
     }
-  });
+  }
+
+  if (isString(headers)) {
+    forEach(headers.split('\n'), function(line) {
+      i = line.indexOf(':');
+      fillInParsed(lowercase(trim(line.substr(0, i))), trim(line.substr(i + 1)));
+    });
+  } else if (isObject(headers)) {
+    forEach(headers, function(headerVal, headerKey) {
+      fillInParsed(lowercase(headerKey), trim(headerVal));
+    });
+  }
 
   return parsed;
 }
@@ -68,7 +73,7 @@ function parseHeaders(headers) {
  *   - if called with no arguments returns an object containing all headers.
  */
 function headersGetter(headers) {
-  var headersObj = isObject(headers) ? headers : undefined;
+  var headersObj;
 
   return function(name) {
     if (!headersObj) headersObj =  parseHeaders(headers);

test/ng/httpSpec.js

@@ -1038,6 +1038,18 @@ describe('$http', function() {
           expect(callback).toHaveBeenCalledOnce();
         });
 
+        it('should have access to request headers with mixed case', function() {
+          $httpBackend.expect('POST', '/url', 'header1').respond(200);
+          $http.post('/url', 'req', {
+            headers: {H1: 'header1'},
+            transformRequest: function(data, headers) {
+              return headers('H1');
+            }
+          }).success(callback);
+          $httpBackend.flush();
+
+          expect(callback).toHaveBeenCalledOnce();
+        });
 
         it('should pipeline more functions', function() {
           function first(d, h) {return d + '-first' + ':' + h('h1');}