amend: allow aborting an `amend --patch` by saving an empty file (issue5925)
This patch fixes issue5925 by allow aborting a `hg amend --patch` call by saving
an empty patch file. This is similar to aborting of `hg amend` when commit
message is empty.
Test changes demonstrate the fix.
#require test-repo
Enable obsolescence to avoid the warning issue when obsmarker are found
$ cat << EOF >> $HGRCPATH
> [diff]
> git = yes
> [experimental]
> evolution=all
> EOF
Go back in the hg repo
$ cd $TESTDIR/..
$ for node in `hg log --rev 'not public() and ::. and not desc("# no-check-commit")' --template '{node|short}\n'`; do
> hg export $node | ${RUNTESTDIR}/../contrib/check-commit > ${TESTTMP}/check-commit.out
> if [ $? -ne 0 ]; then
> echo "Revision $node does not comply with rules"
> echo '------------------------------------------------------'
> cat ${TESTTMP}/check-commit.out
> echo
> fi
> done