Also ensure 2-way sync of remote bookmarks to proxy

... rather than only adding remote ones locally and never deleting.
In particular, makes fetch --prune work.

Fixes felipec/git-remote-hg#15

git-remote-hg

@@ -371,8 +371,19 @@ def fixup_user(user):
 
 def updatebookmarks(repo, peer):
     remotemarks = peer.listkeys('bookmarks')
-    localmarks = repo._bookmarks
 
+    # delete bookmarks locally that disappeared on remote
+    localmarks = bookmarks.listbookmarks(repo)
+    remote = set(remotemarks.keys())
+    local = set(localmarks.keys())
+    for bmark in local - remote:
+        bookmarks.pushbookmark(repo, bmark, localmarks[bmark], '')
+        # also delete private ref
+        pbookmark = '%s/bookmarks/%s' % (prefix, bmark)
+        subprocess.call(['git', 'update-ref', '-d', pbookmark])
+
+    # now add or update remote bookmarks to local, if any
+    localmarks = repo._bookmarks
     if not remotemarks:
         return
 
@@ -1320,8 +1331,8 @@ def main(args):
     dry_run = False
     notes = set()
 
-    repo = get_repo(url, alias)
     prefix = 'refs/hg/%s' % alias
+    repo = get_repo(url, alias)
 
     if not is_tmp:
         fix_path(alias, peer or repo, url)

test/main.t

@@ -783,6 +783,35 @@ test_expect_success 'remote double failed push' '
 	test_expect_code 1 git push
 	)
 '
+test_expect_success 'fetch prune' '
+	test_when_finished "rm -rf gitrepo hgrepo" &&
+
+	(
+	hg init hgrepo &&
+	cd hgrepo &&
+	echo zero > content &&
+	hg add content &&
+	hg commit -m zero &&
+	echo feature-a > content &&
+	hg commit -m feature-a
+	hg bookmark feature-a
+	) &&
+
+	git clone "hg::hgrepo" gitrepo &&
+	check gitrepo origin/feature-a feature-a &&
+
+	(
+	cd hgrepo &&
+	hg bookmark -d feature-a
+	) &&
+
+	(
+	cd gitrepo &&
+	git fetch --prune origin
+	git branch -a > out &&
+	! grep feature-a out
+	)
+'
 
 test_expect_success 'clone remote with null bookmark, then push' '
 	test_when_finished "rm -rf gitrepo* hgrepo*" &&