hgweb: don't raise an exception when displying empty repos
The nullid node claims it's in the default branch, but the branch dict
is empty. This fixes the main symptom from issue696, but we may want
to set branchtags()['default'] = nullid somewhere for empty repos.
#!/bin/sh
mkdir t
cd t
hg init
echo "added file1" > file1
echo "added file2" > file2
hg add file1 file2
hg commit -m "added file1 and file2" -d "1000000 0" -u user
echo "changed file1" >> file1
hg commit -m "changed file1" -d "1000000 0" -u user
hg -q log
hg id
hg update -C 0
hg id
echo "changed file1" >> file1
hg id
hg revert --all
hg diff
hg status
hg id
hg update
hg diff
hg status
hg id
hg update -C 0
echo "changed file1" >> file1
hg update
hg diff
hg status
hg id
hg revert --all
hg diff
hg status
hg id
hg revert -r tip --all
hg diff
hg status
hg id
hg update -C
hg diff
hg status
hg id