gh-14183: Dont open space routing tabs in background (gh-14360)

src/zen/common/sys/ui/ZenSpaceRoutingNavigation.sys.mjs

@@ -35,13 +35,6 @@ export class ZenSpaceRoutingNavigation extends ZenUIComponent {
       return;
     }
 
-    // The tab we spawn for a route must be allowed to load once without being
-    // redirected again, regardless of when its workspace attribute lands.
-    if (aBrowser._zenSkipNavRouteOnce) {
-      aBrowser._zenSkipNavRouteOnce = false;
-      return;
-    }
-
     let uri;
     try {
       uri = aRequest.QueryInterface(Ci.nsIChannel).URI;
@@ -80,16 +73,49 @@ export class ZenSpaceRoutingNavigation extends ZenUIComponent {
     }
 
     const currentWorkspaceId = tab.getAttribute("zen-workspace-id");
-    if (
-      !win.gZenSpaceRoutingManager.shouldRedirectNavigation(
+    const targetWorkspaceId =
+      win.gZenSpaceRoutingManager.getRedirectTargetWorkspaceId(
         uri.spec,
         currentWorkspaceId,
         win
-      )
-    ) {
+      );
+    if (!targetWorkspaceId) {
       return;
     }
 
+    // A brand-new tab whose very first real navigation this is (a
+    // target="_blank" link, window.open(), or a freshly opened tab) is still
+    // showing its initial about:blank document. There is nothing to preserve,
+    // so rather than cancelling the load and spawning a duplicate tab - which
+    // would leave this one behind empty - just move this very tab into the
+    // destination space and let the in-flight load finish in place.
+    const isInitialDocument =
+      aBrowser.browsingContext?.currentWindowGlobal?.isInitialDocument ?? false;
+    if (isInitialDocument) {
+      const wasSelected = tab.selected;
+      // Defer so we don't mutate the tab strip from inside a progress notification.
+      win.setTimeout(() => {
+        if (!tab.isConnected) {
+          return;
+        }
+        gBrowser.selectedTab = tab.owner;
+        win.gZenWorkspaces.moveTabToWorkspace(tab, targetWorkspaceId);
+        if (wasSelected) {
+          const targetWorkspace =
+            win.gZenWorkspaces.getWorkspaceFromId(targetWorkspaceId);
+          if (targetWorkspace) {
+            win.gZenWorkspaces.lastSelectedWorkspaceTabs[targetWorkspaceId] =
+              tab;
+            win.gZenWorkspaces.changeWorkspace(targetWorkspace);
+          }
+        }
+      }, 0);
+      return;
+    }
+
+    // An already-loaded page is navigating in place. Preserve it in its current
+    // tab and re-open the destination in a new routed tab instead.
+    //
     // Under Fission the parent-side aRequest is a RemoteWebProgress stand-in
     // whose cancel()/loadInfo throw NS_ERROR_NOT_IMPLEMENTED (the real channel
     // lives in the content process). Stop the in-place load through the browser,
@@ -111,13 +137,14 @@ export class ZenSpaceRoutingNavigation extends ZenUIComponent {
 
     // Defer so we don't mutate the tab strip from inside a progress notification.
     win.setTimeout(() => {
-      const newTab = gBrowser.addTab(urlToOpen, {
+      gBrowser.addTab(urlToOpen, {
         triggeringPrincipal: principal,
         ownerTab: tab.isConnected ? tab : null,
+        // The user was actively navigating this tab, so follow the navigation
+        // into the routed tab instead of opening it in the background (addTab
+        // defaults inBackground to true).
+        inBackground: false,
       });
-      if (newTab?.linkedBrowser) {
-        newTab.linkedBrowser._zenSkipNavRouteOnce = true;
-      }
     }, 0);
   }
 }

src/zen/space-routing/ZenSpaceRoutingManager.sys.mjs

@@ -104,7 +104,7 @@ class nsZenSpaceRoutingManager {
         break;
       default: {
         const targetWorkspace =
-          win?.gZenWorkspaces?.getWorkspaceFromId(targetRoute);
+          win.gZenWorkspaces.getWorkspaceFromId(targetRoute);
 
         if (targetWorkspace) {
           userContextId = targetWorkspace.containerTabId;
@@ -159,8 +159,26 @@ class nsZenSpaceRoutingManager {
    * @returns {boolean} True when the navigation should open in a new routed tab
    */
   shouldRedirectNavigation(uriString, currentWorkspaceId, win) {
+    return !!this.getRedirectTargetWorkspaceId(
+      uriString,
+      currentWorkspaceId,
+      win
+    );
+  }
+
+  /**
+   * Resolves the destination space for an in-place top-level navigation, or
+   * null when the navigation should be left alone (no rule, the destination is
+   * "most-recent-space", the tab already lives there, or the space is gone).
+   *
+   * @param {string} uriString - The destination URI
+   * @param {string|null} currentWorkspaceId - The zen-workspace-id of the navigating tab
+   * @param {Window} win - The owning browser window
+   * @returns {string|null} The target workspace id, or null to leave the navigation in place
+   */
+  getRedirectTargetWorkspaceId(uriString, currentWorkspaceId, win) {
     if (!win?.gZenWorkspaces?.workspaceEnabled) {
-      return false;
+      return null;
     }
 
     const targetRoute = this.routeUri(uriString, { fromExternal: false });
@@ -170,11 +188,13 @@ class nsZenSpaceRoutingManager {
       targetRoute === "most-recent-space" ||
       targetRoute === currentWorkspaceId
     ) {
-      return false;
+      return null;
     }
 
     // Only redirect when the destination space actually exists.
-    return !!win.gZenWorkspaces.getWorkspaceFromId(targetRoute);
+    return win.gZenWorkspaces.getWorkspaceFromId(targetRoute)
+      ? targetRoute
+      : null;
   }
 
   /**

src/zen/spaces/ZenSpaceManager.mjs

@@ -2298,12 +2298,12 @@ class nsZenWorkspaces {
   }
 
   onBeforeTabSelect(aTab) {
-    if (this.#inChangingWorkspace) {
+    if (this.#inChangingWorkspace || !aTab) {
       // Just in case, Let's not do these checks while we are
       // in the middle of changing workspace,
       return false;
     }
-    const tabSpace = aTab?.getAttribute("zen-workspace-id");
+    const tabSpace = aTab.getAttribute("zen-workspace-id");
     if (
       tabSpace &&
       tabSpace !== this.activeWorkspace &&