patch 9.2.0414: Flicker when drawing window separator and pum is shown

Problem:  In a vertical split where the pum overlaps the windows vsep column,
          background draws (vsep at cursor row, status line,
          redraw_vseps, idle ins_redraw) can write into cells that are
          covered by the pum, because skip_for_popup() only protects
          those cells while pum_will_redraw is set.
Solution: In skip_for_popup(), also skip cells under a visible pum when
          the current draw is not the pum itself (screen_zindex
          POPUPMENU_ZINDEX).  Exclude the wildmenu pum (MODE_CMDLINE):
          while the cmdline grows, pum_row is briefly stale and
          protecting those cells would blank a cell of the wrapped
          cmdline row (Yasuhiro Matsumoto).

closes: #20093

Signed-off-by: Yasuhiro Matsumoto <mattn.jp@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/screen.c

@@ -445,6 +445,21 @@ skip_for_popup(int row, int col)
 #endif
 	    )
 	return TRUE;
+    // Protect cells under the pum from background draws (vsep, status line).
+    // Excluded for wildmenu pum (MODE_CMDLINE): pum_row can be stale while
+    // the cmdline grows.
+#ifdef FEAT_PROP_POPUP
+    if (screen_zindex < POPUPMENU_ZINDEX
+	    && pum_visible()
+	    && (State & MODE_CMDLINE) == 0
+	    && pum_under_menu(row, col, FALSE))
+	return TRUE;
+#else
+    if (pum_visible()
+	    && (State & MODE_CMDLINE) == 0
+	    && pum_under_menu(row, col, FALSE))
+	return TRUE;
+#endif
 #ifdef FEAT_PROP_POPUP
     if (blocked_by_popup(row, col))
 	return TRUE;

src/version.c

@@ -729,6 +729,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    414,
 /**/
     413,
 /**/