mirror of
https://github.com/sheumann/hush.git
synced 2025-01-10 16:29:44 +00:00
7b3fa1e441
Upstream commit:
Date: Tue Aug 11 20:48:15 2009 +1000
[EVAL] Pass EV_TESTED into evalcmd
This patch fixes the case where the eval command is used with
set -e and as part of a construct that should not cause the
shell to abort, e.g., as part of the condition of an if statement.
This is achieved by propagating the EV_TESTED flag into the
evalstring function through evalcmd. As this alters the prototype
of evalcmd it is now invoked explicitly by evalbltin. The built-in
infrastructure has been changed to accomodate this special case.
In order to ensure that the EXIT trap is properly executed this
patch clears evalskip in exitshell. This wasn't needed before
because of the broken way evalstring worked where it always clears
evalskip when called by minusc.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Although, I failed to create a reproducer for this.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
http://www.opengroup.org/onlinepubs/9699919799/ Open Group Base Specifications Issue 7 http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap01.html Shell & Utilities It says that any of the standard utilities may be implemented as a regular shell built-in. It gives a list of utilities which are usually implemented that way (and some of them can only be implemented as built-ins, like "alias"): alias bg cd command false fc fg getopts jobs kill newgrp pwd read true umask unalias wait http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html Shell Command Language It says that shell must implement special built-ins. Special built-ins differ from regular ones by the fact that variable assignments done on special builtin are *PRESERVED*. That is, VAR=VAL special_builtin; echo $VAR should print VAL. (Another distinction is that an error in special built-in should abort the shell, but this is not such a critical difference, and moreover, at least bash's "set" does not follow this rule, which is even codified in autoconf configure logic now...) List of special builtins: . file : [argument...] break [n] continue [n] eval [argument...] exec [command [argument...]] exit [n] export name[=word]... export -p readonly name[=word]... readonly -p return [n] set [-abCefhmnuvx] [-o option] [argument...] set [+abCefhmnuvx] [+o option] [argument...] set -- [argument...] set -o set +o shift [n] times trap n [condition...] trap [action condition...] unset [-fv] name... In practice, no one uses this obscure feature - none of these builtins gives any special reasons to play such dirty tricks. However. This section also says that *function invocation* should act similar to special built-in. That is, variable assignments done on function invocation should be preserved after function invocation. This is significant: it is not unthinkable to want to run a function with some variables set to special values. But because of the above, it does not work: variable will "leak" out of the function.