Backends: SDL: Amend 08350e5, multi-viewports mouse tracking works under Linux. (#4960) + Reword tests to help static analysis.

backends/imgui_impl_sdl.cpp

@@ -370,7 +370,7 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, void* sdl_gl_context)
         io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;  // We can create multi-viewports on the Platform side (optional)
 
     // SDL on Linux/OSX doesn't report events for unfocused windows (see https://github.com/ocornut/imgui/issues/4960)
-#ifdef _WIN32
+#ifndef __APPLE__
     if (mouse_can_use_global_state)
         io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport;// We can call io.AddMouseViewportEvent() with correct data (optional)
 #endif

imgui.cpp

@@ -6383,11 +6383,10 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
             BeginDocked(window, p_open);
             flags = window->Flags;
             if (window->DockIsActive)
+            {
                 IM_ASSERT(window->DockNode != NULL);
-
-            // Docking currently override constraints
-            if (window->DockIsActive)
-                g.NextWindowData.Flags &= ~ImGuiNextWindowDataFlags_HasSizeConstraint;
+                g.NextWindowData.Flags &= ~ImGuiNextWindowDataFlags_HasSizeConstraint; // Docking currently override constraints
+            }
 
             // Amend the Appearing flag
             if (window->DockTabIsVisible && !dock_tab_was_visible && dock_node_was_visible && !window->Appearing && !window_was_appearing)