git-svn: fix fetch with deleted tag

Currently git-svn assumes that two tags created from the same
revision will have the same repo url, so it uses a ref to the
tag without checking that its url matches the current url.

This causes issues when fetching an svn repo where a tag was
created, deleted, and then recreated under the following
circumstances:

- Both tags were copied from the same revision.
- Both tags had the same name.
- Both tags had different repository paths.
- [Optional] Both tags have a file with the same name but
  different content.

When all four conditions are met, a checksum mismatch error
occurs because the content of two files with the same path
differs (see t/t9155--git-svn-fetch-deleted-tag.sh):

    Checksum mismatch: ChangeLog 065854....
    expected: ce771b....
         got: 9563fd....

When only the first three conditions are met, no error occurs
but the tag in git matches the first (deleted) tag instead of
the last (most recent) tag (see
t/t9156-git-svn-fetch-deleted-tag-2.sh).

The fix is to verify that the repo url for the ref matches the
current url.  If the urls do not match, then a "tail" is grown
on the tag name by appending a dash and rechecking the new ref's
repo url until either a matching repo url is found or a new tag
is created.

Signed-off-by: David D. Kilzer <ddkilzer@kilzer.net>
Acked-by: Eric Wong <normalperson@yhbt.net>

diff --git a/git-svn.perl b/git-svn.perl
index 39bcb45593e91bad14adb4b59a4d82b6821635cd..9b046b693fe82c992b3844bf6e8f79214dfa7a59 100755 (executable)
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -2963,14 +2963,25 @@ sub other_gs {
                $ref_id .= "\@$r";
                # just grow a tail if we're not unique enough :x
                $ref_id .= '-' while find_ref($ref_id);
-               print STDERR "Initializing parent: $ref_id\n" unless $::_q > 1;
                my ($u, $p, $repo_id) = ($new_url, '', $ref_id);
                if ($u =~ s#^\Q$url\E(/|$)##) {
                        $p = $u;
                        $u = $url;
                        $repo_id = $self->{repo_id};
                }
-               $gs = Git::SVN->init($u, $p, $repo_id, $ref_id, 1);
+               while (1) {
+                       # It is possible to tag two different subdirectories at
+                       # the same revision.  If the url for an existing ref
+                       # does not match, we must either find a ref with a
+                       # matching url or create a new ref by growing a tail.
+                       $gs = Git::SVN->init($u, $p, $repo_id, $ref_id, 1);
+                       my (undef, $max_commit) = $gs->rev_map_max(1);
+                       last if (!$max_commit);
+                       my ($url) = ::cmt_metadata($max_commit);
+                       last if ($url eq $gs->full_url);
+                       $ref_id .= '-';
+               }
+               print STDERR "Initializing parent: $ref_id\n" unless $::_q > 1;
        }
        $gs
 }

diff --git a/t/t9155-git-svn-fetch-deleted-tag.sh b/t/t9155-git-svn-fetch-deleted-tag.sh
new file mode 100755 (executable)
index 0000000..ef0ac87
--- /dev/null
+++ b/t/t9155-git-svn-fetch-deleted-tag.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+
+test_description='git svn fetch deleted tag'
+
+. ./lib-git-svn.sh
+
+test_expect_success 'setup svn repo' '
+       mkdir -p import/trunk/subdir &&
+       mkdir -p import/branches &&
+       mkdir -p import/tags &&
+       echo "base" >import/trunk/subdir/file &&
+       svn_cmd import -m "import for git svn" import "$svnrepo" &&
+       rm -rf import &&
+
+       svn_cmd mkdir --parents -m "create mybranch directory" "$svnrepo/branches/mybranch" &&
+       svn_cmd cp -m "create branch mybranch" "$svnrepo/trunk" "$svnrepo/branches/mybranch/trunk" &&
+
+       svn_cmd co "$svnrepo/trunk" svn_project &&
+       (cd svn_project &&
+               echo "trunk change" >>subdir/file &&
+               svn_cmd ci -m "trunk change" subdir/file &&
+
+               svn_cmd switch "$svnrepo/branches/mybranch/trunk" &&
+               echo "branch change" >>subdir/file &&
+               svn_cmd ci -m "branch change" subdir/file
+       ) &&
+
+       svn_cmd cp -m "create mytag attempt 1" -r5 "$svnrepo/trunk/subdir" "$svnrepo/tags/mytag" &&
+       svn_cmd rm -m "delete mytag attempt 1" "$svnrepo/tags/mytag" &&
+       svn_cmd cp -m "create mytag attempt 2" -r5 "$svnrepo/branches/mybranch/trunk/subdir" "$svnrepo/tags/mytag"
+'
+
+test_expect_success 'fetch deleted tags from same revision with checksum error' '
+       git svn init --stdlayout "$svnrepo" git_project &&
+       cd git_project &&
+       git svn fetch &&
+
+       git diff --exit-code mybranch:trunk/subdir/file tags/mytag:file &&
+       git diff --exit-code master:subdir/file tags/mytag^:file
+'
+
+test_done

diff --git a/t/t9156-git-svn-fetch-deleted-tag-2.sh b/t/t9156-git-svn-fetch-deleted-tag-2.sh
new file mode 100755 (executable)
index 0000000..5ce7e2f
--- /dev/null
+++ b/t/t9156-git-svn-fetch-deleted-tag-2.sh
@@ -0,0 +1,44 @@
+#!/bin/sh
+
+test_description='git svn fetch deleted tag 2'
+
+. ./lib-git-svn.sh
+
+test_expect_success 'setup svn repo' '
+       mkdir -p import/branches &&
+       mkdir -p import/tags &&
+       mkdir -p import/trunk/subdir1 &&
+       mkdir -p import/trunk/subdir2 &&
+       mkdir -p import/trunk/subdir3 &&
+       echo "file1" >import/trunk/subdir1/file &&
+       echo "file2" >import/trunk/subdir2/file &&
+       echo "file3" >import/trunk/subdir3/file &&
+       svn_cmd import -m "import for git svn" import "$svnrepo" &&
+       rm -rf import &&
+
+       svn_cmd co "$svnrepo/trunk" svn_project &&
+       (cd svn_project &&
+               echo "change1" >>subdir1/file &&
+               echo "change2" >>subdir2/file &&
+               echo "change3" >>subdir3/file &&
+               svn_cmd ci -m "change" .
+       ) &&
+
+       svn_cmd cp -m "create mytag 1" -r2 "$svnrepo/trunk/subdir1" "$svnrepo/tags/mytag" &&
+       svn_cmd rm -m "delete mytag 1" "$svnrepo/tags/mytag" &&
+       svn_cmd cp -m "create mytag 2" -r2 "$svnrepo/trunk/subdir2" "$svnrepo/tags/mytag" &&
+       svn_cmd rm -m "delete mytag 2" "$svnrepo/tags/mytag" &&
+       svn_cmd cp -m "create mytag 3" -r2 "$svnrepo/trunk/subdir3" "$svnrepo/tags/mytag"
+'
+
+test_expect_success 'fetch deleted tags from same revision with no checksum error' '
+       git svn init --stdlayout "$svnrepo" git_project &&
+       cd git_project &&
+       git svn fetch &&
+
+       git diff --exit-code master:subdir3/file tags/mytag:file &&
+       git diff --exit-code master:subdir2/file tags/mytag^:file &&
+       git diff --exit-code master:subdir1/file tags/mytag^^:file
+'
+
+test_done