Hi. Is there a way to prevent this segmentation fault in Bash? I'm not sure
where the fault happens but when there's a function that handles a trap and
when a signal is caught during a session of read with -t, Bash crashes. An
example code that makes this happen is this:
--------------------
#!/bin/bash
shopt -s -o monitor
function catch {
echo catch.
}
trap catch SIGCHLD
while :; do
echo summon.
sleep 4s &
echo :
:
echo disown.
disown
echo read.
read -t 1
done
--------------------
The output would be something like this:
--------------------
...
summon.
:
disown.
read.
catch.
summon.
:
disown.
read.
catch.
*** glibc detected *** bash: double free or corruption (fasttop):
0x0000000000f18210 ***
Segmentation fault
--------------------
Sometimes there's also a message like:
--------------------
Inconsistency detected by ld.so: dl-open.c: 221: dl_open_worker: Assertion
`_dl_debug_initialize (0, args->nsid)->r_state == RT_CONSISTENT' failed!
--------------------
It doesn't seem to crash though if the execution of the child process was
started outside just like in this script:
--------------------
#!/bin/bash
shopt -s -o monitor
function summon {
echo summon.
sleep 4s &
disown
}
trap summon SIGCHLD
summon
while :; do
echo read.
read -t 1
done
--------------------
Is there a way to prevent that from happening? I've been having this
problem already since 2008. It happened in systems like Gentoo and
Slackware in all versions of Bash that I had used (at least starting 3.0).
And the current version of Bash that I'm using is 4.2.37.
It also rarely happens if I increase the length of timeout in read but it
still does happen sometimes.
