Re: AC_TRY_COMPILE() annoyances with 2.63b

[Eric Blake]

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According to Mike Frysinger on 4/14/2009 4:27 PM:
>> $ if false; then :; else echo $?; fi
>> 1
>>
>> But adding the : after the else, we have effectively made it impossible
>> for the user to grab $? after the if condition, so I'll have to rethink
>> this patch.
> 
> use "(exit $?);" instead ?

Absolutely not - that would be a performance killer (bash is among the
shells that don't optimize away the subshell fork).

To put it in perspective, before this week, all four of these would cause
a syntax error:

AS_IF([:], [AC_REQUIRE(...)])
AS_IF([false], [], [AC_REQUIRE(...)])
AS_IF([:], [ ])
AS_IF([:], [], [ ])

whereas even with today's regression fix, three of the four now pass
(we're more lenient than we used to be, and we aren't breaking any
existing scripts that used proper quoting).

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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