tree 3e6fb84aa490cc05b6918c9c635df4d4f4198f95
parent f02691939eba5c043a90c0f1f428d4124dc83a1c
author Ron Yorston <rmy@pobox.com> 1630351902 +0100
committer Denys Vlasenko <vda.linux@googlemail.com> 1630597740 +0200

ash: regressions in process substitution

Stacy Harper reports that this script:

   test() { . /tmp/bb_test; }
   echo "export TEST=foo" >/tmp/bb_test
   test 2>/dev/null
   echo "$TEST"

correctly prints 'foo' in BusyBox 1.33 but hangs in 1.34.

Bisection suggested the problem was caused by commit a1b0d3856 (ash: add
process substitution in bash-compatibility mode).  Removing the call to
unwindredir() in cmdloop() introduced in that commit makes the script
work again.

Additionally, these examples of process substitution:

   while true; do cat <(echo hi); done
   f() { while true; do cat <(echo hi); done }
   f

result in running out of file descriptors.  This is a regression from
v5 of the process substitution patch caused by changes to evalcommand()
not being transferred to v6.

function                                             old     new   delta
static.pushredir                                       -      99     +99
evalcommand                                         1729    1750     +21
exitreset                                             69      86     +17
cmdloop                                              372     365      -7
unwindredir                                           28       -     -28
pushredir                                            112       -    -112
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 2/1 up/down: 137/-147)          Total: -10 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>