fix: Fixed selecting split views with 2 windows turning them to blank tabs, b=no-bug, c=split-view, tabs

prefs/zen/zen.yaml

@@ -14,9 +14,6 @@
 - name: zen.tabs.essentials.max
   value: 12
 
-- name: zen.tabs.essentials.dnd-promo-enabled
-  value: true
-
 - name: zen.tabs.show-newtab-vertical
   value: true
 

src/browser/components/sessionstore/SessionStore-sys-mjs.patch

@@ -1,5 +1,5 @@
 diff --git a/browser/components/sessionstore/SessionStore.sys.mjs b/browser/components/sessionstore/SessionStore.sys.mjs
-index 2a055f0c5f34f0a2667f659185120c07d38f4e41..27f85dc47d66f2f83820e964198832d82bff04c1 100644
+index 2a055f0c5f34f0a2667f659185120c07d38f4e41..c0ab92bfc89306e4e7d3a43097beb2dc5c9189be 100644
 --- a/browser/components/sessionstore/SessionStore.sys.mjs
 +++ b/browser/components/sessionstore/SessionStore.sys.mjs
 @@ -127,6 +127,9 @@ const TAB_EVENTS = [
@@ -219,8 +219,8 @@ index 2a055f0c5f34f0a2667f659185120c07d38f4e41..27f85dc47d66f2f83820e964198832d8
 +      aWindow.document.documentElement.setAttribute("zen-unsynced-window", "true");
 +    }
 +    aWindow.gZenFolders?.restoreDataFromSessionStore(winData.folders);
-+    aWindow.gZenViewSplitter?.restoreDataFromSessionStore(winData.splitViewData);
 +    aWindow.gZenWorkspaces?.restoreWorkspacesFromSessionStore(winData);
++    aWindow.gZenViewSplitter?.restoreDataFromSessionStore(winData.splitViewData);
  
      // Move the originally open tabs to the end.
      if (initialTabs) {

src/zen/drag-and-drop/ZenDragAndDrop.js

@@ -864,9 +864,8 @@
         if (event.target.classList.contains("zen-workspace-empty-space")) {
           dropElement = this._tabbrowserTabs.ariaFocusableItems.at(-1);
           // Only if there are no normal tabs to drop after
-          showIndicatorUnderNewTabButton = !tabs.some(
-            (tab) => !(tab.group || tab).pinned || tab.hasAttribute("zen-essential")
-          );
+          showIndicatorUnderNewTabButton =
+            gBrowser.tabs[gBrowser.tabs.length - 1].hasAttribute("zen-empty-tab");
         } else {
           const numEssentials = gBrowser._numZenEssentials;
           const numPinned = gBrowser.pinnedTabCount - numEssentials;

src/zen/sessionstore/ZenWindowSync.sys.mjs

@@ -802,7 +802,11 @@ class nsZenWindowSync {
     if (aWindow.gBrowser.selectedTab === this.#lastSelectedTab && !ignoreSameTab) {
       return;
     }
-    if (aPreviousTab?._zenContentsVisible) {
+    let activeBrowsers = aWindow.gBrowser.selectedBrowsers;
+    let activeTabs = activeBrowsers.map((browser) => aWindow.gBrowser.getTabForBrowser(browser));
+    // Ignore previous tabs that are still "active". These scenarios could happen for example,
+    // when selecting on a split view tab that was already active.
+    if (aPreviousTab?._zenContentsVisible && !activeTabs.includes(aPreviousTab)) {
       const otherTabToShow = this.#getActiveTabFromOtherWindows(
         aWindow,
         aPreviousTab.id,
@@ -815,8 +819,7 @@ class nsZenWindowSync {
       }
     }
     let promises = [];
-    for (const browserView of aWindow.gBrowser.selectedBrowsers) {
-      const selectedTab = aWindow.gBrowser.getTabForBrowser(browserView);
+    for (const selectedTab of activeTabs) {
       if (selectedTab._zenContentsVisible || selectedTab.hasAttribute("zen-empty-tab")) {
         continue;
       }

src/zen/split-view/ZenViewSplitter.mjs

@@ -2023,24 +2023,15 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
       return;
     }
     this._sessionRestoring = true;
-    let groups = [];
     // We can just get the tab group with document.getElementById(group.groupId)
     // and add the tabs to it
     for (const group of data) {
       const groupElement = document.getElementById(group.groupId);
       if (groupElement) {
         const tabs = groupElement.tabs;
-        groups.push(groupElement);
         this.splitTabs(tabs, group.gridType);
       }
     }
-    // See https://github.com/zen-browser/desktop/issues/11887, some groups
-    // may end up empty after restoring, so we need to remove them
-    for (const groupElement of groups) {
-      if (groupElement.tabs.length === 0) {
-        groupElement.remove();
-      }
-    }
     delete this._sessionRestoring;
   }
 

src/zen/tabs/ZenEssentialsPromo.mjs

@@ -48,9 +48,6 @@ class nsZenEssentialsPromo extends MozXULElement {
  *  "exists" if the promo already exists, or false if the section is not empty.
  */
 export function createZenEssentialsPromo(container = undefined) {
-  if (!Services.prefs.getBoolPref("zen.tabs.essentials.dnd-promo-enabled", true)) {
-    return false;
-  }
   if (container === undefined) {
     container = gZenWorkspaces.getCurrentSpaceContainerId();
   }

src/zen/tabs/zen-essentials-promo.css

@@ -15,9 +15,7 @@ zen-essentials-promo {
   margin: 2px;
   text-align: center;
   box-shadow: 0 0 1px 1px rgba(0, 0, 0, 0.1);
-  transition:
-    background 0.1s,
-    outline 0.1s;
+  transition: background 0.1s;
 
   &:not([dragover="true"]) {
     background: color-mix(in srgb, var(--zen-primary-color) 60%, transparent);

src/zen/tabs/zen-tabs/vertical-tabs.css

@@ -1349,4 +1349,8 @@
   left: 0;
   pointer-events: none;
   background: var(--zen-primary-color);
+
+  :root[zen-right-side="true"] & {
+    left: calc(-1 * var(--zen-toolbox-padding));
+  }
 }