git-svn: fix delete+add branch tracking with empty files

Original bug report and test case by Björn Steinbrink.

Björn Steinbrink <B.Steinbrink@gmx.de> wrote:
> Hi Eric,
>
> seems that the empty symlink stuff gets confused about which revision to
> use when looking for the parent's file.
>
> r3 = f1a6fcf6b0a1c4a373d0b2b65a3d70700084f361 (tags/1.0.1)
> Found possible branch point: file:///home/doener/h/svn/tags/1.0 => file:///home/doener/h/svn/branches/1.0, 4
> Found branch parent: (1.0) 63ae640ba01014ecbb3df590999ed1fa5914545b
> Following parent with do_switch
> Successfully followed parent
> r5 = 26fcfef5bcced97ab74faf1af7341a2ae0d272aa (1.0)
> Found possible branch point: file:///home/doener/h/svn/branches/1.0 => file:///home/doener/h/svn/tags/1.0.1, 5
> Found branch parent: (tags/1.0.1) 26fcfef5bcced97ab74faf1af7341a2ae0d272aa
> Following parent with do_switch
> Scanning for empty symlinks, this may take a while if you have many empty files
> You may disable this with `git config svn.brokenSymlinkWorkaround false'.
> This may be done in a different terminal without restarting git svn
> Filesystem has no item: File not found: revision 3, path '/branches/1.0/file' at /usr/local/libexec/git-core/git-svn line 3318
>
> Note how it tries to look at revision 3 instead of revision 5 (which it
> correctly detected as the parent). The import succeeds when
> svn.brokenSymlinkWorkaround is set to false. Testcase below.

Signed-off-by: Eric Wong <normalperson@yhbt.net>

1 files changed, 192 insertions, 0 deletions

diff --git a/t/t9136/svn.dump b/t/t9136/svn.dump
new file mode 100644
index 0000000000..6b1ce0b2e8
--- /dev/null
+++ b/t/t9136/svn.dump
@@ -0,0 +1,192 @@
+SVN-fs-dump-format-version: 2
+
+UUID: eecae021-8f16-48da-969d-79beb8ae6ea5
+
+Revision-number: 0
+Prop-content-length: 56
+Content-length: 56
+
+K 8
+svn:date
+V 27
+2009-02-22T00:50:56.292890Z
+PROPS-END
+
+Revision-number: 1
+Prop-content-length: 106
+Content-length: 106
+
+K 7
+svn:log
+V 4
+init
+K 10
+svn:author
+V 8
+john.doe
+K 8
+svn:date
+V 27
+2009-02-22T00:50:57.192384Z
+PROPS-END
+
+Node-path: branches
+Node-kind: dir
+Node-action: add
+Prop-content-length: 10
+Content-length: 10
+
+PROPS-END
+
+
+Node-path: tags
+Node-kind: dir
+Node-action: add
+Prop-content-length: 10
+Content-length: 10
+
+PROPS-END
+
+
+Node-path: trunk
+Node-kind: dir
+Node-action: add
+Prop-content-length: 10
+Content-length: 10
+
+PROPS-END
+
+
+Node-path: trunk/file
+Node-kind: file
+Node-action: add
+Prop-content-length: 10
+Text-content-length: 0
+Text-content-md5: d41d8cd98f00b204e9800998ecf8427e
+Content-length: 10
+
+PROPS-END
+
+
+Revision-number: 2
+Prop-content-length: 105
+Content-length: 105
+
+K 7
+svn:log
+V 3
+1.0
+K 10
+svn:author
+V 8
+john.doe
+K 8
+svn:date
+V 27
+2009-02-22T00:50:58.124724Z
+PROPS-END
+
+Node-path: tags/1.0
+Node-kind: dir
+Node-action: add
+Node-copyfrom-rev: 1
+Node-copyfrom-path: trunk
+
+
+Revision-number: 3
+Prop-content-length: 111
+Content-length: 111
+
+K 7
+svn:log
+V 9
+1.0.1-bad
+K 10
+svn:author
+V 8
+john.doe
+K 8
+svn:date
+V 27
+2009-02-22T00:50:58.151727Z
+PROPS-END
+
+Node-path: tags/1.0.1
+Node-kind: dir
+Node-action: add
+Node-copyfrom-rev: 2
+Node-copyfrom-path: tags/1.0
+
+
+Revision-number: 4
+Prop-content-length: 111
+Content-length: 111
+
+K 7
+svn:log
+V 9
+Wrong tag
+K 10
+svn:author
+V 8
+john.doe
+K 8
+svn:date
+V 27
+2009-02-22T00:50:58.167427Z
+PROPS-END
+
+Node-path: tags/1.0.1
+Node-action: delete
+
+
+Revision-number: 5
+Prop-content-length: 113
+Content-length: 113
+
+K 7
+svn:log
+V 10
+1.0-branch
+K 10
+svn:author
+V 8
+john.doe
+K 8
+svn:date
+V 27
+2009-02-22T00:50:58.184498Z
+PROPS-END
+
+Node-path: branches/1.0
+Node-kind: dir
+Node-action: add
+Node-copyfrom-rev: 4
+Node-copyfrom-path: tags/1.0
+
+
+Revision-number: 6
+Prop-content-length: 113
+Content-length: 113
+
+K 7
+svn:log
+V 10
+1.0.1-good
+K 10
+svn:author
+V 8
+john.doe
+K 8
+svn:date
+V 27
+2009-02-22T00:50:58.200695Z
+PROPS-END
+
+Node-path: tags/1.0.1
+Node-kind: dir
+Node-action: add
+Node-copyfrom-rev: 5
+Node-copyfrom-path: branches/1.0
+
+