absorb: preserve changesets which were already empty
Most commands in Mercurial (commit, rebase, absorb itself) don’t create empty
changesets or drop them if they become empty. If there’s a changeset that’s
empty, it must be a deliberate choice of the user. At least it shouldn’t be
absorb’s responsibility to prune them. The fact that changesets that became
empty during absorb are pruned, is unaffected by this.
This case was found while writing patches which make it possible to configure
absorb and rebase to not drop empty changesets. Even without having such config
set, I think it’s valuable to preserve changesets which were already empty.
#require no-windows
$ . "$TESTDIR/remotefilelog-library.sh"
$ cat >> $HGRCPATH <<EOF
> [devel]
> remotefilelog.bg-wait=True
> EOF
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> EOF
$ echo x > x
$ echo z > z
$ hg commit -qAm x
$ echo x2 > x
$ echo y > y
$ hg commit -qAm y
$ echo w > w
$ rm z
$ hg commit -qAm w
$ hg bookmark foo
$ cd ..
# clone the repo
$ hgcloneshallow ssh://user@dummy/master shallow --noupdate
streaming all changes
2 files to transfer, 776 bytes of data
transferred 776 bytes in * seconds (*/sec) (glob)
searching for changes
no changes found
# Set the prefetchdays config to zero so that all commits are prefetched
# no matter what their creation date is. Also set prefetchdelay config
# to zero so that there is no delay between prefetches.
$ cd shallow
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> prefetchdays=0
> prefetchdelay=0
> EOF
$ cd ..
# prefetch a revision
$ cd shallow
$ hg prefetch -r 0
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ hg cat -r 0 x
x
# background prefetch on pull when configured
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> pullprefetch=bookmark()
> backgroundprefetch=True
> EOF
$ hg strip tip
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/6b4b6f66ef8c-b4b8bdaf-backup.hg (glob)
$ clearcache
$ hg pull
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
updating bookmark foo
added 1 changesets with 0 changes to 0 files
new changesets 6b4b6f66ef8c
(run 'hg update' to get a working copy)
prefetching file contents
$ find $CACHEDIR -type f | sort
$TESTTMP/hgcache/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/ef95c5376f34698742fe34f315fd82136f8f68c0
$TESTTMP/hgcache/master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca
$TESTTMP/hgcache/master/af/f024fe4ab0fece4091de044c58c9ae4233383a/bb6ccd5dceaa5e9dc220e0dad65e051b94f69a2c
$TESTTMP/hgcache/repos
# background prefetch with repack on pull when configured
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> backgroundrepack=True
> EOF
$ hg strip tip
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/6b4b6f66ef8c-b4b8bdaf-backup.hg (glob)
$ clearcache
$ hg pull
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
updating bookmark foo
added 1 changesets with 0 changes to 0 files
new changesets 6b4b6f66ef8c
(run 'hg update' to get a working copy)
prefetching file contents
$ find $CACHEDIR -type f | sort
$TESTTMP/hgcache/master/packs/6e8633deba6e544e5f8edbd7b996d6e31a2c42ae.histidx
$TESTTMP/hgcache/master/packs/6e8633deba6e544e5f8edbd7b996d6e31a2c42ae.histpack
$TESTTMP/hgcache/master/packs/8ce5ab3745465ab83bba30a7b9c295e0c8404652.dataidx
$TESTTMP/hgcache/master/packs/8ce5ab3745465ab83bba30a7b9c295e0c8404652.datapack
$TESTTMP/hgcache/repos
# background prefetch with repack on update when wcprevset configured
$ clearcache
$ hg up -r 0
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ find $CACHEDIR -type f | sort
$TESTTMP/hgcache/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0
$TESTTMP/hgcache/master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a
$TESTTMP/hgcache/repos
$ hg up -r 1
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
2 files fetched over 2 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> bgprefetchrevs=.::
> EOF
$ clearcache
$ hg up -r 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
* files fetched over * fetches - (* misses, 0.00% hit ratio) over *s (glob)
$ find $CACHEDIR -type f | sort
$TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histidx
$TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histpack
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.dataidx
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.datapack
$TESTTMP/hgcache/repos
# Ensure that file 'w' was prefetched - it was not part of the update operation and therefore
# could only be downloaded by the background prefetch
$ hg debugdatapack `ls -ct $TESTTMP/hgcache/master/packs/*.datapack | head -n 1`
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407:
w:
Node Delta Base Delta Length Blob Size
bb6ccd5dceaa 000000000000 2 2
Total: 2 2 (0.0% bigger)
x:
Node Delta Base Delta Length Blob Size
ef95c5376f34 000000000000 3 3
1406e7411862 ef95c5376f34 14 2
Total: 17 5 (240.0% bigger)
y:
Node Delta Base Delta Length Blob Size
076f5e2225b3 000000000000 2 2
Total: 2 2 (0.0% bigger)
z:
Node Delta Base Delta Length Blob Size
69a1b6752270 000000000000 2 2
Total: 2 2 (0.0% bigger)
# background prefetch with repack on commit when wcprevset configured
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> bgprefetchrevs=0::
> EOF
$ clearcache
$ find $CACHEDIR -type f | sort
$ echo b > b
.. The following output line about files fetches is globed because it is
.. flaky, the core the test is checked when checking the cache dir, so
.. hopefully this flakyness is not hiding any actual bug.
$ hg commit -qAm b
* files fetched over 1 fetches - (* misses, 0.00% hit ratio) over *s (glob) (?)
$ hg bookmark temporary
$ find $CACHEDIR -type f | sort
$TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histidx
$TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histpack
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.dataidx
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.datapack
$TESTTMP/hgcache/repos
# Ensure that file 'w' was prefetched - it was not part of the commit operation and therefore
# could only be downloaded by the background prefetch
$ hg debugdatapack `ls -ct $TESTTMP/hgcache/master/packs/*.datapack | head -n 1`
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407:
w:
Node Delta Base Delta Length Blob Size
bb6ccd5dceaa 000000000000 2 2
Total: 2 2 (0.0% bigger)
x:
Node Delta Base Delta Length Blob Size
ef95c5376f34 000000000000 3 3
1406e7411862 ef95c5376f34 14 2
Total: 17 5 (240.0% bigger)
y:
Node Delta Base Delta Length Blob Size
076f5e2225b3 000000000000 2 2
Total: 2 2 (0.0% bigger)
z:
Node Delta Base Delta Length Blob Size
69a1b6752270 000000000000 2 2
Total: 2 2 (0.0% bigger)
# background prefetch with repack on rebase when wcprevset configured
$ hg up -r 2
3 files updated, 0 files merged, 2 files removed, 0 files unresolved
(leaving bookmark temporary)
$ clearcache
$ find $CACHEDIR -type f | sort
.. The following output line about files fetches is globed because it is
.. flaky, the core the test is checked when checking the cache dir, so
.. hopefully this flakyness is not hiding any actual bug.
$ hg rebase -s temporary -d foo
rebasing 3:d9cf06e3b5b6 "b" (temporary tip)
saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/d9cf06e3b5b6-e5c3dc63-rebase.hg
? files fetched over ? fetches - (? misses, 0.00% hit ratio) over *s (glob)
$ find $CACHEDIR -type f | sort
$TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histidx
$TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histpack
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.dataidx
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.datapack
$TESTTMP/hgcache/repos
# Ensure that file 'y' was prefetched - it was not part of the rebase operation and therefore
# could only be downloaded by the background prefetch
$ hg debugdatapack `ls -ct $TESTTMP/hgcache/master/packs/*.datapack | head -n 1`
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407:
w:
Node Delta Base Delta Length Blob Size
bb6ccd5dceaa 000000000000 2 2
Total: 2 2 (0.0% bigger)
x:
Node Delta Base Delta Length Blob Size
ef95c5376f34 000000000000 3 3
1406e7411862 ef95c5376f34 14 2
Total: 17 5 (240.0% bigger)
y:
Node Delta Base Delta Length Blob Size
076f5e2225b3 000000000000 2 2
Total: 2 2 (0.0% bigger)
z:
Node Delta Base Delta Length Blob Size
69a1b6752270 000000000000 2 2
Total: 2 2 (0.0% bigger)
# Check that foregound prefetch with no arguments blocks until background prefetches finish
$ hg up -r 3
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ clearcache
$ hg prefetch --repack
waiting for lock on prefetching in $TESTTMP/shallow held by process * on host * (glob) (?)
got lock after * seconds (glob) (?)
(running background incremental repack)
* files fetched over 1 fetches - (* misses, 0.00% hit ratio) over *s (glob) (?)
$ find $CACHEDIR -type f | sort
$TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histidx
$TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histpack
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.dataidx
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.datapack
$TESTTMP/hgcache/repos
# Ensure that files were prefetched
$ hg debugdatapack `ls -ct $TESTTMP/hgcache/master/packs/*.datapack | head -n 1`
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407:
w:
Node Delta Base Delta Length Blob Size
bb6ccd5dceaa 000000000000 2 2
Total: 2 2 (0.0% bigger)
x:
Node Delta Base Delta Length Blob Size
ef95c5376f34 000000000000 3 3
1406e7411862 ef95c5376f34 14 2
Total: 17 5 (240.0% bigger)
y:
Node Delta Base Delta Length Blob Size
076f5e2225b3 000000000000 2 2
Total: 2 2 (0.0% bigger)
z:
Node Delta Base Delta Length Blob Size
69a1b6752270 000000000000 2 2
Total: 2 2 (0.0% bigger)
# Check that foreground prefetch fetches revs specified by '. + draft() + bgprefetchrevs + pullprefetch'
$ clearcache
$ hg prefetch --repack
waiting for lock on prefetching in $TESTTMP/shallow held by process * on host * (glob) (?)
got lock after * seconds (glob) (?)
(running background incremental repack)
* files fetched over 1 fetches - (* misses, 0.00% hit ratio) over *s (glob) (?)
$ find $CACHEDIR -type f | sort
$TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histidx
$TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histpack
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.dataidx
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.datapack
$TESTTMP/hgcache/repos
# Ensure that files were prefetched
$ hg debugdatapack `ls -ct $TESTTMP/hgcache/master/packs/*.datapack | head -n 1`
$TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407:
w:
Node Delta Base Delta Length Blob Size
bb6ccd5dceaa 000000000000 2 2
Total: 2 2 (0.0% bigger)
x:
Node Delta Base Delta Length Blob Size
ef95c5376f34 000000000000 3 3
1406e7411862 ef95c5376f34 14 2
Total: 17 5 (240.0% bigger)
y:
Node Delta Base Delta Length Blob Size
076f5e2225b3 000000000000 2 2
Total: 2 2 (0.0% bigger)
z:
Node Delta Base Delta Length Blob Size
69a1b6752270 000000000000 2 2
Total: 2 2 (0.0% bigger)
# Test that if data was prefetched and repacked we dont need to prefetch it again
# It ensures that Mercurial looks not only in loose files but in packs as well
$ hg prefetch --repack
(running background incremental repack)