Hi Folks,
The mg command 'regexp-replace "^.*$" ""' enters an endless loop (until
memory exhausted). This behaviour also occurs in query-replace-regexp
with the "!" option.
This is due to a change I suggested to re_forwsrch, that is, not moving
dot when the line is empty (re_search.c 1.35). The reason for this
change was to ensure the replacement took effect on the starting line of
a replace-regexp, even if the line was empty. Well, the patch did that but
caused this worse issue instead. <Hangs head in shame>.
Here's yet another suggested patch (3 of 3) to fix the issue:
--- re_search.c.orig Fri Apr 12 09:32:15 2024
+++ re_search.c Fri Apr 12 14:00:54 2024
@@ -146,6 +146,11 @@
return (ABORT);
ewprintf("Query replacing %s with %s:", re_pat, news);
+ /* If dot on empty line, instruct re_forwsrch to not advance
+ * line
+ */
+ if (curwp->w_doto == 0 && curwp->w_dotp->l_used == 0)
+ curwp->w_doto = -1;
/*
* Search forward repeatedly, checking each time whether to insert
* or not. The "!" case makes the check always true, so it gets put
@@ -220,6 +225,8 @@
EFNUL | EFNEW | EFCR, re_pat) == NULL)
return (ABORT);
+ if (curwp->w_doto == 0 && curwp->w_dotp->l_used == 0)
+ curwp->w_doto = -1;
while (re_forwsrch() == TRUE) {
plen = regex_match[0].rm_eo - regex_match[0].rm_so;
if (re_doreplace((RSIZE)plen, news) == FALSE)
@@ -231,7 +238,7 @@
update(CMODE);
if (!inmacro)
ewprintf("(%d replacement(s) done)", rcnt);
-
+
return(TRUE);
}
mg: endless loop using replace-regexpmg: endless loop using replace-regexp
@@ -339,17 +346,24 @@
tbo = curwp->w_doto;
tdotline = curwp->w_dotline;
- if (tbo == clp->l_used)
+ if (tbo == clp->l_used) {
/*
* Don't start matching past end of line -- must move to
- * beginning of next line, unless line is empty or at
- * end of file.
+ * beginning of next line, unless at end of file.
*/
- if (clp != curbp->b_headp && llength(clp) != 0) {
+ if (clp != curbp->b_headp) {
clp = lforw(clp);
tdotline++;
tbo = 0;
}
+ }
+ else if (tbo < 0) {
+ /* Don't advance to next line when dot on empty line;
+ * reset tbo to correct value.
+ */
+ tbo = 0;
+ }
+
/*
* Note this loop does not process the last line, but this editor
* always makes the last line empty so this is good.
Best Regards.
Mark
