From a5c909221e3c17b59271f3d3cd50b151ae565232 Mon Sep 17 00:00:00 2001
From: Jacek Caban <jacek@codeweavers.com>
Date: Tue, 18 Jul 2023 20:17:36 +0200
Subject: [PATCH] win32u: Use user message packing for EM_GETLINE.

---
 dlls/user32/winproc.c      | 11 ++---------
 dlls/win32u/message.c      | 26 ++++++++++++++++++++------
 dlls/win32u/tests/win32u.c | 18 ++++++++++++++++++
 dlls/wow64win/user.c       |  1 +
 4 files changed, 41 insertions(+), 15 deletions(-)

diff --git a/dlls/user32/winproc.c b/dlls/user32/winproc.c
index 5d0e4eb5205..202c955e152 100644
--- a/dlls/user32/winproc.c
+++ b/dlls/user32/winproc.c
@@ -874,16 +874,8 @@ BOOL unpack_message( HWND hwnd, UINT message, WPARAM *wparam, LPARAM *lparam,
     case CB_GETDROPPEDCONTROLRECT:
     case EM_SETRECT:
     case EM_SETRECTNP:
-        break;
     case EM_GETLINE:
-    {
-        WORD len;
-        if (size < sizeof(WORD)) return FALSE;
-        len = *(WORD *)*buffer;
-        if (!get_buffer_space( buffer, (len + 1) * sizeof(WCHAR), size )) return FALSE;
-        *lparam = (LPARAM)*buffer + sizeof(WORD);  /* don't erase WORD at start of buffer */
-        return TRUE;
-    }
+        break;
     case EM_SETTABSTOPS:
     case LB_SETTABSTOPS:
         if (!*wparam) return TRUE;
@@ -1090,6 +1082,7 @@ BOOL WINAPI User32CallWindowProc( struct win_proc_params *params, ULONG size )
         case CB_GETDROPPEDCONTROLRECT:
         case EM_SETRECT:
         case EM_SETRECTNP:
+        case EM_GETLINE:
         {
             LRESULT *result_ptr = (LRESULT *)buffer - 1;
             *result_ptr = result;
diff --git a/dlls/win32u/message.c b/dlls/win32u/message.c
index cb6dac39bb6..d37b05ca1eb 100644
--- a/dlls/win32u/message.c
+++ b/dlls/win32u/message.c
@@ -583,6 +583,17 @@ static BOOL unpack_message( HWND hwnd, UINT message, WPARAM *wparam, LPARAM *lpa
     case EM_SETRECTNP:
         minsize = sizeof(RECT);
         break;
+    case EM_GETLINE:
+    {
+        WORD *len_ptr, len;
+        if (size < sizeof(WORD)) return FALSE;
+        len = *(WORD *)*buffer;
+        if (!get_buffer_space( buffer, (len + 1) * sizeof(WCHAR), size )) return FALSE;
+        len_ptr = *buffer;
+        len_ptr[0] = len_ptr[1] = len;
+        *lparam = (LPARAM)(len_ptr + 1);
+        return TRUE;
+    }
     case WM_WINE_SETWINDOWPOS:
     {
         WINDOWPOS wp;
@@ -1396,6 +1407,9 @@ size_t user_message_size( UINT message, WPARAM wparam, LPARAM lparam, BOOL other
     case EM_SETRECTNP:
         size = sizeof(RECT);
         break;
+    case EM_GETLINE:
+        size = max( *(WORD *)lparam * char_size( ansi ), sizeof(WORD) );
+        break;
     }
 
     return size;
@@ -1461,6 +1475,9 @@ void pack_user_message( void *buffer, size_t size, UINT message,
     case EM_GETRECT:
     case CB_GETDROPPEDCONTROLRECT:
         return;
+    case EM_GETLINE:
+        size = sizeof(WORD);
+        break;
     }
 
     if (size) memcpy( buffer, lparam_ptr, size );
@@ -1556,6 +1573,9 @@ static void copy_user_result( void *buffer, size_t size, LRESULT result, UINT me
     case CB_GETDROPPEDCONTROLRECT:
         copy_size = sizeof(RECT);
         break;
+    case EM_GETLINE:
+        copy_size = string_size( buffer, ansi );
+        break;
     default:
         return;
     }
@@ -1587,12 +1607,6 @@ static void copy_reply( LRESULT result, HWND hwnd, UINT message, WPARAM wparam,
     case WM_MOVING:
         copy_size = sizeof(RECT);
         break;
-    case EM_GETLINE:
-    {
-        WORD *ptr = (WORD *)lparam;
-        copy_size = ptr[-1] * sizeof(WCHAR);
-        break;
-    }
     case LB_GETSELITEMS:
         copy_size = wparam * sizeof(UINT);
         break;
diff --git a/dlls/win32u/tests/win32u.c b/dlls/win32u/tests/win32u.c
index 5ff755745f1..4d88eeaee8b 100644
--- a/dlls/win32u/tests/win32u.c
+++ b/dlls/win32u/tests/win32u.c
@@ -1413,6 +1413,14 @@ static void check_params( const struct lparam_hook_test *test, UINT message,
         ok( wparam, "wparam = 0\n" );
         break;
 
+    case EM_GETLINE:
+        if (!is_ret)
+        {
+            WCHAR *buf = (WCHAR *)lparam;
+            ok(buf[0] == 8, "buf[0] = %x\n", buf[0]);
+        }
+        break;
+
     default:
         if (test->check_size) {
             const void *expected = is_ret && test->change_lparam ? test->change_lparam : test->lparam;
@@ -1867,6 +1875,16 @@ static void test_wndproc_hook(void)
             .lparam_size = sizeof(DWORD), .lparam = &dw_in, .change_lparam = &dw_out,
             .check_size = sizeof(DWORD),
         },
+        {
+            "EM_GETLINE", EM_GETLINE, .msg_result = 5,
+            .lparam = L"\x8""2345678", .lparam_size = sizeof(strbufW), .change_lparam = L"abc\0defg",
+            .check_size = sizeof(WCHAR), .check_lparam = L"abc\0""5678",
+        },
+        {
+            "EM_GETLINE-2", EM_GETLINE, .msg_result = 1,
+            .lparam = L"\x8""2345678", .lparam_size = sizeof(strbufW), .change_lparam = L"abc\0defg",
+            .check_size = sizeof(WCHAR), .check_lparam = L"abc\0""5678",
+        },
         /* messages that don't change lparam */
         { "WM_USER", WM_USER },
         { "WM_NOTIFY", WM_NOTIFY },
diff --git a/dlls/wow64win/user.c b/dlls/wow64win/user.c
index 37cb0caeae9..14b76649709 100644
--- a/dlls/wow64win/user.c
+++ b/dlls/wow64win/user.c
@@ -843,6 +843,7 @@ static size_t packed_result_32to64( UINT message, WPARAM wparam, const void *par
     case EM_SETRECTNP:
     case LB_GETITEMRECT:
     case CB_GETDROPPEDCONTROLRECT:
+    case EM_GETLINE:
         break;
 
     default: