[PATCH v2 2/2] winex11: handle fallback display modes when XRandR fails

[Wei Xie]

From: Wei Xie

1. Added fallback logic to use default display dimensions when XRandR
fails to provide screen sizes
2. Implemented default mode creation with standard 60Hz refresh rate
3. Added proper error handling for memory allocation failures
4. Maintains compatibility with systems where XRandR extension is not
available

The reason for the problem is that in scenes where the monitor is not connected,
xrandr does not get connected display
---
 dlls/winex11.drv/xrandr.c | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/dlls/winex11.drv/xrandr.c b/dlls/winex11.drv/xrandr.c
index 979cbc8645f..a794d1be0f9 100644
--- a/dlls/winex11.drv/xrandr.c
+++ b/dlls/winex11.drv/xrandr.c
@@ -267,8 +267,35 @@ static BOOL xrandr10_get_modes( x11drv_settings_id id, DWORD flags, DEVMODEW **n
     short *rates;

sizes = pXRRSizes( gdi_display, DefaultScreen( gdi_display ), &size_count );
+    /* 如果没有获取到屏幕大小,尝试使用默认屏幕大小 */
     if (size_count <= 0)
+    {
+        INT width = DisplayWidth(gdi_display, DefaultScreen(gdi_display));
+        INT height = DisplayHeight(gdi_display, DefaultScreen(gdi_display));
+
+        if (width > 0 && height > 0)
+        {
+            /* 使用默认屏幕大小创建一个模式 */
+            mode_count = 1;
+            modes = calloc(mode_count * DEPTH_COUNT, sizeof(*modes) + sizeof(SizeID));
+            if (!modes)
+            {
+                RtlSetLastWin32Error(ERROR_NOT_ENOUGH_MEMORY);
+                return FALSE;
+            }
+
+            for (depth_idx = 0, mode = modes; depth_idx < DEPTH_COUNT; ++depth_idx)
+            {
+                add_xrandr10_mode(mode, depths[depth_idx], width, height, 0, 0, full);
+                mode = NEXT_DEVMODEW(mode);
+            }
+
+            *new_modes = modes;
+            *new_mode_count = mode_count * DEPTH_COUNT;
+            return TRUE;
+        }
         return FALSE;
+    }

for (size_idx = 0; size_idx < size_count; ++size_idx)
     {
@@ -350,7 +377,13 @@ static BOOL xrandr10_get_current_mode( x11drv_settings_id id, DEVMODEW *mode )

sizes = pXRRSizes( gdi_display, DefaultScreen( gdi_display ), &size_count );
     if (size_count <= 0)
-        return FALSE;
+    {
+        mode->dmBitsPerPel = screen_bpp;
+        mode->dmPelsWidth = DisplayWidth(gdi_display, DefaultScreen(gdi_display));
+        mode->dmPelsHeight = DisplayHeight(gdi_display, DefaultScreen(gdi_display));
+        mode->dmDisplayFrequency = 60;
+        return TRUE;
+    }

screen_config = pXRRGetScreenInfo( gdi_display, DefaultRootWindow( gdi_display ) );
     size_id = pXRRConfigCurrentConfiguration( screen_config, &rotation );