Bug 1846705: Fix Updatebot Tag tracking r=jewilde

Always sort by creatordate, so we get the most recent tag at the end.
Stop using the Github API, because we can't sort by creatordate.
Unify the code paths to avoid duplication

Differential Revision: https://phabricator.services.mozilla.com/D188263

python/mozbuild/mozbuild/vendor/host_base.py

@@ -33,25 +33,28 @@ class BaseHost:
                 check=True,
             )
             os.chdir("/".join([temp_repo_clone, self.manifest["origin"]["name"]]))
-            if revision == "HEAD":
+            revision_arg = []
+            if revision and revision != "HEAD":
+                revision_arg = [revision]
+
+            try:
+                print(
+                    ["git", "--no-pager", "tag", "-l", "--sort=creatordate"]
+                    + revision_arg
+                )
                 tag = subprocess.run(
-                    ["git", "--no-pager", "tag", "--sort=creatordate"],
+                    ["git", "--no-pager", "tag", "-l", "--sort=creatordate"]
+                    + revision_arg,
                     stdout=subprocess.PIPE,
                     stderr=subprocess.PIPE,
                     universal_newlines=True,
                     check=True,
                 ).stdout.splitlines()[-1]
-            else:
+            except IndexError:  # 0 lines of output, the tag does not exist
-                try:
+                if revision:
-                    tag = subprocess.run(
-                        ["git", "--no-pager", "tag", "-l", revision],
-                        stdout=subprocess.PIPE,
-                        stderr=subprocess.PIPE,
-                        universal_newlines=True,
-                        check=True,
-                    ).stdout.splitlines()[-1]
-                except IndexError:  # 0 lines of output, the tag does not exist
                     raise Exception(f"Requested tag {revision} not found in source.")
+                else:
+                    raise Exception("No tags found in source.")
 
             tag_timestamp = subprocess.run(
                 [

python/mozbuild/mozbuild/vendor/host_github.py

@@ -21,14 +21,6 @@ class GitHubHost(BaseHost):
         info = self.api_get(f"commits/{revision}")
         return (info["sha"], info["commit"]["committer"]["date"])
 
-    def upstream_tag(self, tag):
-        """Github API allows using a tag name with the commits API."""
-        if tag == "HEAD":  # Checking for latest tag
-            info = self.api_get("tags")
-            tag = info[0]["name"]
-        sha, timestamp = self.upstream_commit(tag)
-        return tag, timestamp
-
     def upstream_snapshot(self, revision):
         return "/".join(
             [self.manifest["vendoring"]["url"], "archive", revision + ".tar.gz"]