From 644bf48b6cc4e41f62f39adecd877b0d248e9cab Mon Sep 17 00:00:00 2001
From: "mr. m" <91018726+mr-cheffy@users.noreply.github.com>
Date: Mon, 14 Sep 2026 20:56:36 +0200
Subject: [PATCH] gh-13196: Fixed sidebar not hiding if the urlbar is open
 (gh-15403)

---
 src/zen/common/modules/ZenUIManager.mjs         |  9 +--------
 src/zen/common/styles/zen-browser-container.css |  2 +-
 src/zen/common/styles/zen-browser-ui.css        |  4 ++--
 src/zen/common/styles/zen-theme.css             |  2 +-
 src/zen/compact-mode/ZenCompactMode.mjs         | 10 +++++-----
 src/zen/drag-and-drop/ZenDragAndDrop.js         |  8 +++++++-
 6 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/src/zen/common/modules/ZenUIManager.mjs b/src/zen/common/modules/ZenUIManager.mjs
index 9d6a829f2..98ba56e20 100644
--- a/src/zen/common/modules/ZenUIManager.mjs
+++ b/src/zen/common/modules/ZenUIManager.mjs
@@ -990,14 +990,7 @@ window.gZenVerticalTabsManager = {
     });
 
     ChromeUtils.defineLazyGetter(this, "hidesTabsToolbar", () => {
-      return (
-        document.documentElement
-          .getAttribute("chromehidden")
-          ?.includes("toolbar") ||
-        document.documentElement
-          .getAttribute("chromehidden")
-          ?.includes("menubar")
-      );
+      return document.documentElement.hasAttribute("popup-window");
     });
 
     XPCOMUtils.defineLazyPreferenceGetter(
diff --git a/src/zen/common/styles/zen-browser-container.css b/src/zen/common/styles/zen-browser-container.css
index 78db52f6b..534a3dd2e 100644
--- a/src/zen/common/styles/zen-browser-container.css
+++ b/src/zen/common/styles/zen-browser-container.css
@@ -3,7 +3,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
-:root:not([inDOMFullscreen="true"]):not([chromehidden~="location"]):not([chromehidden~="toolbar"]) {
+:root:not([inDOMFullscreen="true"]):not([popup-window]) {
   & #tabbrowser-tabbox #tabbrowser-tabpanels .browserSidebarContainer {
     --zen-transparent-browser-background: light-dark(rgba(255, 255, 255, 0.6), rgba(255, 255, 255, 0.1));
     overflow: clip;
diff --git a/src/zen/common/styles/zen-browser-ui.css b/src/zen/common/styles/zen-browser-ui.css
index 7308f9e58..9d3201960 100644
--- a/src/zen/common/styles/zen-browser-ui.css
+++ b/src/zen/common/styles/zen-browser-ui.css
@@ -20,7 +20,7 @@ body,
   position: inherit;
 }
 
-:root:is([inDOMFullscreen="true"], [chromehidden~="location"], [chromehidden~="toolbar"]) {
+:root:is([inDOMFullscreen="true"], [popup-window]) {
   #navigator-toolbox,
   #zen-sidebar-splitter {
     visibility: collapse;
@@ -170,7 +170,7 @@ body,
   min-width: 1px;
 }
 
-:root:not([inDOMFullscreen="true"]):not([chromehidden~="location"]):not([chromehidden~="toolbar"]) {
+:root:not([inDOMFullscreen="true"]):not([popup-window]) {
   & #zen-tabbox-wrapper {
     margin: var(--zen-element-separation);
     margin-top: 0;
diff --git a/src/zen/common/styles/zen-theme.css b/src/zen/common/styles/zen-theme.css
index b252a263c..f478aef1f 100644
--- a/src/zen/common/styles/zen-theme.css
+++ b/src/zen/common/styles/zen-theme.css
@@ -303,7 +303,7 @@
   }
 }
 
-#main-window[windowtype="navigator:browser"]:not([chromehidden~='toolbar']) {
+#main-window[windowtype="navigator:browser"]:not([popup-window]) {
   min-height: 495px !important;
 
   @media (-moz-windows-mica) or (-moz-platform: macos) or ((-moz-platform: linux) and
diff --git a/src/zen/compact-mode/ZenCompactMode.mjs b/src/zen/compact-mode/ZenCompactMode.mjs
index 72b897db5..56ffcc956 100644
--- a/src/zen/compact-mode/ZenCompactMode.mjs
+++ b/src/zen/compact-mode/ZenCompactMode.mjs
@@ -165,9 +165,7 @@ window.gZenCompactModeManager = {
   },
 
   get shouldBeCompact() {
-    return !document.documentElement
-      .getAttribute("chromehidden")
-      ?.includes("toolbar");
+    return !document.documentElement.hasAttribute("popup-window");
   },
 
   set preference(value) {
@@ -864,7 +862,6 @@ window.gZenCompactModeManager = {
               "supress-primary-adjustment"
             ) === "true" &&
               gZenVerticalTabsManager._hasSetSingleToolbar) ||
-            this._hasHoveredUrlbar ||
             this._ignoreNextHover ||
             (event.type === "dragleave" &&
               event.explicitOriginalTarget !== target &&
@@ -877,7 +874,10 @@ window.gZenCompactModeManager = {
             return;
           }
 
-          if (this.hoverableElements[i].keepHoverDuration) {
+          if (
+            this.hoverableElements[i].keepHoverDuration &&
+            !this._hasHoveredUrlbar
+          ) {
             this.flashElement(
               target,
               this.hoverableElements[i].keepHoverDuration,
diff --git a/src/zen/drag-and-drop/ZenDragAndDrop.js b/src/zen/drag-and-drop/ZenDragAndDrop.js
index b66dd9331..b73499014 100644
--- a/src/zen/drag-and-drop/ZenDragAndDrop.js
+++ b/src/zen/drag-and-drop/ZenDragAndDrop.js
@@ -1040,12 +1040,16 @@
       }
       this.clearSpaceSwitchTimer();
       gZenFolders.highlightGroupOnDragOver(null);
+      // A drop into a split merges the tab away; nothing lands on it.
+      const toSplit = !!this.#dragOverSplit.canDrop;
       super.handle_drop(event);
       this.#maybeClearVerticalPinnedGridDragOver();
       this.#handle_dropSwitchSpace(event);
       this.#handle_dropCreateSplit(event);
       this._clearDragOverSplit();
-      this.#landDragImage(event);
+      if (!toSplit) {
+        this.#landDragImage(event);
+      }
     }
 
     /**
@@ -1130,6 +1134,7 @@
       );
     }
 
+    // eslint-disable-next-line complexity
     handle_drop_transition(dropElement, draggedTab, movingTabs, dropBefore) {
       if (
         dropElement?.hasAttribute("zen-empty-tab") &&
@@ -1155,6 +1160,7 @@
       try {
         if (
           this.#isAnimatingTabMove ||
+          this.#dragOverSplit.canDrop ||
           !gZenStartup.isReady ||
           gReduceMotion ||
           !dropElement ||