> > > * lib/autotest/general.m4 (_AT_CHECK): Avoid syntax error on empty > > > check. > > > > That looks fine; please install. Thanks. > > Erm, instead of the > :; $1 > > could we just have > m4_default([$1], [:]) > > please? This avoids the size overhead incurred for the non-pathological > case.
Except that with your idea, with AT_CHECK([ ]) (note the space), the m4_default sees it as non-empty but shell syntax disagrees. I went the course of minimally invasive patch, by always ensuring valid syntax (assuming, of course, that the shell snippet handed to AT_CHECK is also valid outside of a subshell), rather than trying to play m4 games to guess when syntax is valid. Of course, how we handle something like AT_CHECK([;]) is up in the air, since by itself, ";" is not valid as a script outside of a subshell, nor would it be valid with either of our proposals. -- Eric Blake