For Debian Bug #206299:

For Debian Bug #206299:
* automake.in ($configure_deps_greatest_timestamp,
$output_deps_greatest_timestamp): New variables.
(initialize_per_input): Reset $output_deps_greatest_timestamp.
(scan_autoconf_traces, scan_autoconf_files, read_am_file):
Update $configure_deps_greatest_timestamp and
$output_deps_greatest_timestamp
(generate_makefile): Rewrite the logic to decide whether
to rewrite the output.  Move the leading dup_channel_setup
and trailing drop_channel_setup to MAIN, so that
drop_channel_setup is executed for all exit paths.
* tests/aclocal7.test: Update to check for $AUTOMAKE --no-force
* tests/distcom6.test: New file.  Report from Scott James Remnant.
* tests/Makefile.am (TESTS): Add distcom6.test.