[PATCH v3 4/5] winex11: Avoid breaking XIM XFilterEvent / XmbLookupString sequence.

[Rémi Bernon]

From: Rémi Bernon

By only delaying ConfigureNotify events for merging, and report empty
composition string when result string is committed.

Based on a patch from Byeong-Sik Jeon .

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55027
---
 dlls/winex11.drv/event.c | 70 ++++++++++++----------------------------
 dlls/winex11.drv/xim.c   |  2 +-
 2 files changed, 21 insertions(+), 51 deletions(-)

diff --git a/dlls/winex11.drv/event.c b/dlls/winex11.drv/event.c
index f364cdbe715..3ba6589d2cf 100644
--- a/dlls/winex11.drv/event.c
+++ b/dlls/winex11.drv/event.c
@@ -255,44 +255,6 @@ static Bool filter_event( Display *display, XEvent *event, char *arg )
     }
 }

-
-enum event_merge_action
-{
-    MERGE_DISCARD,  /* discard the old event */
-    MERGE_HANDLE,   /* handle the old event */
-    MERGE_KEEP,     /* keep the old event for future merging */
-    MERGE_IGNORE    /* ignore the new event, keep the old one */
-};
-
-/***********************************************************************
- *           merge_events
- *
- * Try to merge 2 consecutive events.
- */
-static enum event_merge_action merge_events( XEvent *prev, XEvent *next )
-{
-    switch (prev->type)
-    {
-    case ConfigureNotify:
-        switch (next->type)
-        {
-        case ConfigureNotify:
-            if (prev->xany.window == next->xany.window)
-            {
-                TRACE( "discarding duplicate ConfigureNotify for window %lx\n", prev->xany.window );
-                return MERGE_DISCARD;
-            }
-            break;
-        case Expose:
-        case PropertyNotify:
-            return MERGE_KEEP;
-        }
-        break;
-    }
-    return MERGE_HANDLE;
-}
-
-
 /***********************************************************************
  *           call_event_handler
  */
@@ -339,7 +301,6 @@ static BOOL process_events( Display *display, Bool (*filter)(Display*, XEvent*,X
     XEvent event, prev_event;
     int count = 0;
     BOOL queued = FALSE;
-    enum event_merge_action action = MERGE_DISCARD;

prev_event.type = 0;
     while (XCheckIfEvent( display, &event, filter, (char *)arg ))
@@ -375,20 +336,29 @@ static BOOL process_events( Display *display, Bool (*filter)(Display*, XEvent*,X
             else
                 continue;  /* filtered, ignore it */
         }
-        if (prev_event.type) action = merge_events( &prev_event, &event );
-        switch( action )
+
+        /* delay and merge consecutive ConfigureNotify events */
+        if (event.type == ConfigureNotify && prev_event.type == ConfigureNotify)
         {
-        case MERGE_HANDLE:  /* handle prev, keep new */
-            queued |= call_event_handler( display, &prev_event );
-            /* fall through */
-        case MERGE_DISCARD:  /* discard prev, keep new */
+            if (prev_event.xany.window != event.xany.window) queued |= call_event_handler( display, &prev_event );
+            else TRACE( "discarding duplicate ConfigureNotify for window %lx\n", prev_event.xany.window );
             prev_event = event;
-            break;
-        case MERGE_KEEP:  /* handle new, keep prev for future merging */
+        }
+        else if (event.type == ConfigureNotify)
+        {
+            TRACE( "delaying ConfigureNotify event for future merging\n" );
+            prev_event = event;
+        }
+        else
+        {
+            /* allow merging over PropertyNotify and Expose events */
+            if (event.type != PropertyNotify && event.type != Expose)
+            {
+                if (prev_event.type) call_event_handler( display, &prev_event );
+                prev_event.type = 0;
+            }
+
             queued |= call_event_handler( display, &event );
-            /* fall through */
-        case MERGE_IGNORE: /* ignore new, keep prev for future merging */
-            break;
         }
     }
     if (prev_event.type) queued |= call_event_handler( display, &prev_event );
diff --git a/dlls/winex11.drv/xim.c b/dlls/winex11.drv/xim.c
index 1c3d2dd9875..1b063cfe886 100644
--- a/dlls/winex11.drv/xim.c
+++ b/dlls/winex11.drv/xim.c
@@ -140,7 +140,7 @@ void xim_set_result_string( HWND hwnd, const char *str, UINT count )
     len = ntdll_umbstowcs( str, count, output, count );
     output[len] = 0;

-    post_ime_update( hwnd, 0, ime_comp_buf, output );
+    post_ime_update( hwnd, 0, NULL, output );

free( output );
 }