Re: bug-report: debug trap messes up pipestatus if containing command substitution

[Chet Ramey]

On 5/23/19 5:11 PM, Hengyang Zhao wrote:
> Awesome! Could you please cc the fix to this thread once it's done? Thank you!
It's in the devel branch. I've attached the relevant piece.

This is more confirmation that it was a mistake to apply the DEBUG trap to
simple commands in pipelines.


-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    c...@case.edu    http://tiswww.cwru.edu/~chet/

*** ../bash-20190517/jobs.c     2019-04-12 15:15:10.000000000 -0400
--- jobs.c      2019-05-25 18:03:47.000000000 -0400
***************
*** 244,247 ****
--- 244,248 ----
  static int waitchld __P((pid_t, int));
  
+ static PROCESS *find_pid_in_pipeline __P((pid_t, PROCESS *, int));
  static PROCESS *find_pipeline __P((pid_t, int, int *));
  static PROCESS *find_process __P((pid_t, int, int *));
***************
*** 1493,1496 ****
--- 1494,1518 ----
  }
  
+ static PROCESS *
+ find_pid_in_pipeline (pid, pipeline, alive_only)
+      pid_t pid;
+      PROCESS *pipeline;
+      int alive_only;
+ {
+   PROCESS *p;
+ 
+   p = pipeline;
+   do
+     {
+       /* Return it if we found it.  Don't ever return a recycled pid. */
+       if (p->pid == pid && ((alive_only == 0 && PRECYCLED(p) == 0) || 
PALIVE(p)))
+       return (p);
+ 
+       p = p->next;
+     }
+   while (p != pipeline);
+   return ((PROCESS *)NULL);
+ }
+ 
  /* Return the pipeline that PID belongs to.  Note that the pipeline
     doesn't have to belong to a job.  Must be called with SIGCHLD blocked.
***************
*** 1504,1538 ****
    int job;
    PROCESS *p;
  
    /* See if this process is in the pipeline that we are building. */
    if (jobp)
      *jobp = NO_JOB;
!   if (the_pipeline)
!     {
!       p = the_pipeline;
!       do
!       {
!         /* Return it if we found it.  Don't ever return a recycled pid. */
!         if (p->pid == pid && ((alive_only == 0 && PRECYCLED(p) == 0) || 
PALIVE(p)))
!           return (p);
  
!         p = p->next;
!       }
!       while (p != the_pipeline);
!     }
    /* Now look in the last process substitution pipeline, since that sets $! */
!   if (last_procsub_child)
!     {
!       p = last_procsub_child;
!       do
!       {
!         /* Return it if we found it.  Don't ever return a recycled pid. */
!         if (p->pid == pid && ((alive_only == 0 && PRECYCLED(p) == 0) || 
PALIVE(p)))
!           return (p);
! 
!         p = p->next;
!       }
!       while (p != last_procsub_child);
!     }
  
    job = find_job (pid, alive_only, &p);
--- 1526,1546 ----
    int job;
    PROCESS *p;
+   struct pipeline_saver *save;
  
    /* See if this process is in the pipeline that we are building. */
+   p = (PROCESS *)NULL;
    if (jobp)
      *jobp = NO_JOB;
!   if (the_pipeline && (p = find_pid_in_pipeline (pid, the_pipeline, 
alive_only)))
!     return (p);
  
!   /* Is this process in a saved pipeline? */
!   for (save = saved_pipeline; save; save = save->next)
!     if (save->pipeline && (p = find_pid_in_pipeline (pid, save->pipeline, 
alive_only)))
!       return (p);
!   
    /* Now look in the last process substitution pipeline, since that sets $! */
!   if (last_procsub_child && (p = find_pid_in_pipeline (pid, 
last_procsub_child, alive_only)))
!     return (p);
  
    job = find_job (pid, alive_only, &p);