[hackers] [st] Revert "Fix cursor move with wide glyphs" || Hiltjo Posthuma

[git]

commit 8c68ec52419f3f965164cafcf589b87e8961348d
Author:     Hiltjo Posthuma <hil...@codemadness.org>
AuthorDate: Sat Mar 30 12:30:49 2024 +0100
Commit:     Hiltjo Posthuma <hil...@codemadness.org>
CommitDate: Sat Mar 30 12:37:06 2024 +0100

    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 <t...@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"

diff --git a/st.c b/st.c
index 683493d..b9f66e7 100644
--- a/st.c
+++ b/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);