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.
adding bar
adding foo
adding bomb
adding a.c
adding dir/a.o
adding dir/b.o
M dir/b.o
! a.c
! dir/a.o
? .hgignore
a.c: unsupported file type (type is fifo)
! a.c
# test absolute path through symlink outside repo
A f
# try symlink outside repo to file inside
abort: ../z not under root
# try cloning symlink in a subdir
1. commit a symlink
? a/b/c/demo
adding a/b/c/demo
2. clone it
1 files updated, 0 files merged, 0 files removed, 0 files unresolved