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

[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 );
```