feat: Close tab and switch to recent tab when going back with no history, p=#11190

Co-authored-by: mr. m <91018726+mr-cheffy@users.noreply.github.com>

locales/en-US/browser/browser/preferences/zen-preferences.ftl

@@ -56,6 +56,9 @@ pane-settings-workspaces-title = Workspaces
 zen-tabs-unloader-enabled =
     .label = Enable Tab Unloader
 
+zen-tabs-close-on-back-with-no-history =
+    .label = Close tab and switch to its owner tab (or most recently used tab) when going back with no history
+
 zen-look-and-feel-compact-toolbar-themed =
     .label = Use themed background for compact toolbar
 

prefs/zen/zen.yaml

@@ -34,3 +34,6 @@
 
 - name: zen.tabs.open-pinned-in-new-tab
   value: true
+
+- name: zen.tabs.close-on-back-with-no-history
+  value: true

src/browser/base/content/browser-commands-js.patch

@@ -1,8 +1,19 @@
 diff --git a/browser/base/content/browser-commands.js b/browser/base/content/browser-commands.js
-index 939ca497b882b3f4200141ba1b6764fb5c846f45..36c830a503b004c0a332340f686c86cad68e9381 100644
+index 939ca497b882b3f4200141ba1b6764fb5c846f45..779cba5ff3df856a246321a36caa3725c054a314 100644
 --- a/browser/base/content/browser-commands.js
 +++ b/browser/base/content/browser-commands.js
-@@ -315,6 +315,10 @@ var BrowserCommands = {
+@@ -14,6 +14,10 @@ var BrowserCommands = {
+     const where = BrowserUtils.whereToOpenLink(aEvent, false, true);
+ 
+     if (where == "current") {
++      if (!gBrowser.webNavigation.canGoBack && gZenCommonActions.shouldCloseTabOnBack()) {
++        gBrowser.removeTab(gBrowser.selectedTab);
++        return;
++      }
+       try {
+         gBrowser.goBack();
+       } catch (ex) {}
+@@ -315,6 +319,10 @@ var BrowserCommands = {
        }
      }
  
@@ -13,7 +24,7 @@ index 939ca497b882b3f4200141ba1b6764fb5c846f45..36c830a503b004c0a332340f686c86ca
      // A notification intended to be useful for modular peformance tracking
      // starting as close as is reasonably possible to the time when the user
      // expressed the intent to open a new tab.  Since there are a lot of
-@@ -399,6 +403,11 @@ var BrowserCommands = {
+@@ -399,6 +407,11 @@ var BrowserCommands = {
        return;
      }
  
@@ -25,7 +36,7 @@ index 939ca497b882b3f4200141ba1b6764fb5c846f45..36c830a503b004c0a332340f686c86ca
      // Keyboard shortcuts that would close a tab that is pinned select the first
      // unpinned tab instead.
      if (
-@@ -406,8 +415,8 @@ var BrowserCommands = {
+@@ -406,8 +419,8 @@ var BrowserCommands = {
        (event.ctrlKey || event.metaKey || event.altKey) &&
        gBrowser.selectedTab.pinned
      ) {

src/browser/base/content/browser-gestureSupport-js.patch

@@ -0,0 +1,13 @@
+diff --git a/browser/base/content/browser-gestureSupport.js b/browser/base/content/browser-gestureSupport.js
+index a28d54bf72c0e6495b9586f220d1859aac794936..66154668b9f85ffbaacea1e8351370659260227b 100644
+--- a/browser/base/content/browser-gestureSupport.js
++++ b/browser/base/content/browser-gestureSupport.js
+@@ -832,7 +832,7 @@ var gHistorySwipeAnimation = {
+    * @return true if there is a previous page in history, false otherwise.
+    */
+   canGoBack: function HSA_canGoBack() {
+-    return gBrowser.webNavigation.canGoBack;
++    return gBrowser.webNavigation.canGoBack || gZenCommonActions.shouldCloseTabOnBack();
+   },
+ 
+   /**

src/browser/base/content/browser-js.patch

@@ -1,5 +1,5 @@
 diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
-index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627e4c0ba7c 100644
+index b4b79e7fb3228ba91bd8afa08659be0d88883725..b4801e2a3076139622d58f81943e61cd61ee1828 100644
 --- a/browser/base/content/browser.js
 +++ b/browser/base/content/browser.js
 @@ -31,6 +31,7 @@ ChromeUtils.defineESModuleGetters(this, {
@@ -10,7 +10,21 @@ index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627
    DevToolsSocketStatus:
      "resource://devtools/shared/security/DevToolsSocketStatus.sys.mjs",
    DownloadUtils: "resource://gre/modules/DownloadUtils.sys.mjs",
-@@ -2298,6 +2299,8 @@ var XULBrowserWindow = {
+@@ -822,7 +823,12 @@ function UpdateBackForwardCommands(aWebNavigation) {
+ 
+   var backDisabled = backCommand.hasAttribute("disabled");
+   var forwardDisabled = forwardCommand.hasAttribute("disabled");
+-  if (backDisabled == aWebNavigation.canGoBack) {
++  var canGoBack = aWebNavigation.canGoBack;
++  if (!canGoBack) {
++    canGoBack = gZenCommonActions.shouldCloseTabOnBack();
++  }
++  
++  if (backDisabled == canGoBack) {
+     if (backDisabled) {
+       backCommand.removeAttribute("disabled");
+     } else {
+@@ -2298,6 +2304,8 @@ var XULBrowserWindow = {
      AboutReaderParent.updateReaderButton(gBrowser.selectedBrowser);
      TranslationsParent.onLocationChange(gBrowser.selectedBrowser);
  
@@ -19,7 +33,7 @@ index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627
      PictureInPicture.updateUrlbarToggle(gBrowser.selectedBrowser);
  
      if (!gMultiProcessBrowser) {
-@@ -3809,7 +3812,7 @@ function warnAboutClosingWindow() {
+@@ -3809,7 +3817,7 @@ function warnAboutClosingWindow() {
  
    if (!isPBWindow && !toolbar.visible) {
      return gBrowser.warnAboutClosingTabs(
@@ -28,7 +42,7 @@ index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627
        gBrowser.closingTabsEnum.ALL
      );
    }
-@@ -3849,7 +3852,7 @@ function warnAboutClosingWindow() {
+@@ -3849,7 +3857,7 @@ function warnAboutClosingWindow() {
      return (
        isPBWindow ||
        gBrowser.warnAboutClosingTabs(
@@ -37,7 +51,7 @@ index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627
          gBrowser.closingTabsEnum.ALL
        )
      );
-@@ -3874,7 +3877,7 @@ function warnAboutClosingWindow() {
+@@ -3874,7 +3882,7 @@ function warnAboutClosingWindow() {
      AppConstants.platform != "macosx" ||
      isPBWindow ||
      gBrowser.warnAboutClosingTabs(
@@ -46,7 +60,7 @@ index b4b79e7fb3228ba91bd8afa08659be0d88883725..9e1d59b6a736107e55bda73686a4a627
        gBrowser.closingTabsEnum.ALL
      )
    );
-@@ -4796,6 +4799,9 @@ var ConfirmationHint = {
+@@ -4796,6 +4804,9 @@ var ConfirmationHint = {
      MozXULElement.insertFTLIfNeeded("toolkit/branding/brandings.ftl");
      MozXULElement.insertFTLIfNeeded("browser/confirmationHints.ftl");
      document.l10n.setAttributes(this._message, messageId, options.l10nArgs);

src/browser/components/preferences/zenTabsManagement.inc.xhtml

@@ -26,6 +26,9 @@
       <checkbox id="zenWorkspacesForceContainerTabsToWorkspace"
             data-l10n-id="zen-settings-workspaces-force-container-tabs-to-workspace"
             preference="zen.workspaces.force-container-workspace"/>
+      <checkbox id="zenTabsCloseOnBackWithNoHistory"
+            data-l10n-id="zen-tabs-close-on-back-with-no-history"
+            preference="zen.tabs.close-on-back-with-no-history"/>
 </groupbox>
 
 <hbox id="zenTabsUnloadCategory"

src/zen/common/ZenCommonUtils.mjs

@@ -107,4 +107,19 @@ var gZenCommonActions = {
       timer = setTimeout(() => f.apply(this, args), delay);
     };
   },
+
+  /**
+   * Determines if a tab should be closed when navigating back with no history.
+   * Only tabs with an owner that are not pinned and not empty are eligible.
+   * Respects the user preference zen.tabs.close-on-back-with-no-history.
+   *
+   * @return {boolean} True if the tab should be closed on back
+   */
+  shouldCloseTabOnBack() {
+    if (!Services.prefs.getBoolPref('zen.tabs.close-on-back-with-no-history', true)) {
+      return false;
+    }
+    const tab = gBrowser.selectedTab;
+    return Boolean(tab.owner && !tab.pinned && !tab.hasAttribute('zen-empty-tab'));
+  },
 };