Windows: BeginChild(): fixed being unable to combine manual resize on one axis and automatic resize on the other axis. (#8690)

+ removed obsolete TODO entries.

docs/CHANGELOG.txt

@@ -309,6 +309,10 @@ Other changes:
 - Windows: loosened code to allow hovering of resize grips, borders, and table
   borders while hovering a sibling child window, so that the code in master matches
   one in docking (they accidentally diverged). (#8554)
+- Windows: BeginChild(): fixed being unable to combine manual resize on one axis
+  and automatic resize on the other axis. (#8690)
+  e.g. neither ImGuiChildFlags_ResizeX | ImGuiChildFlags_AutoResizeY 
+            or ImGuiChildFlags_ResizeY | ImGuiChildFlags_AutoResizeX worked before.
 - TreeNode: added experimental flags to draw tree hierarchy outlines linking
   parent and tree nodes: (#2920)
   - ImGuiTreeNodeFlags_DrawLinesNone: No lines drawn (default value in style.TreeLinesFlags).

docs/TODO.txt

@@ -26,9 +26,6 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - window/size: manually triggered auto-fit (double-click on grip) shouldn't resize window down to viewport size?
  - window/size: how to allow to e.g. auto-size vertically to fit contents, but be horizontally resizable? Assuming SetNextWindowSize() is modified to treat -1.0f on each axis as "keep as-is" (would be good but might break erroneous code): Problem is UpdateWindowManualResize() and lots of code treat (window->AutoFitFramesX > 0 || window->AutoFitFramesY > 0) together.
  - window/opt: freeze window flag: if not focused/hovered, return false, render with previous ImDrawList. and/or reduce refresh rate. -> this may require enforcing that it is illegal to submit contents if Begin returns false.
- - window/child: background options for child windows, border option (disable rounding).
- - window/child: allow resizing of child windows (possibly given min/max for each axis?.)
- - window/child: allow SetNextWindowContentSize() to work on child windows.
  - window/clipping: some form of clipping when DisplaySize (or corresponding viewport) is zero.
  - window/tabbing: add a way to signify that a window or docked window requires attention (e.g. blinking title bar, trying to click behind a modal).
  - window/id_stack: add e.g. window->GetIDFromPath() with support for leading / and ../ (#1390, #331) -> model from test engine.

imgui.cpp

@@ -6612,9 +6612,9 @@ static ImVec2 CalcWindowAutoFitSize(ImGuiWindow* window, const ImVec2& size_cont
         // FIXME: CalcWindowAutoFitSize() doesn't take into account that only one axis may be auto-fit when calculating scrollbars,
         // we may need to compute/store three variants of size_auto_fit, for x/y/xy.
         // Here we implement a workaround for child windows only, but a full solution would apply to normal windows as well:
-        if ((window->ChildFlags & ImGuiChildFlags_ResizeX) && !(window->ChildFlags & ImGuiChildFlags_ResizeY))
+        if ((window->ChildFlags & ImGuiChildFlags_ResizeX) && !(window->ChildFlags & (ImGuiChildFlags_ResizeY | ImGuiChildFlags_AutoResizeY)))
             size_auto_fit.y = window->SizeFull.y;
-        else if (!(window->ChildFlags & ImGuiChildFlags_ResizeX) && (window->ChildFlags & ImGuiChildFlags_ResizeY))
+        else if ((window->ChildFlags & ImGuiChildFlags_ResizeY) && !(window->ChildFlags & (ImGuiChildFlags_ResizeX | ImGuiChildFlags_AutoResizeX)))
             size_auto_fit.x = window->SizeFull.x;
 
         // When the window cannot fit all contents (either because of constraints, either because screen is too small),
@@ -6734,7 +6734,9 @@ static int ImGui::UpdateWindowManualResize(ImGuiWindow* window, const ImVec2& si
     ImGuiContext& g = *GImGui;
     ImGuiWindowFlags flags = window->Flags;
 
-    if ((flags & ImGuiWindowFlags_NoResize) || (flags & ImGuiWindowFlags_AlwaysAutoResize) || window->AutoFitFramesX > 0 || window->AutoFitFramesY > 0)
+    if ((flags & ImGuiWindowFlags_NoResize) || window->AutoFitFramesX > 0 || window->AutoFitFramesY > 0)
+        return false;
+    if ((flags & ImGuiWindowFlags_AlwaysAutoResize) && (window->ChildFlags & (ImGuiChildFlags_ResizeX | ImGuiChildFlags_ResizeY)) == 0)
         return false;
     if (window->WasActive == false) // Early out to avoid running this code for e.g. a hidden implicit/fallback Debug window.
         return false;