Docking: Fixed an issue leading to incorrect restoration of selected tab in dock nodes that don't carry the currently focused window. (#2304)

In TestSuite: see "docking_tab_focus_restore".
Remove old code ~ ed3c015f 8bac6d4 8cac70d8
+ Fix potential crash in IMGUI_DEBUG_LOG_DOCKING() path when using amended buttons.

docs/CHANGELOG.txt

@@ -102,6 +102,8 @@ Other changes:
 
 Docking+Viewports Branch:
 
+- Docking: Fixed an issue leading to incorrect restoration of selected tab in dock nodes that
+  don't carry the currently focused window. (#2304)
 - Docking: added ImGuiDockNodeFlags_NoUndocking. (#2999, #6823, #6780, #3492)
 - Docking: renamed ImGuiDockNodeFlags_NoSplit to ImGuiDockNodeFlags_NoDockingSplit.
 - Docking: renamed ImGuiDockNodeFlags_NoDockingInCentralNode to ImGuiDockNodeFlags_NoDockingOverCentralNode.

imgui.cpp

@@ -7635,8 +7635,9 @@ void ImGui::FocusWindow(ImGuiWindow* window, ImGuiFocusRequestFlags flags)
     window->LastFrameJustFocused = g.FrameCount;
 
     // Select in dock node
-    if (dock_node && dock_node->TabBar)
-        dock_node->TabBar->SelectedTabId = dock_node->TabBar->NextSelectedTabId = window->TabId;
+    // For #2304 we avoid applying focus immediately before the tabbar is visible.
+    //if (dock_node && dock_node->TabBar)
+    //    dock_node->TabBar->SelectedTabId = dock_node->TabBar->NextSelectedTabId = window->TabId;
 
     // Bring to front
     BringWindowToFocusFront(focus_front_window);
@@ -16841,7 +16842,11 @@ static void ImGui::DockNodeUpdateTabBar(ImGuiDockNode* node, ImGuiWindow* host_w
     {
         IMGUI_DEBUG_LOG_DOCKING("[docking] In node 0x%08X: %d new appearing tabs:%s\n", node->ID, tab_bar->Tabs.Size - tabs_unsorted_start, (tab_bar->Tabs.Size > tabs_unsorted_start + 1) ? " (will sort)" : "");
         for (int tab_n = tabs_unsorted_start; tab_n < tab_bar->Tabs.Size; tab_n++)
-            IMGUI_DEBUG_LOG_DOCKING("[docking] - Tab '%s' Order %d\n", tab_bar->Tabs[tab_n].Window->Name, tab_bar->Tabs[tab_n].Window->DockOrder);
+        {
+            ImGuiTabItem* tab = &tab_bar->Tabs[tab_n];
+            IMGUI_DEBUG_LOG_DOCKING("[docking] - Tab 0x%08X '%s' Order %d\n", tab->ID, TabBarGetTabName(tab_bar, tab), tab->Window ? tab->Window->DockOrder : -1);
+        }
+        IMGUI_DEBUG_LOG_DOCKING("[docking] SelectedTabId = 0x%08X, NavWindow->TabId = 0x%08X\n", node->SelectedTabId, g.NavWindow ? g.NavWindow->TabId : -1);
         if (tab_bar->Tabs.Size > tabs_unsorted_start + 1)
             ImQsort(tab_bar->Tabs.Data + tabs_unsorted_start, tab_bar->Tabs.Size - tabs_unsorted_start, sizeof(ImGuiTabItem), TabItemComparerByDockOrder);
     }