add a warning and a related todo

arising from a conversation at FOSSY

diff --git a/doc/tips/splitting_a_repository.mdwn b/doc/tips/splitting_a_repository.mdwn
index cd94785760debd6d6fdebba92eee940192da42e2..d20497c74da50aa31368a91277515688b15b7109 100644 (file)
--- a/doc/tips/splitting_a_repository.mdwn
+++ b/doc/tips/splitting_a_repository.mdwn
@@ -70,6 +70,9 @@ Finally the annexed file contents need to be copied to the new repository:
        # Fix up annex links to content and make sure it's all ok.
        git annex fsck
 
+Warning: This method of copying the annexed file contents and dropping
+the unused ones causes the git-annex branch to log information.
+
 # alternative older method
 
 Here is another way to do it. Suppose the old big repo is at `~/oldrepo`:

diff --git a/doc/todo/filter-branch_for_objects.mdwn b/doc/todo/filter-branch_for_objects.mdwn
new file mode 100644 (file)
index 0000000..3483470
--- /dev/null
+++ b/doc/todo/filter-branch_for_objects.mdwn
@@ -0,0 +1,14 @@
+`git-annex filter-branch` can be used to split a git-annex repository.
+However, the approach in [[tips/splitting_a_repository]] then copies all
+objects into the new repository and drops unused objects. And dropunused
+updates location log in that situation, even when the location log didn't
+exist in that repository before. So, that approach leaks information about
+objects that were in the original repository into the split repository.
+
+Splitting a git-annex repository is something that, when you need to do it,
+you may have good reasons to want to avoid any such leakage of
+information.
+
+So perhaps add a feature that copies only the needed objects over to the
+split repository? Or update the tip with a better method that avoids this
+problem. --[[Joey]]