Correctly handle schema-less URIs for remote fetch URL

Currently we don't deal with schema-less URIs like
`git@github.com:foo` at all resulting in a scenario where we append
them to the manifest repo URL.

In order to deal with this, we munge both the manifest URL and the
fetch URL into a format we like and proceed with that.

Bug: https://g-issues.gerritcodereview.com/issues/40010331
Change-Id: I7b79fc4ed276630fdbeb235b94e327b172f0879b
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/386954
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: Michael Kelly <mkelly@arista.com>
Commit-Queue: Mike Frysinger <vapier@google.com>

tests/test_manifest_xml.py

@@ -1128,3 +1128,32 @@ class ExtendProjectElementTests(ManifestParseTestCase):
         )
         self.assertEqual(len(manifest.projects), 1)
         self.assertEqual(manifest.projects[0].upstream, "bar")
+
+
+class NormalizeUrlTests(ManifestParseTestCase):
+    """Tests for normalize_url() in manifest_xml.py"""
+
+    def test_has_trailing_slash(self):
+        url = "http://foo.com/bar/baz/"
+        self.assertEqual(
+            "http://foo.com/bar/baz", manifest_xml.normalize_url(url)
+        )
+
+    def test_has_no_scheme(self):
+        """Deal with cases where we have no scheme, but we also
+        aren't dealing with the git SCP-like syntax
+        """
+        url = "foo.com/baf/bat"
+        self.assertEqual(url, manifest_xml.normalize_url(url))
+
+        url = "git@foo.com/baf/bat"
+        self.assertEqual(url, manifest_xml.normalize_url(url))
+
+        url = "/file/path/here"
+        self.assertEqual(url, manifest_xml.normalize_url(url))
+
+    def test_has_no_scheme_matches_scp_like_syntax(self):
+        url = "git@foo.com:bar/baf"
+        self.assertEqual(
+            "ssh://git@foo.com/bar/baf", manifest_xml.normalize_url(url)
+        )