From 0b2786562554decb15ee1578344842255ca4168d Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 3 Jul 2026 04:05:40 +0000
Subject: [PATCH] Address review comments: clarify reversed reset and vertical
 NULL params

---
 kitty/screen.c | 2 +-
 kitty/state.c  | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/kitty/screen.c b/kitty/screen.c
index e9ac71fdd..e340a2a4a 100644
--- a/kitty/screen.c
+++ b/kitty/screen.c
@@ -3453,7 +3453,7 @@ get_line_edge_colors_at_row(Screen *self, index_type y, color_type *left, color_
     if (left) *left = effective_cell_edge_color(left_char, left_cell_fg, left_cell_bg, true);
     if (line->xnum > 0) cell_color_x = line->xnum - 1;
     char_type right_char = line_get_char(line, cell_color_x);
-    reversed = false;
+    reversed = false;  // reset: colors_for_cell only sets this flag, never clears it
     colors_for_cell(line, self->color_profile, &cell_color_x, &right_cell_fg, &right_cell_bg, &reversed);
     if (right_is_default) *right_is_default = (line->gpu_cells[cell_color_x].bg & 0xff) == 0;
     if (right) *right = effective_cell_edge_color(right_char, right_cell_fg, right_cell_bg, false);
diff --git a/kitty/state.c b/kitty/state.c
index fba0a0599..fd478baf9 100644
--- a/kitty/state.c
+++ b/kitty/state.c
@@ -1420,6 +1420,8 @@ PYWRAP1(update_tab_bar_edge_colors) {
             } else {
                 color_type top_color = 0, bottom_color = 0;
                 bool top_is_default = true, bottom_is_default = true;
+                // For vertical bars we only need the left-edge color of each row (the
+                // right-edge output is unused since tabs span the full row width).
                 ok = get_line_edge_colors_at_row(screen, 0, &top_color, NULL, &top_is_default, NULL) &&
                      get_line_edge_colors_at_row(screen, screen->lines - 1, &bottom_color, NULL, &bottom_is_default, NULL);
                 if (ok) {