Merge branch 'bc/filter-branch'

* bc/filter-branch:
  filter-branch.sh: support nearly proper tag name filtering

1 files changed, 10 insertions, 4 deletions

diff --git a/Documentation/git-filter-branch.txt b/Documentation/git-filter-branch.txt
index 6454e49..8d80f0d 100644
--- a/Documentation/git-filter-branch.txt
+++ b/Documentation/git-filter-branch.txt
@@ -133,10 +133,16 @@ use "--tag-name-filter cat" to simply update the tags.  In this
 case, be very careful and make sure you have the old tags
 backed up in case the conversion has run afoul.
 +
-Note that there is currently no support for proper rewriting of
-tag objects; in layman terms, if the tag has a message or signature
-attached, the rewritten tag won't have it.  Sorry.  (It is by
-definition impossible to preserve signatures at any rate.)
+Nearly proper rewriting of tag objects is supported. If the tag has
+a message attached, a new tag object will be created with the same message,
+author, and timestamp. If the tag has a signature attached, the
+signature will be stripped. It is by definition impossible to preserve
+signatures. The reason this is "nearly" proper, is because ideally if
+the tag did not change (points to the same object, has the same name, etc.)
+it should retain any signature. That is not the case, signatures will always
+be removed, buyer beware. There is also no support for changing the
+author or timestamp (or the tag message for that matter). Tags which point
+to other tags will be rewritten to point to the underlying commit.
 
 --subdirectory-filter <directory>::
 	Only look at the history which touches the given subdirectory.