use 'x is None' instead of 'x == None'
The built-in None object is a singleton and it is therefore safe to
compare memory addresses with is. It is also faster, how much depends
on the object being compared. For a simple type like str I get:
| s = "foo" | s = None
----------+-----------+----------
s == None | 0.25 usec | 0.21 usec
s is None | 0.17 usec | 0.17 usec
#!/bin/sh
echo % prepare repo
hg init a
cd a
echo "some text" > FOO.txt
echo "another text" > bar.txt
echo "more text" > QUICK.txt
hg add
hg ci -mtest1
echo
echo % verify
hg verify
echo
echo % introduce some bugs in repo
cd .hg/store/data
mv _f_o_o.txt.i X_f_o_o.txt.i
mv bar.txt.i xbar.txt.i
rm _q_u_i_c_k.txt.i
echo
echo % verify
hg verify
cd ..
echo % test revlog corruption
hg init b
cd b
touch a
hg add a
hg ci -m a
echo 'corrupted' > b
head -c 20 .hg/store/data/a.i > start
cat start b > .hg/store/data/a.i
echo
echo % verify
hg verify
exit 0