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.
test sparse
$ hg init myrepo
$ cd myrepo
$ cat >> $HGRCPATH <<EOF
> [extensions]
> sparse=
> purge=
> strip=
> rebase=
> EOF
$ echo a > index.html
$ echo x > data.py
$ echo z > readme.txt
$ cat > base.sparse <<EOF
> [include]
> *.sparse
> EOF
$ hg ci -Aqm 'initial'
$ cat > webpage.sparse <<EOF
> %include base.sparse
> [include]
> *.html
> EOF
$ hg ci -Aqm 'initial'
Import a rules file against a 'blank' sparse profile
$ cat > $TESTTMP/rules_to_import <<EOF
> [include]
> *.py
> EOF
$ hg debugsparse --import-rules $TESTTMP/rules_to_import
$ ls -A
.hg
data.py
$ hg debugsparse --reset
$ rm .hg/sparse
$ cat > $TESTTMP/rules_to_import <<EOF
> %include base.sparse
> [include]
> *.py
> EOF
$ hg debugsparse --import-rules $TESTTMP/rules_to_import
$ ls -A
.hg
base.sparse
data.py
webpage.sparse
$ hg debugsparse --reset
$ rm .hg/sparse
Start against an existing profile; rules *already active* should be ignored
$ hg debugsparse --enable-profile webpage.sparse
$ hg debugsparse --include *.py
$ cat > $TESTTMP/rules_to_import <<EOF
> %include base.sparse
> [include]
> *.html
> *.txt
> [exclude]
> *.py
> EOF
$ hg debugsparse --import-rules $TESTTMP/rules_to_import
$ ls -A
.hg
base.sparse
index.html
readme.txt
webpage.sparse
$ cat .hg/sparse
%include webpage.sparse
[include]
*.py
*.txt
[exclude]
*.py
$ hg debugsparse --reset
$ rm .hg/sparse
Same tests, with -Tjson enabled to output summaries
$ cat > $TESTTMP/rules_to_import <<EOF
> [include]
> *.py
> EOF
$ hg debugsparse --import-rules $TESTTMP/rules_to_import -Tjson
[
{
"exclude_rules_added": 0,
"files_added": 0,
"files_conflicting": 0,
"files_dropped": 4,
"include_rules_added": 1,
"profiles_added": 0
}
]
$ hg debugsparse --reset
$ rm .hg/sparse
$ cat > $TESTTMP/rules_to_import <<EOF
> %include base.sparse
> [include]
> *.py
> EOF
$ hg debugsparse --import-rules $TESTTMP/rules_to_import -Tjson
[
{
"exclude_rules_added": 0,
"files_added": 0,
"files_conflicting": 0,
"files_dropped": 2,
"include_rules_added": 1,
"profiles_added": 1
}
]
$ hg debugsparse --reset
$ rm .hg/sparse
$ hg debugsparse --enable-profile webpage.sparse
$ hg debugsparse --include *.py
$ cat > $TESTTMP/rules_to_import <<EOF
> %include base.sparse
> [include]
> *.html
> *.txt
> [exclude]
> *.py
> EOF
$ hg debugsparse --import-rules $TESTTMP/rules_to_import -Tjson
[
{
"exclude_rules_added": 1,
"files_added": 1,
"files_conflicting": 0,
"files_dropped": 1,
"include_rules_added": 1,
"profiles_added": 0
}
]
If importing results in no new rules being added, no refresh should take place!
$ cat > $TESTTMP/trap_sparse_refresh.py <<EOF
> from mercurial import error, sparse
> def extsetup(ui):
> def abort_refresh(*args, **kwargs):
> raise error.Abort('sparse._refresh called!')
> sparse.refreshwdir = abort_refresh
> EOF
$ cat >> $HGRCPATH <<EOF
> [extensions]
> trap_sparse_refresh=$TESTTMP/trap_sparse_refresh.py
> EOF
$ cat > $TESTTMP/rules_to_import <<EOF
> [include]
> *.py
> EOF
$ hg debugsparse --import-rules $TESTTMP/rules_to_import
If an exception is raised during refresh, restore the existing rules again.
$ cat > $TESTTMP/rules_to_import <<EOF
> [exclude]
> *.html
> EOF
$ hg debugsparse --import-rules $TESTTMP/rules_to_import
abort: sparse._refresh called!
[255]
$ cat .hg/sparse
%include webpage.sparse
[include]
*.py
*.txt
[exclude]
*.py