[src/trunk]: src/lib/libc/gen Fix handling of memory allocation. From OpenBSD.

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ea7fe613a3cd
branches:  trunk
changeset: 572500:ea7fe613a3cd
user:      christos <christos%NetBSD.org@localhost>
date:      Thu Jan 06 00:07:41 2005 +0000

description:
Fix handling of memory allocation. From OpenBSD.

diffstat:

 lib/libc/gen/getcwd.c |  19 ++++++++++---------
 1 files changed, 10 insertions(+), 9 deletions(-)

diffs (59 lines):

diff -r 28bb8e57d6b8 -r ea7fe613a3cd lib/libc/gen/getcwd.c
--- a/lib/libc/gen/getcwd.c     Wed Jan 05 23:39:51 2005 +0000
+++ b/lib/libc/gen/getcwd.c     Thu Jan 06 00:07:41 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: getcwd.c,v 1.32 2003/08/07 16:42:49 agc Exp $  */
+/*     $NetBSD: getcwd.c,v 1.33 2005/01/06 00:07:41 christos Exp $     */
 
 /*
  * Copyright (c) 1989, 1991, 1993, 1995
@@ -37,7 +37,7 @@
 #if 0
 static char sccsid[] = "@(#)getcwd.c   8.5 (Berkeley) 2/7/95";
 #else
-__RCSID("$NetBSD: getcwd.c,v 1.32 2003/08/07 16:42:49 agc Exp $");
+__RCSID("$NetBSD: getcwd.c,v 1.33 2005/01/06 00:07:41 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -222,7 +222,7 @@
        ino_t root_ino;
        size_t ptsize, upsize;
        int save_errno;
-       char *ept, *eup, *up;
+       char *ept, *eup, *up, *nup;
        size_t dlen;
 
        /*
@@ -246,13 +246,13 @@
        *bpt = '\0';
 
        /*
-        * Allocate bytes (1024 - malloc space) for the string of "../"'s.
+        * Allocate bytes for the string of "../"'s.
         * Should always be enough (it's 340 levels).  If it's not, allocate
         * as necessary.  Special case the first stat, it's ".", not "..".
         */
-       if ((up = malloc(upsize = 1024 - 4)) == NULL)
+       if ((up = malloc(upsize = MAXPATHLEN)) == NULL)
                goto err;
-       eup = up + MAXPATHLEN;
+       eup = up + upsize;
        bup = up;
        up[0] = '.';
        up[1] = '\0';
@@ -292,10 +292,11 @@
                 * as necessary.  Max length is 3 for "../", the largest
                 * possible component name, plus a trailing NULL.
                 */
-               if (bup + 3  + MAXNAMLEN + 1 >= eup) {
-                       if ((up = realloc(up, upsize *= 2)) == NULL)
+               if (bup + 3 + MAXNAMLEN + 1 >= eup) {
+                       if ((nup = realloc(up, upsize *= 2)) == NULL)
                                goto err;
-                       bup = up;
+                       bup = nup + (buf - up);
+                       up = nup;
                        eup = up + upsize;
                }
                *bup++ = '.';