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Committer:
Dmitry V. Levin
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Author(s):
Nick Bowler
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Date:
2021-08-14 16:20:38 UTC
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Revision ID:
git-v1:191bcb948f7191c36eefe634336f5fc5c0c4c2be
config.sub: work around command assignment bug in some shells
When combining variable assignments with a shell command, some older
shells (notably heirloom-sh and presumably also Solaris 10 /bin/sh)
have a bug which causes the assignment to alter the current execution
environment whenever the command is a shell built-in. For example:
% dash -c 'x=good; x=bad echo >/dev/null; echo $x'
good
% jsh -c 'x=good; x=bad echo >/dev/null; echo $x'
bad
The config.sub script contains a few commands of the form:
IFS=- read ...
which triggers this bug, causing the IFS assignment to persist for the
remainder of the script. This can cause misbehaviour in certain cases,
for example:
% jsh config.sub i386-linux-gnu
config.sub: test: unknown operator gnu
% jsh config.sub i386-gnu/linux
sed: can't read s|gnu/linux|gnu|: No such file or directory
Invalid configuration `i386-gnu/linux': OS `' not recognized
* config.sub: Save and restore IFS explicitly to avoid shell bugs.
* doc/config.sub.1: Regenerate.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>