fix backtrace printed when cannot get lock.
change lock error handling code so exceptions have useful info and
exception handling in one place.
add test case for when cannot get lock.
#!/bin/sh
hg init
echo foo > a
hg add a
hg commit -m "1" -d "1000000 0"
echo bar > b
hg add b
hg remove a
echo "%%% should show a removed and b added"
hg status
echo "reverting..."
hg revert
echo "%%% should show b unknown and a back to normal"
hg status
rm b
hg co -C 0
echo foo-a > a
hg commit -m "2a" -d "1000000 0"
hg co -C 0
echo foo-b > a
hg commit -m "2b" -d "1000000 0"
HGMERGE=true hg update -m 1
echo "%%% should show foo-b"
cat a
echo bar > b
hg add b
rm a
hg remove a
echo "%%% should show a removed and b added"
hg status
echo "reverting..."
hg revert
echo "%%% should show b unknown and a marked modified (merged)"
hg status
echo "%%% should show foo-b"
cat a