vac: fix segfault on DMSYMLINK or DMDEVICE
Fix segfault when the first archived file is DMSYMLINK or DMDEVICE.
Reinitialize the buffer to zero before calling readlink.
R=rsc
CC=plan9port.codebot
http://codereview.appspot.com/5500097
diff --git a/src/cmd/vac/vac.c b/src/cmd/vac/vac.c
index 5f89631..03ada7b 100644
--- a/src/cmd/vac/vac.c
+++ b/src/cmd/vac/vac.c
@@ -501,12 +501,17 @@
if(vacfilesetdir(f, &vd) < 0)
warn("vacfilesetdir %s: %r", name);
-
+
+ bsize = fs->bsize;
+ if(buf == nil)
+ buf = vtmallocz(bsize);
+
#ifdef PLAN9PORT
if(d->mode&(DMSOCKET|DMNAMEDPIPE)){
/* don't write anything */
}
else if(d->mode&DMSYMLINK){
+ memset(buf, 0, sizeof buf);
n = readlink(name, buf, sizeof buf);
if(n > 0 && vacfilewrite(f, buf, n, 0) < 0){
warn("venti write %s: %r", name);
@@ -539,9 +544,6 @@
}
}else{
off = 0;
- bsize = fs->bsize;
- if(buf == nil)
- buf = vtmallocz(bsize);
if(fdiff){
/*
* Copy fdiff's contents into f by moving the score.
