* admin/notes/bzr: Add section on undoing a bzr remove.

1 files changed, 24 insertions, 0 deletions

diff --git a/admin/notes/bzr b/admin/notes/bzr
index 07a3c6dd09f..11f0af17a3b 100644
--- a/admin/notes/bzr
+++ b/admin/notes/bzr
@@ -134,3 +134,27 @@ right thing to do is merge everything else, resolve the conflict by
 choosing either the trunk or branch version, then run `make -C lisp
 autoloads' to update the md5sums to the correct trunk value before
 committing.
+
+* Re-adding a file that has been removed from the repository
+
+It's easy to get this wrong. Let's suppose you've done:
+
+bzr remove file; bzr commit
+
+and now, sometime later, you realize this was a mistake and file needs
+to be brought back.  DON'T just do:
+
+bzr add file; bzr commit
+
+This restores file, but without its history (`bzr log file' will be
+very short).  This is because file gets re-added with a new file-id
+(use `bzr file-id file' to see the id).
+
+Insteading of adding the file, try:
+
+bzr revert -rN file; bzr commit
+
+where revision N+1 is the one where file was removed.
+
+You could also try `bzr add --file-ids-from', if you have a copy of
+another branch where file still exists.