Hi,
we've found a regression in ksh. For following script (see below), ksh
2010-12-01 and older print two lines (one child, one parent), but
2010-12-12 and newer print three lines (one child, parent twice).
Reproducer:
===============cut here===========================
#!/bin/sh
cat >/tmp/test_parent <<EOF
#!/bin/ksh
/tmp/test_child >/tmp/abc |&
sleep 3600
print -p "hello world"
EOF
cat >/tmp/test_child <<EOF
#!/bin/ksh
read var
print $var
EOF
chmod +x /tmp/test_child /tmp/test_parent
/tmp/test_parent >/dev/null 2>&1 &
sleep 1
ps | sed -n -e '/sed /d' -e '/test_parent/p' -e '/test_child/p'
exec >/dev/null 2>&1
killall test_child
killall test_parent
rm -f /tmp/test_child /tmp/test_parent
===============cut here===========================
Old working versions print:
$ ./reproducer.sh
8263 pts/4 00:00:00 test_parent
8265 pts/4 00:00:00 test_child
new versions print:
$ ./reproducer.sh
15093 pts/4 00:00:00 test_parent
15095 pts/4 00:00:00 test_parent
15096 pts/4 00:00:00 test_child
This is caused by following change:
===============cut here===========================
--- old/include/defs.h Wed Nov 3 16:04:52 2010
+++ new/include/defs.h Sun Dec 5 12:18:54 2010
@@ -162,6 +162,7 @@
pid_t cpid; \
pid_t spid; /* subshell process id */ \
pid_t pipepid; \
+ pid_t outpipepid; \
int topfd; \
int savesig; \
unsigned char *sigflag; /* pointer to signal states */ \
--- old/sh/io.c Thu Dec 2 10:39:41 2010
+++ new/sh/io.c Sun Dec 5 19:32:44 2010
@@ -1399,7 +1399,7 @@
}
if(!np)
{
- if(flag==0 || tname)
+ if(flag==0 || tname || (flag==1 && fn==1 &&
(shp->fdstatus[fn]&IONOSEEK) && shp->outpipepid &&
shp->outpipepid==getpid()))
{
if(fd==fn)
{
--- old/sh/xec.c Thu Dec 2 15:56:45 2010
+++ new/sh/xec.c Sun Dec 5 19:33:28 2010
@@ -2928,6 +2928,7 @@
#if !_std_malloc
vmtrace(-1);
#endif
+ shp->outpipepid = ((flags&FPOU)?getpid():0);
/* This is the child process */
if(shp->trapnote&SH_SIGTERM)
sh_exit(SH_EXITSIG|SIGTERM);
===============cut here===========================
which is probably this change:
10-12-06 A bug in which a pipeline could terminate prematurely for a
pipeline whose right hand side is a builtin, and whose left hand side
ends in a simple command that has standard output redirected has been fixed.
Let me know if you need more information.
Michal
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