fix 'convert' with single commit repositories
The attached patch passes the three 'convert' testcases, and also is
able to successfully convert the git.git repository.
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
a
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
a not present
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
destination directory: a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
a