Bug 941099 - Default application handler is not correctly used when an alternate app handler exists. r=paolo

toolkit/components/jsdownloads/src/DownloadLegacy.js

@@ -200,7 +200,8 @@ DownloadLegacyTransfer.prototype = {
       contentType = aMIMEInfo.type;
 
       let appHandler = aMIMEInfo.preferredApplicationHandler;
-      if (appHandler instanceof Ci.nsILocalHandlerApp) {
+      if (aMIMEInfo.preferredAction == Ci.nsIMIMEInfo.useHelperApp &&
+          appHandler instanceof Ci.nsILocalHandlerApp) {
         launcherPath = appHandler.executable.path;
       }
     }

toolkit/components/jsdownloads/test/unit/common_test_Download.js

@@ -1521,6 +1521,7 @@ add_task(function test_launch() {
         source: httpUrl("source.txt"),
         target: getTempFile(TEST_TARGET_FILE_NAME).path,
         launcherPath: launcherPath,
+        launchWhenSucceeded: true
       });
 
       try {
@@ -1537,11 +1538,12 @@ add_task(function test_launch() {
       // it is created, thus we don't test calling "launch" before starting.
       download = yield promiseStartLegacyDownload(
                                          httpUrl("source.txt"),
-                                         { launcherPath: launcherPath });
+                                         { launcherPath: launcherPath,
+                                           launchWhenSucceeded: true });
       yield promiseDownloadStopped(download);
     }
 
-    do_check_false(download.launchWhenSucceeded);
+    do_check_true(download.launchWhenSucceeded);
 
     DownloadIntegration._deferTestOpenFile = Promise.defer();
     download.launch();

toolkit/components/jsdownloads/test/unit/head.js

@@ -341,6 +341,7 @@ function promiseStartLegacyDownload(aSourceUrl, aOptions) {
     localHandlerApp.executable = new FileUtils.File(aOptions.launcherPath);
 
     mimeInfo.preferredApplicationHandler = localHandlerApp;
+    mimeInfo.preferredAction = Ci.nsIMIMEInfo.useHelperApp;
   }
 
   if (aOptions && aOptions.launchWhenSucceeded) {