[PATCH v2 0/1] MR303: win32u: Don't report cloned monitors in EnumDisplayMonitors().

[Arek Hiler (＠ivyl)]

Based on:
ca39b1c22dfa ("user32: Don't report mirrored slave monitors in EnumDisplayMonitors.")
2affb854e524 ("user32: Change slave to a more neutral word.")

Which seems to got lost during:
318673405c62 ("win32u: Move NtUserEnumDisplayMonitors implementation from user32.")

Fixes regression with Elite Dangerous launcher freezing when cloned
displays are present.

Signed-off-by: Arkadiusz Hiler

CC: @zhiyi @jacek

--
  v2: win32u: Don't report cloned monitors in EnumDisplayMonitors().

https://gitlab.winehq.org/wine/wine/-/merge_requests/303

[PATCH v2 1/1] win32u: Don't report cloned monitors in EnumDisplayMonitors().

[Arkadiusz Hiler]

From: Arkadiusz Hiler

Based on:
ca39b1c22dfa ("user32: Don't report mirrored slave monitors in EnumDisplayMonitors.")
2affb854e524 ("user32: Change slave to a more neutral word.")

Which seems to got lost during:
318673405c62 ("win32u: Move NtUserEnumDisplayMonitors implementation from user32.")

Fixes regression with Elite Dangerous launcher freezing when cloned
displays are present.

Signed-off-by: Arkadiusz Hiler 
---
 dlls/win32u/sysparams.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/dlls/win32u/sysparams.c b/dlls/win32u/sysparams.c
index a8c1d977c7d..0a9cb76cb6d 100644
--- a/dlls/win32u/sysparams.c
+++ b/dlls/win32u/sysparams.c
@@ -1249,9 +1249,10 @@ static BOOL update_display_cache_from_registry(void)
     DWORD adapter_id, monitor_id, monitor_count = 0, size;
     KEY_BASIC_INFORMATION key;
     struct adapter *adapter;
-    struct monitor *monitor;
+    struct monitor *monitor, *monitor2;
     HANDLE mutex = NULL;
     NTSTATUS status;
+    BOOL is_cloned;
     BOOL ret;

/* If user driver did initialize the registry, then exit */
@@ -1295,6 +1296,22 @@ static BOOL update_display_cache_from_registry(void)
                 break;
             }

+            is_cloned = FALSE;
+            LIST_FOR_EACH_ENTRY(monitor2, &monitors, struct monitor, entry)
+            {
+                if (EqualRect(&monitor2->rc_monitor, &monitor->rc_monitor))
+                {
+                    is_cloned = TRUE;
+                    break;
+                }
+            }
+
+            if (is_cloned)
+            {
+                free( monitor );
+                continue;
+            }
+
             monitor->handle = UlongToHandle( ++monitor_count );
             list_add_tail( &monitors, &monitor->entry );
         }

[PATCH v2 0/1] MR303: win32u: Don't report cloned monitors in EnumDisplayMonitors(). - approved

[Zhiyi Zhang (＠zhiyi)]

This merge request was approved by Zhiyi Zhang.

[Jacek Caban (＠jacek)]

Jacek Caban (@jacek) commented about dlls/win32u/sysparams.c:
> -
>        is_cloned = FALSE;
> -
>        LIST_FOR_EACH_ENTRY(monitor2, &monitors, struct monitor, entry)
> -
>        {
> -
>            if (EqualRect(&monitor2->rc_monitor, &monitor->rc_monitor))
> -
>            {
> -
>                is_cloned = TRUE;
> -
>                break;
> -
>            }
> -
>        }
> -
> -
>        if (is_cloned)
> -
>        {
> -
>            free( monitor );
> -
>            continue;
> -
>        }

We will eventually want to move QueryDisplayConfig to win32u as well and it will need to be aware of mirrored monitors, so I think it's better to have them in the list. Note that most places should already handle that fine. I think it would be better to have a flag in monitor struct and skip mirrored monitors during monitor enumeration when appropriate.