fix: ref_exists also checks git-svn remote ref variant for imported tags/branches

svn_mirror/db.py

@@ -103,8 +103,18 @@ class MappingDB:
         ).fetchall()
 
     def ref_exists(self, git_ref: str) -> bool:
+        # Also check the git-svn remote variant if this is a canonical ref
+        variants = [git_ref]
+        if git_ref.startswith("refs/tags/"):
+            variants.append("refs/remotes/origin/tags/" + git_ref[10:])
+        elif git_ref == "refs/heads/master":
+            variants.append("refs/remotes/origin/trunk")
+        elif git_ref.startswith("refs/heads/"):
+            variants.append("refs/remotes/origin/" + git_ref[11:])
         row = self.conn.execute(
-            "SELECT 1 FROM svn_to_git WHERE git_ref=?", (git_ref,)
+            "SELECT 1 FROM svn_to_git WHERE git_ref IN ({})".format(
+                ",".join("?" * len(variants))
+            ), variants
         ).fetchone()
         return row is not None