convert: add a mode where mercurial_sink skips empty revisions.
The getchanges function of some converter_source classes can return
some false positives. I.e. they sometimes claim that a file "foo"
was changed in some revision, even though its contents are still the
same.
convert_svn is particularly bad, but I think this can also happen with
convert_cvs and, at least in theory, with mercurial_source.
For regular conversions this is not really a problem - as long as
getfile returns the right contents, we'll get a converted revision
with the right contents. But when we use --filemap, this could lead
to superfluous revisions being converted.
Instead of fixing every converter_source, I decided to change
mercurial_sink to work around this problem.
When --filemap is used, we're interested only in revisions that touch
some specific files. If a revision doesn't change any of these files,
then we're not interested in it (at least for revisions with a single
parent; merges are special).
For mercurial_sink, we abuse this property and rollback a commit if
the manifest text hasn't changed. This avoids duplicating the logic
from localrepo.filecommit to detect unchanged files.
% init
% setup
% delete an empty directory
empty_dir
Removing directory empty_dir
directory
r1
% delete an untracked directory
untracked_dir/untracked_file1
untracked_dir/untracked_file2
Removing file untracked_dir/untracked_file1
Removing file untracked_dir/untracked_file2
Removing directory untracked_dir
directory
r1
% delete an untracked file
untracked_file
Removing file untracked_file
directory
r1
% delete an untracked file in a tracked directory
directory/untracked_file
Removing file directory/untracked_file
directory
r1
% delete nested directories
untracked_directory/nested_directory
Removing directory untracked_directory/nested_directory
Removing directory untracked_directory
directory
r1
% delete nested directories from a subdir
untracked_directory/nested_directory
Removing directory untracked_directory/nested_directory
Removing directory untracked_directory
directory
r1
% delete only part of the tree
untracked_directory/nested_directory
Removing directory untracked_directory/nested_directory
Removing directory untracked_directory
directory
r1
directory/untracked_file
% skip ignored files if --all not specified
directory
ignored
r1
ignored
Removing file ignored
directory
r1
% abort with missing files until we support name mangling filesystems
refused to run
untracked_file still around
untracked_file
refused to run
untracked_file still around
Removing file untracked_file
directory
r1
% skip excluded files
directory
excluded_file
r1
% skip files in excluded dirs
directory
excluded_dir
r1
file
% skip excluded empty dirs
directory
excluded_dir
r1
% skip patterns