don't return uninitialized memory from bdiff.blocks() bdiff.blocks() returns a dummy match at the end of both files; the length of that chunk is never set, so it will sometimes contain random heap garbage. There are apparently workarounds for this elsewhere: # bdiff sometimes gives huge matches past eof, this check eats them,

#!/bin/sh

# Test for changeset ba7c74081861
# (update dirstate correctly for non-branchmerge updates)
hg init a
cd a
echo a > a
hg add a
hg commit -m a
cd ..
hg clone a b
cd a
hg mv a b
hg commit -m move
echo b >> b
hg commit -m b
cd ../b
hg pull ../a
hg update