Cover all code paths in search_commits (#2087)

The search_commits method was only very lightly tested, meaning over
half of it was not covered. Write another test case, covering all code
paths.

github/MainClass.py

@@ -598,19 +598,15 @@ class Github:
         """
         assert isinstance(query, str), query
         url_parameters = dict()
-        if (
-            sort is not github.GithubObject.NotSet
-        ):  # pragma no branch (Should be covered)
+        if sort is not github.GithubObject.NotSet:
             assert sort in ("author-date", "committer-date"), sort
             url_parameters["sort"] = sort
-        if (
-            order is not github.GithubObject.NotSet
-        ):  # pragma no branch (Should be covered)
+        if order is not github.GithubObject.NotSet:
             assert order in ("asc", "desc"), order
             url_parameters["order"] = order
 
         query_chunks = []
-        if query:  # pragma no branch (Should be covered)
+        if query:
             query_chunks.append(query)
 
         for qualifier, value in qualifiers.items():

tests/Search.py

@@ -195,6 +195,15 @@ class Search(Framework.TestCase):
         )
         self.assertEqual(commits.totalCount, 3)
 
+    def testSearchCommits(self):
+        commits = self.g.search_commits(
+            query="hash:1265747e992ba7d34a469b6b2f527809f8bf7067",
+            sort="author-date",
+            order="asc",
+            merge="false",
+        )
+        self.assertEqual(commits.totalCount, 2)
+
     def testSearchTopics(self):
         topics = self.g.search_topics("python", repositories=">950")
         self.assertListKeyBegin(