Mercurial > hgsubversion
view notes/metadata.txt @ 1229:46523cdfd3b0 stable 1.6.3
pushmod: prepend "link " to base text for links
http://svn.apache.org/viewvc?view=revision&revision=1223036 exposes
what is arguably a bug in hgsubversion push code. Specifically, when
we are receiving text from the server in an editor, we prepend a "link
" to the text of symlinks when opening a file and strip it when
closing a file. We don't, however, prepend "link " to the base we use
when sending text changes to the server.
This was working before because prior to that revision, the first
thing subversion did was to check whether the entirety of the before
text or the entirety of the after text was less than 64 bytes. In
that case, it just sent the entirety of the after text as a single
insert operation. I'd expect most, but not all symlinks to fit under
the 64 byte limit, including the leading "link " text on the
subversion end.
After the change, the first thing subversion does is check for a
leading match that is more than 4 bytes long, or that is the full
length of the after text. In this case, it sends a copy operation for
the leading match, and then goes into the if < 64 bytes remaining send
the whole thing behavior. It also looks for trailing matches of more
than 4 bytes even in the <64 byte case, but that's not what breaks the
tests.
Incidentally, changing the destination of long symlinks was broken
even before this subversion change. This diff includes test additions
that cover that breakage.
| author | David Schleimer <dschleimer@gmail.com> |
|---|---|
| date | Thu, 07 Aug 2014 19:30:26 -0700 |
| parents | ba801f44d240 |
| children |
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Branches -------- In order to handle branches that are not immediate children of /branches/, the following information must be stored in the revmap: revision path Where path is the actual relative path of the branch in svn. An example, with the previous format for clarification: New | Old 3 <hash> trunk | 3 <hash> 4 <hash> branches/foo | 4 <hash> foo Tags ---- Note that if a tag is committed to, we can handle that case by making a branch and then marking it as deleted. The revmap line would look something like this: 10 <hash> tags/the_tag And the commit would be done on the hg branch 'modified-tag/the_tag'. Note that if this was 'tags/releases/1.0.0', then the branch would be 'modified-tag/releases/1.0.0'. Detecting Closing of Branches ----------------------------- Subversion users typically remove branches when done with them. This means that if a commit performs a delete operation on the '' path inside a branch, we can be sure that the branch no longer exists. The branch should then be marked as inactive. Closing Branches ---------------- As of this writing, Mercurial marks branches as inactive by merging them so they have no active heads. In order to mark a branch as closed, the active head on the branch will be used as the first parent of the new changeset, and the second changeset will be either the active head on the hg branch 'closed-branches' or be the nullrev. The commit to mark the branch as inactive will happen on the 'closed-branches' branch in Mercurial. Recovery -------- hgsubversion stores several pieces of essential metadata in .hg/svn/. In order to rebuild this data, the key 'convert_revision' should be stored in the extra dictionary of the converted revision. The key should contain data in the format: 'svn:<uuid>/abs/path@<rev>' where <uuid> is the repo UUID, /abs/path is the absolute path to the location the edits were made in Subversion (that is, if it was a trunk commit on /foo/trunk, then /foo/trunk is what gets stored here, even though the project root does not equal the repo root), and <rev> is the revision number of the change in Subversion. This key (and its contents) have been chosen to be compatible with the convert extension so that repos originally converted to hg using convert can be maintained using hgsubversion if desired. Tags (tag_info) can be reconstructed by listing the tags directory and then running log on each tag to determine its parent changeset. The last revision converted (last_rev) can be converted simply by using the highest revision number encountered while rebuilding the revision map. The legacy tag_locations file does not need to be replaced - it will be obsoleted as part of the long-term branch refactor. The url will have to be provided by the user. The uuid can be re-requested from the repository. branch_info can be rebuilt during the rebuild of the revision map by recording the revisions of all active heads of server-side branches. branch_info contains a map from branch: (parent_branch, parent_branch_rev, branch_created_rev)