From a0ac2a5d6352510d50016747124c113fece937cb Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Thu, 22 May 2025 07:46:38 +0000
Subject: [PATCH] When there are more than two horizontal windows and the
 active window is in not on an edge, correctly highlight both its left and
 right borders. GitHub issue 4513 from Michael Grant.

---
 screen-redraw.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/screen-redraw.c b/screen-redraw.c
index fb530007..3f339443 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -121,7 +121,12 @@ screen_redraw_pane_border(struct screen_redraw_ctx *ctx, struct window_pane *wp,
 	u_int		 ex = wp->xoff + wp->sx, ey = wp->yoff + wp->sy;
 	int		 hsplit = 0, vsplit = 0, pane_status = ctx->pane_status;
 	int		 pane_scrollbars = ctx->pane_scrollbars, sb_w = 0;
-	int		 sb_pos = ctx->pane_scrollbars_pos;
+	int		 sb_pos;
+
+	if (pane_scrollbars != 0)
+		sb_pos = ctx->pane_scrollbars_pos;
+	else
+		sb_pos = 0;
 
 	/* Inside pane. */
 	if (px >= wp->xoff && px < ex && py >= wp->yoff && py < ey)
@@ -149,16 +154,24 @@ screen_redraw_pane_border(struct screen_redraw_ctx *ctx, struct window_pane *wp,
 			if (wp->xoff - sb_w == 0 && px == wp->sx + sb_w)
 				if (!hsplit || (hsplit && py <= wp->sy / 2))
 					return (SCREEN_REDRAW_BORDER_RIGHT);
-			if (wp->xoff - sb_w != 0 && px == wp->xoff - sb_w - 1)
-				if (!hsplit || (hsplit && py > wp->sy / 2))
+			if (wp->xoff - sb_w != 0) {
+				if (px == wp->xoff - sb_w - 1 &&
+				    (!hsplit || (hsplit && py > wp->sy / 2)))
 					return (SCREEN_REDRAW_BORDER_LEFT);
-		} else { /* sb_pos == PANE_SCROLLBARS_RIGHT */
+				if (px == wp->xoff + wp->sx + sb_w - 1)
+					return (SCREEN_REDRAW_BORDER_RIGHT);
+			}
+		} else { /* sb_pos == PANE_SCROLLBARS_RIGHT or disabled*/
 			if (wp->xoff == 0 && px == wp->sx + sb_w)
 				if (!hsplit || (hsplit && py <= wp->sy / 2))
 					return (SCREEN_REDRAW_BORDER_RIGHT);
-			if (wp->xoff != 0 && px == wp->xoff - 1)
-				if (!hsplit || (hsplit && py > wp->sy / 2))
+			if (wp->xoff != 0) {
+				if (px == wp->xoff - 1 &&
+				    (!hsplit || (hsplit && py > wp->sy / 2)))
 					return (SCREEN_REDRAW_BORDER_LEFT);
+				if (px == wp->xoff + wp->sx + sb_w)
+					return (SCREEN_REDRAW_BORDER_RIGHT);
+			}
 		}
 	}