Fix window size after collapsing (broken 376a6a5af0)

imgui.cpp

@@ -3349,7 +3349,7 @@ bool ImGui::Begin(const char* name, bool* p_opened, const ImVec2& size_on_first_
                 if (g.HoveredWindow == window && held && g.IO.MouseDoubleClicked[0])
                 {
                     // Manual auto-fit when double-clicking
-                    window->Size = window->SizeFull = size_auto_fit;
+                    window->SizeFull = size_auto_fit;
                     if (!(window->Flags & ImGuiWindowFlags_NoSavedSettings))
                         MarkSettingsDirty();
                     SetActiveId(0);
@@ -3357,10 +3357,12 @@ bool ImGui::Begin(const char* name, bool* p_opened, const ImVec2& size_on_first_
                 else if (held)
                 {
                     // Resize
-                    window->Size = window->SizeFull = ImMax(window->SizeFull + g.IO.MouseDelta, style.WindowMinSize);
+                    window->SizeFull = ImMax(window->SizeFull + g.IO.MouseDelta, style.WindowMinSize);
                     if (!(window->Flags & ImGuiWindowFlags_NoSavedSettings))
                         MarkSettingsDirty();
                 }
+
+                window->Size = window->SizeFull;
                 title_bar_rect = window->TitleBarRect();
             }