Bug 1170011 - Disable infinite recursion on the View Source command; r=jaws

This disables the View Source command on view-source documents in the
view-source-in-tab mode.

browser/base/content/browser-context.inc

@@ -382,7 +382,7 @@
                 label="&viewPageSourceCmd.label;"
                 accesskey="&viewPageSourceCmd.accesskey;"
                 oncommand="BrowserViewSource(gContextMenu.browser);"
-                observes="isImage"/>
+                observes="canViewSource"/>
       <menuitem id="context-viewinfo"
                 label="&viewPageInfoCmd.label;"
                 accesskey="&viewPageInfoCmd.accesskey;"

browser/base/content/browser-sets.inc

@@ -39,7 +39,7 @@
 
     <commandset id="editMenuCommands"/>
 
-    <command id="View:PageSource" oncommand="BrowserViewSource(window.gBrowser.selectedBrowser);" observes="isImage"/>
+    <command id="View:PageSource" oncommand="BrowserViewSource(window.gBrowser.selectedBrowser);" observes="canViewSource"/>
     <command id="View:PageInfo" oncommand="BrowserPageInfo();"/>
     <command id="View:FullScreen" oncommand="BrowserFullScreen();"/>
     <command id="View:ReaderView" oncommand="ReaderParent.toggleReaderMode(event);"/>
@@ -174,6 +174,7 @@
                  oncommand="gPopupBlockerObserver.dontShowMessage();"/>
     <broadcaster id="blockedPopupsSeparator"/>
     <broadcaster id="isImage"/>
+    <broadcaster id="canViewSource"/>
     <broadcaster id="isFrameImage"/>
     <broadcaster id="singleFeedMenuitemState" disabled="true"/>
     <broadcaster id="multipleFeedsMenuState" hidden="true"/>
@@ -231,7 +232,9 @@
     <broadcaster id="devtoolsMenuBroadcaster_PageSource"
                  label="&pageSourceCmd.label;"
                  key="key_viewSource"
-                 command="View:PageSource"/>
+                 command="View:PageSource">
+      <observes element="canViewSource" attribute="disabled"/>
+    </broadcaster>
     <broadcaster id="devtoolsMenuBroadcaster_ErrorConsole"
                  label="&errorConsoleCmd.label;"
                  command="Tools:ErrorConsole"/>

browser/base/content/browser.js

@@ -4049,6 +4049,10 @@ var XULBrowserWindow = {
     delete this.isImage;
     return this.isImage = document.getElementById("isImage");
   },
+  get canViewSource () {
+    delete this.canViewSource;
+    return this.canViewSource = document.getElementById("canViewSource");
+  },
 
   init: function () {
     // Initialize the security button's state and tooltip text.
@@ -4206,6 +4210,7 @@ var XULBrowserWindow = {
       if (aRequest) {
         let msg = "";
         let location;
+        let canViewSource = true;
         // Get the URI either from a channel or a pseudo-object
         if (aRequest instanceof nsIChannel || "URI" in aRequest) {
           location = aRequest.URI;
@@ -4214,6 +4219,9 @@ var XULBrowserWindow = {
           if (location.scheme == "keyword" && aWebProgress.isTopLevel)
             gBrowser.userTypedValue = null;
 
+          canViewSource = !Services.prefs.getBoolPref("view_source.tab") ||
+                          location.scheme != "view-source";
+
           if (location.spec != "about:blank") {
             switch (aStatus) {
               case Components.results.NS_ERROR_NET_TIMEOUT:
@@ -4227,10 +4235,18 @@ var XULBrowserWindow = {
         this.setDefaultStatus(msg);
 
         // Disable menu entries for images, enable otherwise
-        if (browser.documentContentType && BrowserUtils.mimeTypeIsTextBased(browser.documentContentType))
+        if (browser.documentContentType && BrowserUtils.mimeTypeIsTextBased(browser.documentContentType)) {
           this.isImage.removeAttribute('disabled');
-        else
+        } else {
+          canViewSource = false;
           this.isImage.setAttribute('disabled', 'true');
+        }
+
+        if (canViewSource) {
+          this.canViewSource.removeAttribute('disabled');
+        } else {
+          this.canViewSource.setAttribute('disabled', 'true');
+        }
       }
 
       this.isBusy = false;

browser/base/content/test/general/browser.ini

@@ -475,6 +475,7 @@ skip-if = os == "linux" || e10s # Bug 1073339 - Investigate autocomplete test un
 [browser_urlbar_search_healthreport.js]
 [browser_urlbar_searchsettings.js]
 [browser_utilityOverlay.js]
+[browser_viewSourceInTabOnViewSource.js]
 [browser_visibleFindSelection.js]
 [browser_visibleLabel.js]
 [browser_visibleTabs.js]

browser/base/content/test/general/browser_viewSourceInTabOnViewSource.js

@@ -0,0 +1,47 @@
+function* wait_while_tab_is_busy(tab) {
+  yield BrowserTestUtils.waitForEvent(tab, "TabAttrModified", false,
+    event => event.detail.changed.indexOf("busy") >= 0 &&
+             !tab.hasAttribute("busy")
+  );
+}
+
+// This function waits for the tab to stop being busy instead of waiting for it
+// to load, since the canViewSource change happens at that time.
+let with_new_tab_opened = Task.async(function* (options, taskFn) {
+  let tab = yield BrowserTestUtils.openNewForegroundTab(options.gBrowser, options.url, false);
+  yield wait_while_tab_is_busy(tab);
+  yield taskFn(tab.linkedBrowser);
+  gBrowser.removeTab(tab);
+});
+
+add_task(function*() {
+  yield new Promise((resolve) => {
+    SpecialPowers.pushPrefEnv({"set": [
+                                ["view_source.tab", true],
+                              ]}, resolve);
+  });
+});
+
+add_task(function* test_regular_page() {
+  function* test_expect_view_source_enabled(browser) {
+    ok(!XULBrowserWindow.canViewSource.hasAttribute("disabled"),
+       "View Source should be enabled");
+  }
+
+  yield with_new_tab_opened({
+    gBrowser,
+    url: "http://example.com",
+  }, test_expect_view_source_enabled);
+});
+
+add_task(function* test_view_source_page() {
+  function* test_expect_view_source_disabled(browser) {
+    ok(XULBrowserWindow.canViewSource.hasAttribute("disabled"),
+       "View Source should be disabled");
+  }
+
+  yield with_new_tab_opened({
+    gBrowser,
+    url: "view-source:http://example.com",
+  }, test_expect_view_source_disabled);
+});