From f1749b0808c66a0341b77409cc9338ab5624a04c Mon Sep 17 00:00:00 2001
From: Jacek Caban <jacek@codeweavers.com>
Date: Fri, 4 Aug 2023 13:11:50 +0200
Subject: [PATCH] win32u: Pack input param for CB_GETCOMBOBOXINFO message.

Based on patch by Tim Clem.
---
 dlls/win32u/message.c      | 10 ++++++++--
 dlls/win32u/tests/win32u.c | 18 +++++++++++-------
 dlls/wow64win/user.c       | 16 ++++++++++++++++
 3 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/dlls/win32u/message.c b/dlls/win32u/message.c
index 71c1017a3f0..d15f9af3f9f 100644
--- a/dlls/win32u/message.c
+++ b/dlls/win32u/message.c
@@ -1843,8 +1843,14 @@ void pack_user_message( void *buffer, size_t size, UINT message,
         return;
     }
     case CB_GETCOMBOBOXINFO:
-        memset( buffer, 0, size );
-        return;
+        if (sizeof(void *) == 4)
+        {
+            COMBOBOXINFO *cbi = buffer;
+            memcpy( cbi, lparam_ptr, sizeof(*cbi) );
+            cbi->cbSize = sizeof(*cbi);
+            return;
+        }
+        break;
     }
 
     if (size) memcpy( buffer, lparam_ptr, size );
diff --git a/dlls/win32u/tests/win32u.c b/dlls/win32u/tests/win32u.c
index beb2050c695..25358c5d0d8 100644
--- a/dlls/win32u/tests/win32u.c
+++ b/dlls/win32u/tests/win32u.c
@@ -1362,7 +1362,7 @@ struct lparam_hook_test
     const void *lparam;
     const void *change_lparam;
     const void *check_lparam;
-    const void *default_lparam;
+    const void *in_lparam;
     size_t lparam_size;
     size_t lparam_init_size;
     size_t check_size;
@@ -1425,10 +1425,12 @@ static void check_params( const struct lparam_hook_test *test, UINT message,
     default:
         if (test->check_size) {
             const void *expected;
-            if (is_ret && test->change_lparam)
+            if (is_ret && test->check_lparam)
+                expected = test->check_lparam;
+            else if (is_ret && test->change_lparam)
                 expected = test->change_lparam;
-            else if (test->default_lparam)
-                expected = test->default_lparam;
+            else if (test->in_lparam)
+                expected = test->in_lparam;
             else
                 expected = test->lparam;
             ok( !memcmp( (const void *)lparam, expected, test->check_size ), "unexpected lparam content\n" );
@@ -1686,7 +1688,9 @@ static void test_wndproc_hook(void)
     static const MDINEXTMENU nm_in = { .hmenuIn = (HMENU)0xdeadbeef };
     static const MDINEXTMENU nm_out = { .hmenuIn = (HMENU)1 };
     static const MDICREATESTRUCTW mcs_in = { .x = 1, .y = 2 };
-    static const COMBOBOXINFO cbi_in = {};
+    static const COMBOBOXINFO cbi_in = { .cbSize = 1, .hwndList = HWND_MESSAGE };
+    static const COMBOBOXINFO cbi_check =
+        { .cbSize = sizeof(void *) == 4 ? sizeof(cbi_in) : 1, .hwndList = HWND_MESSAGE };
     static const COMBOBOXINFO cbi_out = { .hwndList = (HWND)2 };
     static const COMBOBOXINFO cbi_ret = { .hwndList = (HWND)2,
         .cbSize = sizeof(void *) == 4 ? sizeof(cbi_in) : 0 };
@@ -1920,8 +1924,8 @@ static void test_wndproc_hook(void)
         },
         {
             "CB_GETCOMBOBOXINFO", CB_GETCOMBOBOXINFO,
-            .lparam_size = sizeof(cbi_in), .change_lparam = &cbi_out, .default_lparam = &cbi_in,
-            .check_lparam = &cbi_ret,
+            .lparam_size = sizeof(cbi_in), .change_lparam = &cbi_out, .lparam = &cbi_in,
+            .check_lparam = &cbi_ret, .check_size = sizeof(cbi_in), .in_lparam = &cbi_check,
         },
         /* messages that don't change lparam */
         { "WM_USER", WM_USER },
diff --git a/dlls/wow64win/user.c b/dlls/wow64win/user.c
index b15f0a263cf..07143b78195 100644
--- a/dlls/wow64win/user.c
+++ b/dlls/wow64win/user.c
@@ -802,6 +802,22 @@ static size_t packed_message_64to32( UINT message, WPARAM wparam,
             memcpy( params32, &mcs32, sizeof(mcs32) );
             return sizeof(mcs32) + size;
         }
+
+    case CB_GETCOMBOBOXINFO:
+        {
+            COMBOBOXINFO32 ci32;
+            const COMBOBOXINFO *ci64 = params64;
+
+            ci32.cbSize      = sizeof(ci32);
+            ci32.rcItem      = ci64->rcItem;
+            ci32.rcButton    = ci64->rcButton;
+            ci32.stateButton = ci64->stateButton;
+            ci32.hwndCombo   = HandleToLong( ci64->hwndCombo );
+            ci32.hwndItem    = HandleToLong( ci64->hwndItem );
+            ci32.hwndList    = HandleToLong( ci64->hwndList );
+            memcpy( params32, &ci32, sizeof(ci32) );
+            return sizeof(ci32);
+        }
     }
 
     memmove( params32, params64, size );