[pacman-dev] [PATCH 1/3] makepkg: use bash 4.4 to localize `set` without explicitly saving/restoring

[Eli Schwartz]

On 8/29/18 12:54 AM, Allan McRae wrote:
> On 14/08/18 11:20, Eli Schwartz wrote:
>> Signed-off-by: Eli Schwartz <eschwartz at archlinux.org>
>> ---
>>  scripts/makepkg.sh.in | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/scripts/makepkg.sh.in b/scripts/makepkg.sh.in
>> index 4024f477..bb8332c6 100644
>> --- a/scripts/makepkg.sh.in
>> +++ b/scripts/makepkg.sh.in
>> @@ -418,13 +418,14 @@ prepare_buildenv() {
>>  }
>>  
>>  run_function_safe() {
>> -	local restoretrap restoreset restoreshopt
>> +	local restoretrap restoreshopt
>>  
>>  	# we don't set any special shopts of our own, but we don't want the user to
>>  	# muck with our environment.
>>  	restoreshopt=$(shopt -p)
>>  
>> -	restoreset=$(shopt -o -p)
>> +	# localize sets, sadly this does not work for shopt
>> +	local -
> 
> My understanding is this does not quite do the same thing...   "local -"
> only save the single-letter shell options.  There are set options that
> do not have a single letter variants (although they are unlikely to be
> used...).

The manpage does not indicate this; it just says:

the set of shell options is made local to the function in which local is
invoked: shell options changed using the set builtin inside the function
are restored to their original values when the function returns.

So...

$ testfunc() { shopt -p -o pipefail; local -; set -o pipefail; shopt -p
-o pipefail; }
$ testfunc; shopt -p -o pipefail
set +o pipefail
set -o pipefail
set +o pipefail

Seems to work okay, fortunately.

-- 
Eli Schwartz
Bug Wrangler and Trusted User

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