patch 8.1.0839: when using VTP wrong colors after a color scheme change

Problem:    When using VTP wrong colors after a color scheme change.
Solution:   When VTP is active always clear after a color scheme change.
            (Nobuhiro Takasaki, closes #3872)

src/ex_docmd.c

@@ -7211,6 +7211,15 @@ ex_colorscheme(exarg_T *eap)
     }
     else if (load_colors(eap->arg) == FAIL)
 	semsg(_("E185: Cannot find color scheme '%s'"), eap->arg);
+
+#ifdef FEAT_VTP
+    else if (has_vtp_working())
+    {
+	// background color change requires clear + redraw
+	update_screen(CLEAR);
+	redrawcmd();
+    }
+#endif
 }
 
     static void

src/version.c

@@ -783,6 +783,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    839,
 /**/
     838,
 /**/