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
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 --all
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 merge 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 "%%% revert should fail"
hg revert --all
echo "%%% revert should be ok now"
hg revert -r2 --all
echo "%%% should show b unknown and a marked modified (merged)"
hg status
echo "%%% should show foo-b"
cat a