[PATCH 0/1] MR7766: win32u: Preserve result string from multiple WINE_IME_POST_UPDATE call during ImeProcessKey.

[Byeongsik Jeon (＠bsjeon)]

In winemac.drv, Multiple ime update calls occur during ImeProcessKey.
These multiple ime update calls need to be properly merged into ‘data->update’.
However, currently win32u/imm.c::post_ime_update() only keeps the last ime
update call.

Valid rules are:
 - The comp_str is discarded when the next ime update call occurs,
   so it is only valid when the last ime update call has the comp_str.
 - The result_str is retained even if the next ime update call occurs.
 - If the next ime update call has the result_str, it is appended after
   the previous result_str. (e.g. 'r-k-1' or 'r-k-<SPACE>')

Test key sequences are:
 - "Japanese Romanji" : 'nihongo-<SPACE>-n'
 - "Korean 2-Set Keyboard" :  'r-k-s-k'
 - "Korean 2-Set Keyboard" : 'r-k-1" or 'r-k-<SPACE>'

[PATCH 1/1] win32u: Preserve result string from multiple WINE_IME_POST_UPDATE call during ImeProcessKey.

[Byeongsik Jeon]

From: Byeongsik Jeon

In winemac.drv, Multiple ime update calls occur during ImeProcessKey.
These multiple ime update calls need to be properly merged into ‘data->update’.
However, currently win32u/imm.c::post_ime_update() only keeps the last ime
update call.

Valid rules are:
 - The comp_str is discarded when the next ime update call occurs,
   so it is only valid when the last ime update call has the comp_str.
 - The result_str is retained even if the next ime update call occurs.
 - If the next ime update call has the result_str, it is appended after
   the previous result_str. (e.g. 'r-k-1' or 'r-k-<SPACE>')

Test key sequences are:
 - "Japanese Romanji" : 'nihongo-<SPACE>-n'
 - "Korean 2-Set Keyboard" :  'r-k-s-k'
 - "Korean 2-Set Keyboard" : 'r-k-1" or 'r-k-<SPACE>'
---
 dlls/win32u/imm.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/dlls/win32u/imm.c b/dlls/win32u/imm.c
index 99dc3e5e225..f673693f6a0 100644
--- a/dlls/win32u/imm.c
+++ b/dlls/win32u/imm.c
@@ -442,6 +442,8 @@ static void post_ime_update( HWND hwnd, UINT cursor_pos, WCHAR *comp_str, WCHAR
     struct imm_thread_data *data = get_imm_thread_data();
     UINT id = -1, comp_len, result_len;
     struct ime_update *update;
+    WCHAR *prev_result_str = NULL;
+    UINT prev_result_len = 0;

TRACE( "hwnd %p, cursor_pos %u, comp_str %s, result_str %s\n", hwnd, cursor_pos,
            debugstr_w(comp_str), debugstr_w(result_str) );
@@ -449,10 +451,23 @@ static void post_ime_update( HWND hwnd, UINT cursor_pos, WCHAR *comp_str, WCHAR
     comp_len = comp_str ? wcslen( comp_str ) + 1 : 0;
     result_len = result_str ? wcslen( result_str ) + 1 : 0;

-    if (!(update = malloc( offsetof(struct ime_update, buffer[comp_len + result_len]) ))) return;
+    if (data->ime_process_vkey && data->update && data->update->result_str)
+    {
+        prev_result_str = data->update->result_str;
+        prev_result_len = result_len ? wcslen( prev_result_str )
+                                     : prev_result_str ? wcslen( prev_result_str ) + 1 : 0;
+    }
+
+    if (!(update = malloc( offsetof(struct ime_update,
+                                    buffer[comp_len + prev_result_len + result_len]) ))) return;
     update->cursor_pos = cursor_pos;
     update->comp_str = comp_str ? memcpy( update->buffer, comp_str, comp_len * sizeof(WCHAR) ) : NULL;
-    update->result_str = result_str ? memcpy( update->buffer + comp_len, result_str, result_len * sizeof(WCHAR) ) : NULL;
+    update->result_str = result_str ? memcpy( update->buffer + comp_len + prev_result_len,
+                                              result_str, result_len * sizeof(WCHAR) )
+                                    : NULL;
+    if (prev_result_len)
+        update->result_str = memcpy( update->buffer + comp_len,
+                                     prev_result_str, prev_result_len * sizeof(WCHAR) );

if (!(update->vkey = data->ime_process_vkey))
     {

[Rémi Bernon (＠rbernon)]

Rémi Bernon (@rbernon) commented about dlls/win32u/imm.c:
>      update->scan = data->ime_process_scan;
>      free( data->update );
>      data->update = update;
>  }

I think this loses the previous result if it was != NULL but the new update has result_str == NULL. What about:

```suggestion:-45+0
    struct imm_thread_data *data = get_imm_thread_data();
    UINT id = -1, comp_len, result_len, prev_result_len;
    WCHAR *prev_result_str, *tmp;
    struct ime_update *update;

TRACE( "hwnd %p, cursor_pos %u, comp_str %s, result_str %s\n", hwnd, cursor_pos,
           debugstr_w(comp_str), debugstr_w(result_str) );

comp_len = comp_str ? wcslen( comp_str ) + 1 : 0;
    result_len = result_str ? wcslen( result_str ) + 1 : 0;

/* prepend or keep the previous result string, if there was any */
    if (!data->ime_process_vkey || !data->update) prev_result_str = NULL;
    else prev_result_str = data->update->result_str;
    prev_result_len = prev_result_str ? wcslen( prev_result_str ) + 1 : 0;

if (!prev_result_len && !result_len) tmp = NULL;
    else if (!(tmp = malloc( (prev_result_len + result_len) * sizeof(WCHAR) ))) return;

if (prev_result_len && result_len) prev_result_len -= 1; /* concat both strings */
    if (prev_result_len) memcpy( tmp, prev_result_str, prev_result_len * sizeof(WCHAR) );
    if (result_len) memcpy( tmp + prev_result_len, result_str, result_len * sizeof(WCHAR) );
    result_len += prev_result_len;
    result_str = tmp;

if (!(update = malloc( offsetof(struct ime_update, buffer[comp_len + result_len]) ))) return;
    update->cursor_pos = cursor_pos;
    update->comp_str = comp_str ? memcpy( update->buffer, comp_str, comp_len * sizeof(WCHAR) ) : NULL;
    update->result_str = result_str ? memcpy( update->buffer + comp_len, result_str, result_len * sizeof(WCHAR) ) : NULL;

if (!(update->vkey = data->ime_process_vkey))
    {
        pthread_mutex_lock( &imm_mutex );
        id = update->scan = ++ime_update_count;
        update->vkey = VK_PROCESSKEY;
        list_add_tail( &ime_updates, &update->entry );
        pthread_mutex_unlock( &imm_mutex );

NtUserPostMessage( hwnd, WM_WINE_IME_NOTIFY, IMN_WINE_SET_COMP_STRING, id );
    }
    else
    {
        update->scan = data->ime_process_scan;
        free( data->update );
        data->update = update;
    }

free( result_str );
```