sparse-revlog: only refine delta candidates in the sparse case (issue6006)
Starting with 5aef5afa8654, a valid delta parent might be "refined". This
allows repository using sparse-revlog to produce better delta chain by using
better intermediate snapshot base.
However, this refining step was performed in all cases, including for
repository not using sparse-revlog. This could produce a strange chain in the
general delta case and corrupted repository in the non-general delta case.
We now skip this step unless sparse-revlog is in use.
In issue 6006, Yuya Nishihara provided a test case using an external
repository, so we did not include it. Finding "laboratory" condition to
reproduce this case and implementing an efficient test reproducing it is a bit
tricky. We do not foresee to have the time to provide one by the release date.
Differential Revision: https://phab.mercurial-scm.org/D5197
$ cat > echo.py <<EOF
> #!$PYTHON
> from __future__ import absolute_import, print_function
> import os
> import sys
> try:
> import msvcrt
> msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
> msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
> except ImportError:
> pass
>
> for k in ('HG_FILE', 'HG_MY_ISLINK', 'HG_OTHER_ISLINK', 'HG_BASE_ISLINK'):
> print(k, os.environ[k])
> EOF
Create 2 heads containing the same file, once as
a file, once as a link. Bundle was generated with:
# hg init t
# cd t
# echo a > a
# hg ci -qAm t0 -d '0 0'
# echo l > l
# hg ci -qAm t1 -d '1 0'
# hg up -C 0
# ln -s a l
# hg ci -qAm t2 -d '2 0'
# echo l2 > l2
# hg ci -qAm t3 -d '3 0'
$ hg init t
$ cd t
$ hg -q unbundle "$TESTDIR/bundles/test-merge-symlinks.hg"
$ hg up -C 3
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
Merge them and display *_ISLINK vars
merge heads
$ hg merge --tool="\"$PYTHON\" ../echo.py"
merging l
HG_FILE l
HG_MY_ISLINK 1
HG_OTHER_ISLINK 0
HG_BASE_ISLINK 0
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
Test working directory symlink bit calculation wrt copies,
especially on non-supporting systems.
merge working directory
$ hg up -C 2
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg copy l l2
$ HGMERGE="\"$PYTHON\" ../echo.py" hg up 3
merging l2
HG_FILE l2
HG_MY_ISLINK 1
HG_OTHER_ISLINK 0
HG_BASE_ISLINK 0
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
$ cd ..