Re: Fix an 8-year-old AC_REQUIRE bug

[Paolo Bonzini]

Eric Blake wrote:
> Eric Blake <ebb9 <at> byu.net> writes:
> 
>> Here's my first draft of a patch.  Unfortunately, there is probably existing 
>> code that was expecting the old buggy behavior.
> 
> And here's my proposed patch that fixes those, by introducing a new macro 
> that 
> states when we want the old behavior (AS_IF, AS_CACHE_VAL, and maybe a small 
> handful of other places) instead of the new.  As a bonus, wrapping text in 
> AC_REQUIRE_HOIST issues a warning on code that was previously triggering the 
> buggy AC_REQUIRE behaivior.

IMHO, this can wait for 2.65... we changed enough m4sugar internals in
2.64, and all of them were in a backwards-compatible way.  If we stick
to that policy, understanding regressions will be much easier.

Paolo