Fix the begin of word bug in s-command, similar to sed.

nit fix and OK schwarze@

diff --git a/bin/ed/sub.c b/bin/ed/sub.c
index 2da4e9d..05f6c98 100644 (file)
--- a/bin/ed/sub.c
+++ b/bin/ed/sub.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: sub.c,v 1.15 2016/03/22 17:58:28 mmcc Exp $   */
+/*     $OpenBSD: sub.c,v 1.16 2016/08/02 20:17:06 martijn Exp $        */
 /*     $NetBSD: sub.c,v 1.4 1995/03/21 09:04:50 cgd Exp $      */
 
 /* sub.c: This file contains the substitution routines for the ed
@@ -173,7 +173,8 @@ search_and_replace(regex_t *pat, int gflag, int kth)
 
 
 /* substitute_matching_text: replace text matched by a pattern according to
-   a substitution template; return pointer to the modified text */
+   a substitution template; return length of rbuf if changed, 0 if unchanged, or
+   ERR on error */
 static int
 substitute_matching_text(regex_t *pat, line_t *lp, int gflag, int kth)
 {
@@ -181,11 +182,12 @@ substitute_matching_text(regex_t *pat, line_t *lp, int gflag, int kth)
        int changed = 0;
        int matchno = 0;
        int i = 0;
+       int inf = 0;
        regmatch_t rm[SE_MAX];
        char *txt;
-       char *eot;
+       char *eot, *eom;
 
-       if ((txt = get_sbuf_line(lp)) == NULL)
+       if ((eom = txt = get_sbuf_line(lp)) == NULL)
                return ERR;
        if (isbinary)
                NUL_TO_NEWLINE(txt, lp->len);
@@ -193,36 +195,37 @@ substitute_matching_text(regex_t *pat, line_t *lp, int gflag, int kth)
        if (!regexec(pat, txt, SE_MAX, rm, 0)) {
                do {
                        if (!kth || kth == ++matchno) {
-                               changed++;
-                               i = rm[0].rm_so;
+                               changed = 1;
+                               i = rm[0].rm_so - (eom - txt);
                                REALLOC(rbuf, rbufsz, off + i, ERR);
                                if (isbinary)
-                                       NEWLINE_TO_NUL(txt, rm[0].rm_eo);
-                               memcpy(rbuf + off, txt, i);
+                                       NEWLINE_TO_NUL(eom,
+                                           rm[0].rm_eo - (eom - txt));
+                               memcpy(rbuf + off, eom, i);
                                off += i;
                                if ((off = apply_subst_template(txt, rm, off,
                                    pat->re_nsub)) < 0)
                                        return ERR;
-                       } else {
-                               i = rm[0].rm_eo;
-                               REALLOC(rbuf, rbufsz, off + i, ERR);
-                               if (isbinary)
-                                       NEWLINE_TO_NUL(txt, i);
-                               memcpy(rbuf + off, txt, i);
-                               off += i;
+                               eom = txt + rm[0].rm_eo;
+                               if (kth)
+                                       break;
                        }
-                       txt += rm[0].rm_eo;
-               } while (*txt && (!changed || ((gflag & GSG) && rm[0].rm_eo)) &&
-                   !regexec(pat, txt, SE_MAX, rm, REG_NOTBOL));
-               i = eot - txt;
+                       if (rm[0].rm_so == rm[0].rm_eo)
+                               inf = 1;
+                       rm[0].rm_so = rm[0].rm_eo;
+                       rm[0].rm_eo = lp->len;
+               } while (rm[0].rm_so < lp->len &&
+                   (!changed || ((gflag & GSG) && !inf)) &&
+                   !regexec(pat, txt, SE_MAX, rm, REG_STARTEND | REG_NOTBOL));
+               i = eot - eom;
                REALLOC(rbuf, rbufsz, off + i + 2, ERR);
-               if (i > 0 && !rm[0].rm_eo && (gflag & GSG)) {
+               if (i > 0 && (gflag & GSG) && inf) {
                        seterrmsg("infinite substitution loop");
                        return  ERR;
                }
                if (isbinary)
-                       NEWLINE_TO_NUL(txt, i);
-               memcpy(rbuf + off, txt, i);
+                       NEWLINE_TO_NUL(eom, i);
+               memcpy(rbuf + off, eom, i);
                memcpy(rbuf + off + i, "\n", 2);
        }
        return changed ? off + i + 1 : 0;