patch 8.1.2254: MS-Windows: mouse scroll wheel doesn't work in popup
Problem: MS-Windows: mouse scroll wheel doesn't work in popup.
Solution: Handle mouse wheel events separately. (closes #5138)
diff --git a/src/proto/gui.pro b/src/proto/gui.pro
index 2dc09a1..a49ecad 100644
--- a/src/proto/gui.pro
+++ b/src/proto/gui.pro
@@ -52,6 +52,7 @@
void gui_new_scrollbar_colors(void);
void gui_focus_change(int in_focus);
void gui_mouse_moved(int x, int y);
+win_T *gui_mouse_window(mouse_find_T popup);
void gui_mouse_correct(void);
void ex_gui(exarg_T *eap);
int gui_find_bitmap(char_u *name, char_u *buffer, char *ext);