IO: do not disable io.ConfigWindowsResizeFromEdges when ImGuiBackendFlags_HasMouseCursors is not set by backend.

Amend 42bf149ac

docs/CHANGELOG.txt

@@ -46,6 +46,12 @@ Breaking changes:
 
 Other changes:
 
+- IO: do not disable io.ConfigWindowsResizeFromEdges (which allow resizing from borders
+  and lower-left corner) when ImGuiBackendFlags_HasMouseCursors is not set by backend.
+  The initial reasoning is that resizing from borders feels better when correct mouse cursor
+  shape change as honored by backends. Keeping this enabling will hopefully increase pressure
+  on third-party backends to set ImGuiBackendFlags_HasMouseCursors and honor changes of
+  ImGui::GetMouseCursor() value. (#1495)
 - Examples: GLFW+Vulkan, SDL+Vulkan: handle swap chain resize even without Vulkan
   returning VK_SUBOPTIMAL_KHR, which doesn't seem to happen on Wayland. (#7671)
   [@AndreiNego, @ocornut]

imgui.cpp

@@ -9919,10 +9919,6 @@ static void ImGui::ErrorCheckNewFrameSanityChecks()
     if ((g.IO.ConfigFlags & ImGuiConfigFlags_NavEnableKeyboard) && g.IO.BackendUsingLegacyKeyArrays == 1)
         IM_ASSERT(g.IO.KeyMap[ImGuiKey_Space] != -1 && "ImGuiKey_Space is not mapped, required for keyboard navigation.");
 #endif
-
-    // Check: the io.ConfigWindowsResizeFromEdges option requires backend to honor mouse cursor changes and set the ImGuiBackendFlags_HasMouseCursors flag accordingly.
-    if (g.IO.ConfigWindowsResizeFromEdges && !(g.IO.BackendFlags & ImGuiBackendFlags_HasMouseCursors))
-        g.IO.ConfigWindowsResizeFromEdges = false;
 }
 
 static void ImGui::ErrorCheckEndFrameSanityChecks()