[PATCH 0/1] MR7827: imm32: Fix the WM_IME_COMPOSITION messages to be between the WM_IME_{START|END}COMPOSITION message.

[Byeongsik Jeon (＠bsjeon)]

This patch fixes a Japanese input issue in MS Office Visual Basic and Mery text
editor ime inline mode. The following was considered:

1. Japanese ime: the result string message is always placed between
     WM_IME_STARTCOMPOSITION and WM_IME_ENDCOMPOSITION. Currently in Wine,
     the result string message follows WM_IME_ENDCOMPOSITION.

dlls/imm32/tests/imm32.c::test_nihongo_no().

2. Chinese ime: same as Japanese ime.

3. Korean ime: mostly the same, but there are some cases where it is not
     (e.g. CPS_COMPLETE, 'r-k-RETURN'). However, I haven't found any problem
     even if it behave like Japanese ime message order.

3. zero-length preedit string: as in MR !3115 commit d1f9aae, the message
     followed by WM_IME_ENDCOMPOSITION. Currently in Wine, it is associated
     with WM_IME_STARTCOMPOSITION.

4. zero-length result string: ignore.

[PATCH 1/1] imm32: Fix the WM_IME_COMPOSITION messages to be between the WM_IME_{START|END}COMPOSITION message.

[Byeongsik Jeon]

From: Byeongsik Jeon

This patch fixes a Japanese input issue in MS Office Visual Basic and Mery text
editor ime inline mode. The following was considered:

1. Japanese ime: the result string message is always placed between
     WM_IME_STARTCOMPOSITION and WM_IME_ENDCOMPOSITION. Currently in Wine,
     the result string message follows WM_IME_ENDCOMPOSITION.

dlls/imm32/tests/imm32.c::test_nihongo_no().

2. Chinese ime: same as Japanese ime.

3. Korean ime: mostly the same, but there are some cases where it is not
     (e.g. CPS_COMPLETE, 'r-k-RETURN'). However, I haven't found any problem
     even if it behave like Japanese ime message order.

3. zero-length preedit string: as in MR !3115 commit d1f9aae, the message
     followed by WM_IME_ENDCOMPOSITION. Currently in Wine, it is associated
     with WM_IME_STARTCOMPOSITION.

4. zero-length result string: ignore.
---
 dlls/imm32/ime.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/dlls/imm32/ime.c b/dlls/imm32/ime.c
index d7ffc3de115..5d4c92f99c9 100644
--- a/dlls/imm32/ime.c
+++ b/dlls/imm32/ime.c
@@ -561,14 +561,17 @@ UINT WINAPI ImeToAsciiEx( UINT vkey, UINT vsc, BYTE *state, TRANSMSGLIST *msgs,
     if (status) WARN( "WINE_IME_TO_ASCII_EX returned status %#lx\n", status );
     else
     {
-        TRANSMSG status_msg = {.message = ime_set_composition_status( himc, !!compstr->dwCompStrOffset )};
-        if (status_msg.message) msgs->TransMsg[count++] = status_msg;
+        if (compstr->dwCompStrLen || compstr->dwResultStrLen)
+        {
+            TRANSMSG msg = {.message = ime_set_composition_status( himc, TRUE )};
+            if (msg.message == WM_IME_STARTCOMPOSITION) msgs->TransMsg[count++] = msg;
+        }

-        if (compstr->dwResultStrOffset)
+        if (compstr->dwResultStrLen)
         {
             const WCHAR *result = (WCHAR *)((BYTE *)compstr + compstr->dwResultStrOffset);
             TRANSMSG msg = {.message = WM_IME_COMPOSITION, .wParam = result[0], .lParam = GCS_RESULTSTR};
-            if (compstr->dwResultClauseOffset) msg.lParam |= GCS_RESULTCLAUSE;
+            if (compstr->dwResultClauseLen) msg.lParam |= GCS_RESULTCLAUSE;
             msgs->TransMsg[count++] = msg;
         }

@@ -582,6 +585,12 @@ UINT WINAPI ImeToAsciiEx( UINT vkey, UINT vsc, BYTE *state, TRANSMSGLIST *msgs,
             msgs->TransMsg[count++] = msg;
         }

+        if (!compstr->dwCompStrLen)
+        {
+            TRANSMSG msg = {.message = ime_set_composition_status( himc, FALSE )};
+            if (msg.message == WM_IME_ENDCOMPOSITION) msgs->TransMsg[count++] = msg;
+        }
+
         if (!key_consumed)
         {
             TRANSMSG msg = {.message = WM_IME_KEYDOWN, .wParam = vkey, .lParam = vsc};

[Byeongsik Jeon (＠bsjeon)]

To switch on ime inline mode in [Mery](https://www.haijin-boys.com/software/mery/mery-3-7-0#41) text editor, press "Alt+t-o" and tick "変換中の文字列を挿入モードで入力する".

![mery_ime_inline_mode](/uploads/e4f492b4a5c9b5683237d89e9ffaa4cd/mery_ime_inline_mode.png)

[Rémi Bernon (＠rbernon)]

Rémi Bernon (@rbernon) commented about dlls/imm32/ime.c:
> -
>    {
> -
>        TRANSMSG msg = {.message = ime_set_composition_status( himc, TRUE )};
> -
>        if (msg.message == WM_IME_STARTCOMPOSITION) msgs->TransMsg[count++] = msg;
> -
>    }
>
> -
>    if (compstr->dwResultStrOffset)
> -
>    if (compstr->dwResultStrLen)
>    {
>        const WCHAR *result = (WCHAR *)((BYTE *)compstr + compstr->dwResultStrOffset);
>        TRANSMSG msg = {.message = WM_IME_COMPOSITION, .wParam = result[0], .lParam = GCS_RESULTSTR};
> -
>        if (compstr->dwResultClauseOffset) msg.lParam |= GCS_RESULTCLAUSE;
> -
>        if (compstr->dwResultClauseLen) msg.lParam |= GCS_RESULTCLAUSE;
>        msgs->TransMsg[count++] = msg;
>    }
>
>    if (compstr->dwCompStrOffset)

Shouldn't this be changed to dwCompStrLen as well to match the if on line [564](https://gitlab.winehq.org/wine/wine/-/merge_requests/7827/diffs?commit_id=74...) (and [588](https://gitlab.winehq.org/wine/wine/-/merge_requests/7827/diffs?commit_id=74...) changed to an else)?

Otherwise if dwCompStrOffset > 0 and dwCompStrLen == 0 we could send an (empty) WM_IME_COMPOSITION message outside of WM_IME_STARTCOMPOSITION/WM_IME_STARTCOMPOSITION? It's purely hypothetical as I don't think it's possible, but I think it's good to keep the conditions consistent.

[Byeongsik Jeon (＠bsjeon)]

On Wed Apr 16 08:13:29 2025 +0000, Rémi Bernon wrote:
> Shouldn't this be changed to dwCompStrLen as well to match the if on
> line
> [564](https://gitlab.winehq.org/wine/wine/-/merge_requests/7827/diffs?commit_id=74...)
> (and
> [588](https://gitlab.winehq.org/wine/wine/-/merge_requests/7827/diffs?commit_id=74...)
> changed to an else)?
> Otherwise if dwCompStrOffset > 0 and dwCompStrLen == 0 we could send an
> (empty) WM_IME_COMPOSITION message outside of
> WM_IME_STARTCOMPOSITION/WM_IME_STARTCOMPOSITION? It's purely
> hypothetical as I don't think it's possible, but I think it's good to
> keep the conditions consistent.

Yes. This is possible if we handle the empty WM_IME_COMPOSITION handling in the WM_IME_ENDCOMPOSITION part.

As in d1f9aae5, the empty WM_IME_COMPOSITION is wparam==0x1b, lparam==0x1bf, but I left the code in because it was ambiguous.

If ime_to_tascii_ex doesn't update 'compstr' for empty string, I think it should be fine for lparam==0x1lbf.

[Rémi Bernon (＠rbernon)]

On Wed Apr 16 09:04:11 2025 +0000, Byeongsik Jeon wrote:
> Yes. This is possible if we handle the empty WM_IME_COMPOSITION handling
> in the WM_IME_ENDCOMPOSITION part.
> As in d1f9aae5, the empty WM_IME_COMPOSITION is wparam==0x1b,
> lparam==0x1bf, but I left the code in because it was ambiguous.
> If ime_to_tascii_ex doesn't update 'compstr' for empty string, I think
> it should be fine for lparam==0x1lbf.

Hmm... Then maybe we should check for dwCompStrOffset instead of dwCompStrLen when sending WM_IME_STARTCOMPOSITION/WM_IME_ENDCOMPOSITION on lines 564 and 588?