diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | Src/exec.c | 40 | ||||
| -rw-r--r-- | Src/jobs.c | 9 | ||||
| -rw-r--r-- | Test/E01options.ztst | 12 |
4 files changed, 62 insertions, 5 deletions
diff --git a/ChangeLog b/ChangeLog index 5d521e898..71f51a966 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2007-05-23 Peter Stephenson <pws@csr.com> + + * 23460: Src/exec.c, Src/jobs.c, Test/E01options.ztst: + fix longstanding problem with multios attached to a + subshell process. + 2007-05-22 Peter Stephenson <pws@csr.com> * Phil Pennock: 23450: Src/Zle/zleparameter.yo: undefined diff --git a/Src/exec.c b/Src/exec.c index a462a4ee9..5aa3dba12 100644 --- a/Src/exec.c +++ b/Src/exec.c @@ -1098,10 +1098,10 @@ execpline(Estate state, wordcode slcode, int how, int last1) child_block(); /* - * Get free entry in job table and initialize it. - * This is currently the only call to initjob(), so this - * is also the only place where we can expand the job table - * under us. + * Get free entry in job table and initialize it. This is currently + * the only call to initjob() (apart from a minor exception in + * clearjobtab()), so this is also the only place where we can + * expand the job table under us. */ if ((thisjob = newjob = initjob()) == -1) { child_unblock(); @@ -2816,8 +2816,38 @@ execcmd(Estate state, int input, int output, int how, int last1) } err: - if (forked) + if (forked) { + /* + * So what's going on here then? Well, I'm glad you asked. + * + * If we create multios for use in a subshell we do + * this after forking, in this function above. That + * means that the current (sub)process is responsible + * for clearing them up. However, the processes won't + * go away until we have closed the fd's talking to them. + * Since we're about to exit the shell there's nothing + * to stop us closing all fd's (including the ones 0 to 9 + * that we usually leave alone). + * + * Then we wait for any processes. When we forked, + * we cleared the jobtable and started a new job just for + * any oddments like this, so if there aren't any we won't + * need to wait. The result of not waiting is that + * the multios haven't flushed the fd's properly, leading + * to obscure missing data. + * + * It would probably be cleaner to ensure that the + * parent shell handled multios, but that requires + * some architectural changes which are likely to be + * hairy. + */ + for (i = 0; i < 10; i++) + if (fdtable[i] != FDT_UNUSED) + close(i); + closem(FDT_UNUSED); + waitjobs(); _exit(lastval); + } fixfds(save); done: diff --git a/Src/jobs.c b/Src/jobs.c index 53e654c2b..b02922a03 100644 --- a/Src/jobs.c +++ b/Src/jobs.c @@ -1296,6 +1296,15 @@ clearjobtab(int monitor) memset(jobtab, 0, jobtabsize * sizeof(struct job)); /* zero out table */ maxjob = 0; + + /* + * Although we don't have job control in subshells, we + * sometimes needs control structures for other purposes such + * as multios. Grab a job for this purpose; any will do + * since we've freed them all up (so there's no question + * of problems with the job table size here). + */ + thisjob = initjob(); } static int initnewjob(int i) diff --git a/Test/E01options.ztst b/Test/E01options.ztst index 1fbe0cc93..0ce82b3ab 100644 --- a/Test/E01options.ztst +++ b/Test/E01options.ztst @@ -655,6 +655,18 @@ >This is in1 >This is in2 +# This is trickier than it looks. There's a hack at the end of +# execcmd() to catch the multio processes attached to the +# subshell, which otherwise sort of get lost in the general turmoil. +# Without that, the multios aren't synchronous with the subshell +# or the main shell starting the "cat", so the output files appear +# empty. + setopt multios + ( echo hello ) >multio_out1 >multio_out2 && cat multio_out* +0:Multios attached to a subshell +>hello +>hello + # tried this with other things, but not on its own, so much. unsetopt nomatch print with nonomatch: flooble* |