Tables, Menus: Fixed using BeginTable() in menu layer (any menu bar). (ocornut#8355)

Author: ocornut

docs/CHANGELOG.txt

@@ -71,6 +71,9 @@ Other changes:
   scrollbar when using thick border sizes. (#8267, #7887)
 - Windows: Fixed IsItemXXXX() functions not working on append-version of EndChild(). (#8350)
   Also made some of the fields accessible after BeginChild() to match Begin() logic.
+- Tables, Menus: Fixed using BeginTable() in menu layer (any menu bar). (#8355)
+  It previously overrode the current layer back to main layer, which caused an issue
+  with MainMenuBar attempted to release focus when leaving the menu layer.
 - ColorEdit, ColorPicker: Fixed alpha preview broken in 1.91.7. (#8336, #8241). [@PathogenDavid]
 - Tabs, Style: reworked selected overline rendering to better accommodate
   for rounded tabs. Reduced default thickness (style.TabBarOverlineSize),

imgui_internal.h

@@ -2877,6 +2877,7 @@ struct IMGUI_API ImGuiTable
     ImGuiTableDrawChannelIdx    DummyDrawChannel;           // Redirect non-visible columns here.
     ImGuiTableDrawChannelIdx    Bg2DrawChannelCurrent;      // For Selectable() and other widgets drawing across columns after the freezing line. Index within DrawSplitter.Channels[]
     ImGuiTableDrawChannelIdx    Bg2DrawChannelUnfrozen;
+    ImS8                        NavLayer;                   // ImGuiNavLayer at the time of BeginTable().
     bool                        IsLayoutLocked;             // Set by TableUpdateLayout() which is called when beginning the first row.
     bool                        IsInsideRow;                // Set when inside TableBeginRow()/TableEndRow().
     bool                        IsInitializing;

imgui_tables.cpp

@@ -374,6 +374,7 @@ bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImG
     table->ColumnsCount = columns_count;
     table->IsLayoutLocked = false;
     table->InnerWidth = inner_width;
+    table->NavLayer = (ImS8)outer_window->DC.NavLayerCurrent;
     temp_data->UserOuterSize = outer_size;
 
     // Instance data (for instance 0, TableID == TableInstanceID)
@@ -1050,7 +1051,8 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
         const int column_n = table->DisplayOrderToIndex[order_n];
         ImGuiTableColumn* column = &table->Columns[column_n];
 
-        column->NavLayerCurrent = (ImS8)(table->FreezeRowsCount > 0 ? ImGuiNavLayer_Menu : ImGuiNavLayer_Main); // Use Count NOT request so Header line changes layer when frozen
+        // Initial nav layer: using FreezeRowsCount, NOT FreezeRowsRequest, so Header line changes layer when frozen
+        column->NavLayerCurrent = (ImS8)(table->FreezeRowsCount > 0 ? ImGuiNavLayer_Menu : table->NavLayer);
 
         if (offset_x_frozen && table->FreezeColumnsCount == visible_n)
         {
@@ -1493,7 +1495,7 @@ void    ImGui::EndTable()
     if (inner_window != outer_window)
     {
         short backup_nav_layers_active_mask = inner_window->DC.NavLayersActiveMask;
-        inner_window->DC.NavLayersActiveMask |= 1 << ImGuiNavLayer_Main; // So empty table don't appear to navigate differently.
+        inner_window->DC.NavLayersActiveMask |= 1 << table->NavLayer; // So empty table don't appear to navigate differently.
         g.CurrentTable = NULL; // To avoid error recovery recursing
         EndChild();
         g.CurrentTable = table;
@@ -2032,7 +2034,7 @@ void ImGui::TableEndRow(ImGuiTable* table)
     if (unfreeze_rows_request)
     {
         for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
-            table->Columns[column_n].NavLayerCurrent = ImGuiNavLayer_Main;
+            table->Columns[column_n].NavLayerCurrent = table->NavLayer;
         const float y0 = ImMax(table->RowPosY2 + 1, table->InnerClipRect.Min.y);
         table_instance->LastFrozenHeight = y0 - table->OuterRect.Min.y;