view tests/test-issue1502.t @ 30440:8c0c75aa3ff4

bdiff: give slight preference to longest matches in the middle of the B side

We already have a slight preference for matches close to the middle on the A
side. Now, do the same on the B side.

j is iterating the b range backwards and we thus accept a new j if the previous
match was in the upper half.

This makes the test-bhalf diff "correct". It obviously also gives more
preference to balanced recursion than to appending to sequences. That is kind
of correct, but will also unfortunately make some bundles bigger. No doubt, we
can also create examples where it will make them smaller ...

The bundle size for 4.0 (hg bundle --base null -r 4.0 x.hg) happens to go from
22803824 to 22806817 bytes - an 0.01% increase.

https://bz.mercurial-scm.org/1502

Initialize repository

  $ hg init foo
  $ touch foo/a && hg -R foo commit -A -m "added a"
  adding a

  $ hg clone foo foo1
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo "bar" > foo1/a && hg -R foo1 commit -m "edit a in foo1"
  $ echo "hi" > foo/a && hg -R foo commit -m "edited a foo"
  $ hg -R foo1 pull
  pulling from $TESTTMP/foo (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)

  $ hg -R foo1 book branchy
  $ hg -R foo1 book
   * branchy                   1:e3e522925eff

Pull. Bookmark should not jump to new head.

  $ echo "there" >> foo/a && hg -R foo commit -m "edited a again"
  $ hg -R foo1 pull
  pulling from $TESTTMP/foo (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  (run 'hg update' to get a working copy)

  $ hg -R foo1 book
   * branchy                   1:e3e522925eff