commit 8c68ec52419f3f965164cafcf589b87e8961348d
from: Hiltjo Posthuma <hiltjo@codemadness.org>
date: Sat Mar 30 11:37:06 2024 UTC

Revert "Fix cursor move with wide glyphs"

This reverts commit 7473a8d1a57e5f9aba41b953f4e498c35e1c9dc5.

This patch needs some more work. It caused regressions with programs that use
GNU readline, etc.

Original test-case example from Tim Culverhouse <tim@timculverhouse.com>:

	printf " 😀" && sleep 2 && printf "\e[D" && sleep 2 && printf "\e[D" && sleep 2

After the patch it caused regressions, example test-case:

	printf "A字\bB\n"

commit - 5ce971628106fb767ef91bf4386227423f5fdf98
commit + 8c68ec52419f3f965164cafcf589b87e8961348d
blob - 683493d3aa66fc346eb0eadc1c6e8f8bdd08dac8
blob + b9f66e71163f0707bb477f9fa5346f5dad27683d
--- st.c
+++ st.c
@@ -86,8 +86,8 @@ enum escape_state {
 
 typedef struct {
 	Glyph attr; /* current char attributes */
-	int x; /* terminal column */
-	int y; /* terminal row */
+	int x;
+	int y;
 	char state;
 } TCursor;
 
@@ -2175,16 +2175,12 @@ tstrsequence(uchar c)
 void
 tcontrolcode(uchar ascii)
 {
-	size_t i;
-
 	switch (ascii) {
 	case '\t':   /* HT */
 		tputtab(1);
 		return;
 	case '\b':   /* BS */
-		for (i = 1; term.c.x && term.line[term.c.y][term.c.x - i].u == 0; ++i)
-			;
-		tmoveto(term.c.x - i, term.c.y);
+		tmoveto(term.c.x-1, term.c.y);
 		return;
 	case '\r':   /* CR */
 		tmoveto(0, term.c.y);