tests/test-diff-color

tests: don't match blank output lines as regexes in unified tests

Currently, the following unified test will pass:

  $ echo foo


A blank output line (a line containing just two spaces) will match any
output.

The patch modifies the unified test runner to ignore empty strings
strings when do regular expression matching.

#!/bin/sh

echo "[extensions]" >> $HGRCPATH
echo "color=" >> $HGRCPATH

hg init repo
cd repo
cat > a <<EOF
c
c
a
a
b
a
a
c
c
EOF
hg ci -Am adda
cat > a <<EOF
c
c
a
a
dd
a
a
c
c
EOF

echo '% default context'
hg diff --nodates --color=always

echo '% --unified=2'
hg diff --nodates -U 2  --color=always

echo '% diffstat'
hg diff --stat --color=always

echo "record=" >> $HGRCPATH
echo "[ui]" >> $HGRCPATH
echo "interactive=true" >> $HGRCPATH
echo "[diff]" >> $HGRCPATH
echo "git=True" >> $HGRCPATH

echo % record
chmod 0755 a
hg record --color=always -m moda a <<EOF
y
y
EOF
echo

echo "[extensions]" >> $HGRCPATH
echo "mq=" >> $HGRCPATH

hg rollback
echo % qrecord
hg qrecord --color=always -m moda patch <<EOF
y
y
EOF
echo