grep: extend functionality, add man page entry, add unit test.
walkchangerevs now returns a two-tuple. Its behaviour is also
extensively commented.
The annotate command's getname function has been factored out to a new
function, trimname, so it can be shared between annotate and grep.
The behaviour of grep has been beefed up, so that it now performs a
number of useful functions.
#!/bin/sh
# No local source
hg clone a b
echo $?
# No remote source
hg clone http://127.0.0.1:3121/a b
echo $?
rm -rf b # work around bug with http clone
# Inaccessible source
mkdir a
chmod 000 a
hg clone a b
echo $?
# Inaccessible destination
mkdir b
cd b
hg init
hg clone . ../a
echo $?
cd ..
chmod 700 a
rm -rf a b
# Source of wrong type
mkfifo a
hg clone a b
echo $?
rm a
# Default destination, same directory
mkdir q
cd q
hg init
cd ..
hg clone q
true