Eric Blake <ebb9 <at> byu.net> writes: > > -m4_ifvaln([$1], [rm -f conftest.$ac_ext])dnl > > +rm -f conftest.err[]m4_ifvaln([$1], [ conftest.$ac_ext])dnl > > ])# _AC_PREPROC_IFELSE > > m4_ifvaln is primarily useful in situations where you want to avoid an empty > newline when $1 is empty. But here, you want to conditionally add content to a > line that needs a newline terminator no matter what. I'm worried that people > might be using dnl after AC_PREPROC_IFELSE to delete a second newline; which > means we would be causing a shell syntax error if we don't supply a first > newline.
On closer inspection, the original code before patches 1-4 had the dnl there (in other words, _AC_*_IFELSE did not end in a newline, because all clients always supplied it, so we were actually adding a blank newline by swapping over to m4_ifvaln). So I would restore the []dnl from the original code, and write this as: rm -f conftest.err[]m4_ifval([$1], [ conftest.$ac_ext])[]dnl ])# _AC_PREPROC_IFELSE -- Eric Blake
