[PATCH 0/1] MR2001: Draft: riched20: Obtain the composition start index after deleting selection.

[Jinoh Kang (＠iamahuman)]

Today, the Rich Edit control handles the WM_IME_STARTCOMPOSITION message
by the computing the composition start position (imeStartIndex) _before_
calling ME_DeleteSelection(), which shifts the character positions after
the range of deletion.  If the selection were not empty, imeStartIndex
immediately becomes stale, since it does not take into account the
number of deleted characters before it.

Fix this by computing imeStartIndex after the ME_DeleteSelection() call.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54318

cc/ @aricstewart (has no Developer access to wine/wine; cannot be assigned as a reviewer yet)

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/2001

[PATCH 1/1] riched20: Obtain the composition start index after deleting selection.

[Jinoh Kang]

From: Jinoh Kang <jinoh.kang.kr(a)gmail.com>

Today, the Rich Edit control handles the WM_IME_STARTCOMPOSITION message
by the computing the composition start position (imeStartIndex) _before_
calling ME_DeleteSelection(), which shifts the character positions after
the range of deletion.  If the selection were not empty, imeStartIndex
immediately becomes stale, since it does not take into account the
number of deleted characters before it.

Fix this by computing imeStartIndex after the ME_DeleteSelection() call.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54318
---
 dlls/riched20/editor.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dlls/riched20/editor.c b/dlls/riched20/editor.c
index 57601745ab2..b4fd474ff87 100644
--- a/dlls/riched20/editor.c
+++ b/dlls/riched20/editor.c
@@ -4099,8 +4099,8 @@ LRESULT editor_handle_message( ME_TextEditor *editor, UINT msg, WPARAM wParam,
     return 0;
   case WM_IME_STARTCOMPOSITION:
   {
-    editor->imeStartIndex=ME_GetCursorOfs(&editor->pCursors[0]);
     ME_DeleteSelection(editor);
+    editor->imeStartIndex=ME_GetCursorOfs(&editor->pCursors[0]);
     ME_CommitUndo(editor);
     ME_UpdateRepaint(editor, FALSE);
     return 0;
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/2001

[Huw Davies (＠huw)]

Huw Davies (@huw) commented about dlls/riched20/editor.c:
> return 0;
>    case WM_IME_STARTCOMPOSITION:
>    {
> -    editor->imeStartIndex=ME_GetCursorOfs(&editor->pCursors[0]);
>      ME_DeleteSelection(editor);
> +    editor->imeStartIndex=ME_GetCursorOfs(&editor->pCursors[0]);

This looks fine to go in after 8.0.  Minor nit, could you add spaces on either side of the `=`?

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/2001#note_21426