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.

#!/bin/sh

hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
touch b
hg add b
rm b
hg commit -A -m"comment #1" -d "1000000 0"