Configuration Information [Automatically generated, do not change]:
Machine: i486
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='i486'
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i486-pc-linux-gnu'
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash'
-DSHELL -DHAVE_CONFIG_H -I. -I../bash -I../bash/include -I../bash/lib
-g -O2 -Wall
uname output: Linux cargocult 2.6.20-16-generic #2 SMP Sun Sep 23
19:50:39 UTC 2007 i686 GNU/Linux
Machine Type: i486-pc-linux-gnu
Bash Version: 3.2
Patch Level: 13
Release Status: release
Description:
Whether orr not ERR traps get invoked for failed simple commands
inside a function depends on whether or not the error status is
to be ignored for any function invocation in the call stack
leading to the current function. This makes it practically
impossible to reliably use ERR traps for error handling inside
functions. This affects the -e option as well.
The documentation isn't clear on what the behaviour should be --
is every command inside a function considered to be "part of"
all command lists that directly or indirectly invoke the
function? This would mean that a function cannot rely on a
failed simple command behaving in any particular way -- to write
a function that can handle this robustly, every command
would have to be suffixed with either || true or || return.
Unfortunately the situation is not as easy for -e: If a simple
command failure inside a function caused the entire shell to
terminate, any attempt by the caller to catch failures of that
function would be ignored. It seems the most desirable behaviour
would be to have a mode where a failed simple command causes the
current function to propagate the status of the failed command
to the caller.
Repeat-By:
bash -c 'set -E; trap "echo ERR" ERR; f() { false; }; g() { f; }
; g; echo -; g || true'
Output:
ERR
ERR
ERR
-
Expected
ERR
ERR
ERR
-
ERR
ERR
Fix:
Don't propagate CMD_IGNORE_RETURN into function invocations.
*** execute_cmd.c.orig 2007-11-12 15:10:54.000000000 +1300
--- execute_cmd.c 2007-11-12 15:55:52.000000000 +1300
***************
*** 3192,3199 ****
#endif
tc = (COMMAND *)copy_command (function_cell (var));
- if (tc && (flags & CMD_IGNORE_RETURN))
- tc->flags |= CMD_IGNORE_RETURN;
if (subshell == 0)
{
--- 3192,3197 ----
