a0a08d48d0
1 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Peter Baumann
|
61b472ed8b |
git svn: reset invalidates the memoized mergeinfo caches
Since v1.7.0-rc2~11 (git-svn: persistent memoization, 2010-01-30),
git-svn has maintained some private per-repository caches in
.git/svn/.caches to avoid refetching and recalculating some
mergeinfo-related information with every 'git svn fetch'.
This memoization can cause problems, e.g consider the following case:
SVN repo:
... - a - b - c - m <- trunk
\ /
d - e <- branch1
The Git import of the above repo is at commit 'a' and doesn't know about
the branch1. In case of an 'git svn rebase', only the trunk of the
SVN repo is imported. During the creation of the git commit 'm', git svn
uses the svn:mergeinfo property and tries to find the corresponding git
commit 'e' to create 'm' with 'c' and 'e' as parents. But git svn rebase
only imports the current branch so commit 'e' is not imported.
Therefore git svn fails to create commit 'm' as a merge commit, because one
of its parents is not known to git. The imported history looks like this:
... - a - b - c - m <- trunk
A later 'git svn fetch' to import all branches can't rewrite the commit 'm'
to add 'e' as a parent and to make it a real git merge commit, because it
was already imported.
That's why the imported history misses the merge and looks like this:
... - a - b - c - m <- trunk
\
d - e <- branch1
Right now the only known workaround for importing 'm' as a merge is to
force reimporting 'm' again from SVN, e.g. via
$ git svn reset --revision $(git find-rev $c)
$ git svn fetch
Sadly, this is where the behavior has regressed: git svn reset doesn't
invalidate the old mergeinfo cache, which is no longer valid for the
reimport, which leads to 'm' beeing imprted with only 'c' as parent.
As solution to this problem, this commit invalidates the mergeinfo cache
to force correct recalculation of the parents.
During development of this patch, several ways for invalidating the cache
where considered. One of them is to use Memoize::flush_cache, which will
call the CLEAR method on the underlying Memoize persistency implementation.
Sadly, neither Memoize::Storable nor the newer Memoize::YAML module
introduced in
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