alloc_ref_from_str(): factor out a common pattern of alloc_ref from string

diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index ea59015baa2507fdc8fe77d1c77ebdb2d5db2fa7..333f6a8f3b783d46a0ce3b2f59bae152936cd11c 100755 (executable)
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -406,8 +406,22 @@ if [ "$filter_tag_name" ]; then
                echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
 
                if [ "$type" = "tag" ]; then
-                       # Warn that we are not rewriting the tag object itself.
-                       warn "unreferencing tag object $sha1t"
+                       new_sha1=$(git cat-file tag "$ref" |
+                               sed -n \
+                                   -e "1,/^$/{
+                                         s/^object .*/object $new_sha1/
+                                         s/^type .*/type commit/
+                                         s/^tag .*/tag $new_ref/
+                                       }" \
+                                   -e '/^-----BEGIN PGP SIGNATURE-----/q' \
+                                   -e 'p' |
+                               git mktag) ||
+                               die "Could not create new tag object for $ref"
+                       if git cat-file tag "$ref" | \
+                          grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
+                       then
+                               warn "gpg signature stripped from tag object $sha1t"
+                       fi
                fi
 
                git update-ref "refs/tags/$new_ref" "$new_sha1" ||