Docking: DockSpace() returns its node ID + adding branch changelog.

docs/CHANGELOG.txt

@@ -126,6 +126,15 @@ Other Changes:
 - Examples: Vulkan: Rebuild swapchain on VK_SUBOPTIMAL_KHR. (#3881)
 - Docs: Improvements to minor mistakes in documentation comments (#3923) [@ANF-Studios]
 
+Docking Branch:
+
+- Docking: DockSpace() returns its node ID.
+- Docking: Dockspace() never draws a background. (#3924)
+- Docking: undocking nodes/windows covering most of the monitor max their size down to 90% to ease further manipulations.
+- Viewports: Hotfix for crash in monitor array access, caused by 4b9bc4902. (#3967)
+- Backends, Viewports: GLFW: Add a workaround for stuck keys after closing a GLFW window (#3837).
+- Backends, Viewports: Vulkan: Rebuild swapchain on VK_SUBOPTIMAL_KHR. (#3881)
+
 
 -----------------------------------------------------------------------
  VERSION 1.82 (Released 2021-02-15)

imgui.cpp

@@ -14730,13 +14730,13 @@ void ImGui::SetWindowDock(ImGuiWindow* window, ImGuiID dock_id, ImGuiCond cond)
 // Create an explicit dockspace node within an existing window. Also expose dock node flags and creates a CentralNode by default.
 // The Central Node is always displayed even when empty and shrink/extend according to the requested size of its neighbors.
 // DockSpace() needs to be submitted _before_ any window they can host. If you use a dockspace, submit it early in your app.
-void ImGui::DockSpace(ImGuiID id, const ImVec2& size_arg, ImGuiDockNodeFlags flags, const ImGuiWindowClass* window_class)
+ImGuiID ImGui::DockSpace(ImGuiID id, const ImVec2& size_arg, ImGuiDockNodeFlags flags, const ImGuiWindowClass* window_class)
 {
     ImGuiContext* ctx = GImGui;
     ImGuiContext& g = *ctx;
     ImGuiWindow* window = GetCurrentWindow();
     if (!(g.IO.ConfigFlags & ImGuiConfigFlags_DockingEnable))
-        return;
+        return 0;
 
     // Early out if parent window is hidden/collapsed
     // This is faster but also DockNodeUpdateTabBar() relies on TabBarLayout() running (which won't if SkipItems=true) to set NextSelectedTabId = 0). See #2960.
@@ -14764,7 +14764,7 @@ void ImGui::DockSpace(ImGuiID id, const ImVec2& size_arg, ImGuiDockNodeFlags fla
     {
         IM_ASSERT(node->IsDockSpace() == false && "Cannot call DockSpace() twice a frame with the same ID");
         node->LocalFlags |= ImGuiDockNodeFlags_DockSpace;
-        return;
+        return id;
     }
     node->LocalFlags |= ImGuiDockNodeFlags_DockSpace;
 
@@ -14772,7 +14772,7 @@ void ImGui::DockSpace(ImGuiID id, const ImVec2& size_arg, ImGuiDockNodeFlags fla
     if (flags & ImGuiDockNodeFlags_KeepAliveOnly)
     {
         node->LastFrameAlive = g.FrameCount;
-        return;
+        return id;
     }
 
     const ImVec2 content_avail = GetContentRegionAvail();
@@ -14825,6 +14825,7 @@ void ImGui::DockSpace(ImGuiID id, const ImVec2& size_arg, ImGuiDockNodeFlags fla
 
     End();
     ItemSize(size);
+    return id;
 }
 
 // Tips: Use with ImGuiDockNodeFlags_PassthruCentralNode!

imgui.h

@@ -764,7 +764,7 @@ namespace ImGui
     // About DockSpace:
     // - Use DockSpace() to create an explicit dock node _within_ an existing window. See Docking demo for details.
     // - DockSpace() needs to be submitted _before_ any window they can host. If you use a dockspace, submit it early in your app.
-    IMGUI_API void          DockSpace(ImGuiID id, const ImVec2& size = ImVec2(0, 0), ImGuiDockNodeFlags flags = 0, const ImGuiWindowClass* window_class = NULL);
+    IMGUI_API ImGuiID       DockSpace(ImGuiID id, const ImVec2& size = ImVec2(0, 0), ImGuiDockNodeFlags flags = 0, const ImGuiWindowClass* window_class = NULL);
     IMGUI_API ImGuiID       DockSpaceOverViewport(const ImGuiViewport* viewport = NULL, ImGuiDockNodeFlags flags = 0, const ImGuiWindowClass* window_class = NULL);
     IMGUI_API void          SetNextWindowDockID(ImGuiID dock_id, ImGuiCond cond = 0);           // set next window dock id (FIXME-DOCK)
     IMGUI_API void          SetNextWindowClass(const ImGuiWindowClass* window_class);           // set next window class (rare/advanced uses: provide hints to the platform backend via altered viewport flags and parent/child info)