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.

     1

% init

     2

% commit

     3

adding base

     4

% qnew mqbase

     5

% qrefresh

     6

% qdiff

     7

diff -r 67e992f2c4f3 base

     8

--- a/base

     9

+++ b/base

    10

@@ -1,1 +1,1 @@ base

    11

-base

    12

+patched

    13

% qdiff dirname

    14

diff -r 67e992f2c4f3 base

    15

--- a/base

    16

+++ b/base

    17

@@ -1,1 +1,1 @@ base

    18

-base

    19

+patched