Bug#385720: m4: INTERNAL ERROR: recursive push_string (fwd)

[Santiago Vila]

Hello.

I received this report from the Debian bug system:

Andreas Schultz <address@hidden> writes:

  m4 crashes with "m4: INTERNAL ERROR: recursive push_string"

Later, he adds:

  It seems that the problem is reproducible with every automake project
  that has a) AC_OUTPUT on the last line in configure.ac and b) no
  terminating newline on that line. Adding a newline will make the
  problem disappear.

and in fact, I can reproduce it using GNU hello 2.1.1 by removing the
last two lines of configure.ac, removing also the newline from the
AC_OUTPUT final line, and then trying "./configure; make configure".

This is with m4 1.4.6, and it did not happen with m4 1.4.4.

Thanks.