tests/test-clone-r

util._matcher: speed up regexp matching.

In 4babaa52badf, Benoit made a change that substantially slows matching
when a big .hgignore file is in play, because it calls into the regexp
matching engine potentially hundreds of times per file to be matched.

I've partly rolled back his change, so that we only call into the matcher
once per file, but preserved the ability to report a meaningful error
message if there's a syntax error in the regexp.

#!/bin/sh

hg init test
cd test
cat >>afile <<EOF
0
EOF
hg add afile
hg commit -m "0.0"
cat >>afile <<EOF
1
EOF
hg commit -m "0.1"
cat >>afile <<EOF
2
EOF
hg commit -m "0.2"
cat >>afile <<EOF
3
EOF
hg commit -m "0.3"
hg update -C 0
cat >>afile <<EOF
1
EOF
hg commit -m "1.1"
cat >>afile <<EOF
2
EOF
hg commit -m "1.2"
cat >fred <<EOF
a line
EOF
cat >>afile <<EOF
3
EOF
hg add fred
hg commit -m "1.3"
hg mv afile adifferentfile
hg commit -m "1.3m"
hg update -C 3
hg mv afile anotherfile
hg commit -m "0.3m"
hg debugindex .hg/store/data/afile.i
hg debugindex .hg/store/data/adifferentfile.i
hg debugindex .hg/store/data/anotherfile.i
hg debugindex .hg/store/data/fred.i
hg debugindex .hg/store/00manifest.i
hg verify
cd ..
for i in 0 1 2 3 4 5 6 7 8; do
   hg clone -r "$i" test test-"$i"
   cd test-"$i"
   hg verify
   cd ..
done
cd test-8
hg pull ../test-7
hg verify