amend: do not drop missing files (
issue5732)
samefile() can be wrong since wctx.manifest() does not include missing files,
whereas missing files should be preserved on commit.
fixbundle() {
grep -v 'saving bundle' | grep -v 'saved backup' | \
grep -v added | grep -v adding | \
grep -v "unable to find 'e' for patching" | \
grep -v "e: No such file or directory" | \
cat
}