From a3016a6cc909d9c383359a4eaafd30bcd52bd272 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Tue, 30 Nov 2021 19:36:28 +0100
Subject: [PATCH] =?UTF-8?q?osc-4:=20don=E2=80=99t=20update=20the=20color?=
 =?UTF-8?q?=20of=20cells=20with=20RGB=20fg/bg=20colors?=
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OSC 4/104 changes the 256-color palette. We also run a pass over the
visible cells, and update their colors.

This was previously done by comparing the actual color of the cell,
with the “old” color in the palette. If they matched, the cell was
updated.

This meant that cells with an RGB color (i.e. not a palette based
color) was also updated, _if_ its color matched the palette color.

Now that each cell tracks its color *source*, we can ignore all
non-palette based cells.

Note that this still isn’t perfect: if the palette contains multiple
entries with the same color, we’ll end up updating the “wrong” cells.

Closes #678
---
 CHANGELOG.md |  2 ++
 osc.c        | 22 +++++++++++-----------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1a725822..026e745c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -62,6 +62,8 @@
 * Visual corruption with large CSD borders
   (https://codeberg.org/dnkl/foot/issues/823).
 * Mouse cursor shape sometimes not being updated correctly.
+* Color palette changes (via OSC 4/104) no longer affect RGB colors
+  (https://codeberg.org/dnkl/foot/issues/678).
 
 
 ### Security
diff --git a/osc.c b/osc.c
index 910c1e02..357139b6 100644
--- a/osc.c
+++ b/osc.c
@@ -528,8 +528,7 @@ osc_notify(struct terminal *term, char *string)
 }
 
 static void
-update_color_in_grids(struct terminal *term, uint32_t old_color,
-                      uint32_t new_color)
+update_color_in_grids(struct terminal *term, int palette_idx, uint32_t new_color)
 {
     /*
      * Update color of already rendered cells.
@@ -560,16 +559,19 @@ update_color_in_grids(struct terminal *term, uint32_t old_color,
 
             for (size_t c = 0; c < term->grid->num_cols; c++) {
                 struct cell *cell = &row->cells[c];
-                if (cell->attrs.fg_src != COLOR_DEFAULT &&
-                    cell->attrs.fg == old_color)
+                enum color_source fg_src = cell->attrs.fg_src;
+                enum color_source bg_src = cell->attrs.bg_src;
+
+                if ((fg_src == COLOR_BASE16 || fg_src == COLOR_BASE256) &&
+                    cell->attrs.fg == term->colors.table[palette_idx])
                 {
                     cell->attrs.fg = new_color;
                     cell->attrs.clean = 0;
                     row->dirty = true;
                 }
 
-                if (cell->attrs.bg_src != COLOR_DEFAULT &&
-                    cell->attrs.bg == old_color)
+                if ((bg_src == COLOR_BASE16 || bg_src == COLOR_BASE256) &&
+                    cell->attrs.bg == term->colors.table[palette_idx])
                 {
                     cell->attrs.bg = new_color;
                     cell->attrs.clean = 0;
@@ -666,7 +668,7 @@ osc_dispatch(struct terminal *term)
                 LOG_DBG("change color definition for #%u from %06x to %06x",
                         idx, term->colors.table[idx], color);
 
-                update_color_in_grids(term, term->colors.table[idx], color);
+                update_color_in_grids(term, idx, color);
                 term->colors.table[idx] = color;
             }
         }
@@ -810,8 +812,7 @@ osc_dispatch(struct terminal *term)
         if (strlen(string) == 0) {
             LOG_DBG("resetting all colors");
             for (size_t i = 0; i < ALEN(term->colors.table); i++) {
-                update_color_in_grids(
-                    term, term->colors.table[i], term->conf->colors.table[i]);
+                update_color_in_grids(term, i, term->conf->colors.table[i]);
                 term->colors.table[i] = term->conf->colors.table[i];
         }
         }
@@ -834,8 +835,7 @@ osc_dispatch(struct terminal *term)
                 }
 
                 LOG_DBG("resetting color #%u", idx);
-                update_color_in_grids(
-                    term, term->colors.table[idx], term->conf->colors.table[idx]);
+                update_color_in_grids(term, idx, term->conf->colors.table[idx]);
                 term->colors.table[idx] = term->conf->colors.table[idx];
             }
         }