From ebd1614316ea541cd1ac0cc0029f771be333176e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Fri, 16 May 2025 10:46:25 +0200
Subject: [PATCH] csi: when REP:ing a "combining" character, use correct width

Before this patch, we just called c32width(), which only works on
actual codepoints. If the last printed character is a "combining"
character, i.e. a key into our lookup table for multi-codepoint
graphemes, we need to lookup the grapheme and pick the width from
there.

See https://gitlab.com/AutumnMeowMeow/jexer/-/issues/119#note_2499712901
---
 CHANGELOG.md |  4 ++++
 csi.c        | 12 +++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ea818d53..00c1f0a0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -116,6 +116,10 @@
 
 ### Removed
 ### Fixed
+
+* `REP`: wrong width of repeated multi-codepoint graphemes.
+
+
 ### Security
 ### Contributors
 
diff --git a/csi.c b/csi.c
index e8b2c492..6d4845be 100644
--- a/csi.c
+++ b/csi.c
@@ -799,7 +799,17 @@ csi_dispatch(struct terminal *term, uint8_t final)
                 int count = vt_param_get(term, 0, 1);
                 LOG_DBG("REP: '%lc' %d times", (wint_t)term->vt.last_printed, count);
 
-                const int width = c32width(term->vt.last_printed);
+                int width;
+
+                if (term->vt.last_printed >= CELL_COMB_CHARS_LO) {
+                    const struct composed *comp = composed_lookup(
+                        term->composed, term->vt.last_printed - CELL_COMB_CHARS_LO);
+
+                    xassert(comp != NULL);
+                    width = comp->forced_width > 0 ? comp->forced_width : comp->width;
+                } else
+                    width = c32width(term->vt.last_printed);
+
                 if (width > 0) {
                     for (int i = 0; i < count; i++)
                         term_print(term, term->vt.last_printed, width, false);