tests/test-issue1802.t

match: avoid translating glob to matcher multiple times for large sets

For hgignore with many globs, the resulting regexp might not fit under the 20K
length limit. So the patterns need to be broken up in smaller pieces.

Before this change, the logic was re-starting the full process from scratch
for each smaller pieces, including the translation of globs into regexp.
Effectively doing the work over and over.

If the 20K limit is reached, we are likely in a case where there is many such
glob, so exporting them is especially expensive and we should be careful not
to do that work more than once.

To work around this, we now translate glob to regexp once and for all. Then,
we assemble the resulting individual regexp into valid blocks.

This raises a very significant performance win for large `.hgignore file`:

Before: ! wall 0.153153 comb 0.150000 user 0.150000 sys 0.000000 (median of 66)
After:  ! wall 0.059793 comb 0.060000 user 0.060000 sys 0.000000 (median of 100)

#require execbit

Create extension that can disable exec checks:

  $ cat > noexec.py <<EOF
  > from mercurial import extensions, util
  > def setflags(orig, f, l, x):
  >     pass
  > def checkexec(orig, path):
  >     return False
  > def extsetup(ui):
  >     extensions.wrapfunction(util, 'setflags', setflags)
  >     extensions.wrapfunction(util, 'checkexec', checkexec)
  > EOF

  $ hg init unix-repo
  $ cd unix-repo
  $ touch a
  $ hg add a
  $ hg commit -m 'unix: add a'
  $ hg clone . ../win-repo
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ chmod +x a
  $ hg commit -m 'unix: chmod a'
  $ hg manifest -v
  755 * a

  $ cd ../win-repo

  $ touch b
  $ hg add b
  $ hg commit -m 'win: add b'

  $ hg manifest -v
  644   a
  644   b

  $ hg pull
  pulling from $TESTTMP/unix-repo
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)
  new changesets 2d8bcf2dda39
  (run 'hg heads' to see heads, 'hg merge' to merge)

  $ hg manifest -v -r tip
  755 * a

Simulate a Windows merge:

  $ hg --config extensions.n=$TESTTMP/noexec.py merge --debug
    searching for copies back to rev 1
    unmatched files in local:
     b
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: a03b0deabf2b, local: d6fa54f68ae1+, remote: 2d8bcf2dda39
   a: update permissions -> e
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Simulate a Windows commit:

  $ hg --config extensions.n=$TESTTMP/noexec.py commit -m 'win: merge'

  $ hg manifest -v
  755 * a
  644   b

  $ cd ..