# HG changeset patch
# User Bram Moolenaar <Bram@vim.org>
# Date 1652212802 -7200
# Node ID 4c749f9b97fd0a52c2387b9cc2410df3c3f129b4
# Parent  08e9b779b21304f7a8b47df40b6239569afd55eb
patch 8.2.4936: MS-Windows: mouse coordinates for scroll event are wrong

Commit: https://github.com/vim/vim/commit/a773d84570e224035389f6697ac5634d7f27cccc
Author: LemonBoy <thatlemon@gmail.com>
Date:   Tue May 10 20:54:46 2022 +0100

    patch 8.2.4936: MS-Windows: mouse coordinates for scroll event are wrong

    Problem:    MS-Windows: mouse coordinates for scroll event are wrong.
    Solution:   Convert coordinates to the text area coordinates. (closes https://github.com/vim/vim/issues/10400)

diff --git a/src/gui_w32.c b/src/gui_w32.c
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -4146,15 +4146,16 @@ init_mouse_wheel(void)
 }
 
 /*
- * Intellimouse wheel handler.
- * Treat a mouse wheel event as if it were a scroll request.
+ * Mouse scroll event handler.
  */
     static void
-_OnMouseWheel(HWND hwnd, short zDelta, LPARAM param, int horizontal)
+_OnMouseWheel(HWND hwnd, WPARAM wParam, LPARAM lParam, int horizontal)
 {
     int		button;
     win_T	*wp;
     int		modifiers, kbd_modifiers;
+    int		zDelta = GET_WHEEL_DELTA_WPARAM(wParam);
+    POINT	pt;
 
     wp = gui_mouse_window(FIND_POPUP);
 
@@ -4207,11 +4208,12 @@ init_mouse_wheel(void)
     if ((kbd_modifiers & MOD_MASK_ALT) != 0)
 	modifiers |= MOUSE_ALT;
 
-    mch_disable_flush();
-    gui_send_mouse_event(button, GET_X_LPARAM(param), GET_Y_LPARAM(param),
-		FALSE, kbd_modifiers);
-    mch_enable_flush();
-    gui_may_flush();
+    // The cursor position is relative to the upper-left corner of the screen.
+    pt.x = GET_X_LPARAM(lParam);
+    pt.y = GET_Y_LPARAM(lParam);
+    ScreenToClient(s_textArea, &pt);
+
+    gui_send_mouse_event(button, pt.x, pt.y, FALSE, kbd_modifiers);
 }
 
 #ifdef USE_SYSMENU_FONT
@@ -4663,8 +4665,8 @@ destroy_sizing_tip(void)
     WPARAM wParam,
     LPARAM lParam)
 {
-    // TRACE("WndProc: hwnd = %08x, msg = %x, wParam = %x, lParam = %x\n",
-    //       hwnd, uMsg, wParam, lParam);
+    // ch_log(NULL, "WndProc: hwnd = %08x, msg = %x, wParam = %x, lParam = %x",
+	    // hwnd, uMsg, wParam, lParam);
 
     HandleMouseHide(uMsg, lParam);
 
@@ -4763,7 +4765,7 @@ destroy_sizing_tip(void)
 
     case WM_MOUSEWHEEL:
     case WM_MOUSEHWHEEL:
-	_OnMouseWheel(hwnd, HIWORD(wParam), lParam, uMsg == WM_MOUSEHWHEEL);
+	_OnMouseWheel(hwnd, wParam, lParam, uMsg == WM_MOUSEHWHEEL);
 	return 0L;
 
 	// Notification for change in SystemParametersInfo()
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4936,
+/**/
     4935,
 /**/
     4934,