From 3a6d6d740110e6ee1b092d05ad746244eedabe4b Mon Sep 17 00:00:00 2001
From: Shi Tian <shitian@cock.li>
Date: Sun, 25 Jun 2023 05:38:33 +0000
Subject: [PATCH] Fix for wide character being incorrectly cleared on
 MODE_INSERT
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Under insert mode, when inserting a normal character in front of
a wide character, the affected region is shifted to the right by
one cell. However, the empty cell is reset as if being a part of a
wide character, causing the following cell being mishandled as a
dummy cell.
To reproduce the bug:
	printf '\033[4h' # set MODE_INSERT
	printf 妳好
	printf '\033[4D'
	printf 'x'
	printf '\033[4l\n'
---
 st.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/st.c b/st.c
index 134e724..623376e 100644
--- a/st.c
+++ b/st.c
@@ -2471,8 +2471,10 @@ check_control_code:
 		gp = &term.line[term.c.y][term.c.x];
 	}
 
-	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col)
+	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col) {
 		memmove(gp+width, gp, (term.col - term.c.x - width) * sizeof(Glyph));
+		gp->mode &= ~ATTR_WIDE;
+	}
 
 	if (term.c.x+width > term.col) {
 		tnewline(1);