Fix range header regression

Range headers should not be sent when requesting the entire resource.
This fixes compatibility with Microsoft IIS web server.

Introduced in work on issue shaka-project#1788

Change-Id: I151a2f15d4f5e95531e16d5372ee9a051135f12f

lib/util/networking.js

@@ -41,9 +41,11 @@ shaka.util.Networking = class {
     const request = shaka.net.NetworkingEngine.makeRequest(
         uris, retryParameters);
 
-    // Set the Range header. Note that some web servers don't accept Range
-    // headers, so don't set one if it's not strictly required.
-    if (start != null) {
+    if (start == 0 && end == null) {
+      // This is a request for the entire segment.  The Range header is not
+      // required.  Note that some web servers don't accept Range headers, so
+      // don't set one if it's not strictly required.
+    } else {
       if (end) {
         request.headers['Range'] = 'bytes=' + start + '-' + end;
       } else {

test/net/networking_engine_unit.js

@@ -1209,7 +1209,22 @@ describe('NetworkingEngine', /** @suppress {accessControls} */ function() {
    */
   function createRequest(uri, retryParameters) {
     retryParameters = retryParameters ||
-                          shaka.net.NetworkingEngine.defaultRetryParameters();
+        shaka.net.NetworkingEngine.defaultRetryParameters();
     return shaka.net.NetworkingEngine.makeRequest([uri], retryParameters);
   }
+
+  describe('createSegmentRequest', () => {
+    it('does not add range headers to requests for the whole segment', () => {
+      // You had _one_ job, createSegmentRequest!
+
+      const request = shaka.util.Networking.createSegmentRequest(
+          /* uris= */ ['/foo.mp4'],
+          /* start= */ 0,
+          /* end= */ null,
+          shaka.net.NetworkingEngine.defaultRetryParameters());
+
+      const keys = Object.keys(request.headers).map((k) => k.toLowerCase());
+      expect(keys).not.toContain('range');
+    });
+  });
 });  // describe('NetworkingEngine')

test/test/util/fake_networking_engine.js

@@ -314,14 +314,20 @@ shaka.test.FakeNetworkingEngine = class {
    * @param {?number} endByte
    */
   static expectRangeRequest(requestSpy, uri, startByte, endByte) {
-    let range = 'bytes=' + startByte + '-';
-    if (endByte != null) range += endByte;
+    const headers = {};
+    if (startByte == 0 && endByte == null) {
+      // No header required.
+    } else {
+      let range = 'bytes=' + startByte + '-';
+      if (endByte != null) range += endByte;
+      headers['Range'] = range;
+    }
 
     expect(requestSpy).toHaveBeenCalledWith(
         shaka.net.NetworkingEngine.RequestType.SEGMENT,
         jasmine.objectContaining({
           uris: [uri],
-          headers: jasmine.objectContaining({'Range': range}),
+          headers: headers,
         }));
   }
 };