wined3d: Introduce a function for safely releasing a DC.

dlls/wined3d/context.c

@@ -844,25 +844,9 @@ static void context_update_window(struct wined3d_context *context)
             context, context->win_handle, context->swapchain->win_handle);
 
     if (context->valid)
-    {
-        /* You'd figure ReleaseDC() would fail if the DC doesn't match the
-         * window. However, that's not what actually happens, and there are
-         * user32 tests that confirm ReleaseDC() with the wrong window is
-         * supposed to succeed. So explicitly check that the DC belongs to
-         * the window, since we want to avoid releasing a DC that belongs to
-         * some other window if the original window was already destroyed. */
-        if (WindowFromDC(context->hdc) != context->win_handle)
-        {
-            WARN("DC %p does not belong to window %p.\n",
-                    context->hdc, context->win_handle);
-        }
-        else if (!ReleaseDC(context->win_handle, context->hdc))
-        {
-            ERR("Failed to release device context %p, last error %#x.\n",
-                    context->hdc, GetLastError());
-        }
-    }
-    else context->valid = 1;
+        wined3d_release_dc(context->win_handle, context->hdc);
+    else
+        context->valid = 1;
 
     context->win_handle = context->swapchain->win_handle;
 
@@ -987,7 +971,7 @@ static void context_destroy_gl_resources(struct wined3d_context *context)
         ERR("Failed to disable GL context.\n");
     }
 
-    ReleaseDC(context->win_handle, context->hdc);
+    wined3d_release_dc(context->win_handle, context->hdc);
 
     if (!wglDeleteContext(context->glCtx))
     {

dlls/wined3d/directx.c

@@ -277,7 +277,7 @@ static void wined3d_caps_gl_ctx_destroy(const struct wined3d_caps_gl_ctx *ctx)
         ERR("wglDeleteContext(%p) failed, last error %#x.\n", ctx->gl_ctx, err);
     }
 
-    ReleaseDC(ctx->wnd, ctx->dc);
+    wined3d_release_dc(ctx->wnd, ctx->dc);
     DestroyWindow(ctx->wnd);
 
     if (ctx->restore_gl_ctx && !wglMakeCurrent(ctx->restore_dc, ctx->restore_gl_ctx))

dlls/wined3d/swapchain.c

@@ -83,7 +83,7 @@ static void swapchain_cleanup(struct wined3d_swapchain *swapchain)
     {
         TRACE("Destroying backup wined3d window %p, dc %p.\n", swapchain->backup_wnd, swapchain->backup_dc);
 
-        ReleaseDC(swapchain->backup_wnd, swapchain->backup_dc);
+        wined3d_release_dc(swapchain->backup_wnd, swapchain->backup_dc);
         DestroyWindow(swapchain->backup_wnd);
     }
 }

dlls/wined3d/utils.c

@@ -3852,3 +3852,17 @@ void wined3d_ftoa(float value, char *s)
 
     sprintf(s, "%s%d.%08de%+03d", sign, x, frac, exponent);
 }
+
+void wined3d_release_dc(HWND window, HDC dc)
+{
+    /* You'd figure ReleaseDC() would fail if the DC doesn't match the window.
+     * However, that's not what actually happens, and there are user32 tests
+     * that confirm ReleaseDC() with the wrong window is supposed to succeed.
+     * So explicitly check that the DC belongs to the window, since we want to
+     * avoid releasing a DC that belongs to some other window if the original
+     * window was already destroyed. */
+    if (WindowFromDC(dc) != window)
+        WARN("DC %p does not belong to window %p.\n", dc, window);
+    else if (!ReleaseDC(window, dc))
+        ERR("Failed to release device context %p, last error %#x.\n", dc, GetLastError());
+}

dlls/wined3d/wined3d_private.h

@@ -2742,6 +2742,8 @@ void multiply_matrix(struct wined3d_matrix *dest, const struct wined3d_matrix *s
 UINT wined3d_log2i(UINT32 x) DECLSPEC_HIDDEN;
 unsigned int count_bits(unsigned int mask) DECLSPEC_HIDDEN;
 
+void wined3d_release_dc(HWND window, HDC dc) DECLSPEC_HIDDEN;
+
 struct wined3d_shader_lconst
 {
     struct list entry;