[reddit] respect 'comments:0' for single submissions (#429)

gallery_dl/extractor/reddit.py

@@ -129,8 +129,15 @@ class RedditSubmissionExtractor(RedditExtractor):
                r"redd\.it"
                r")/([a-z0-9]+)")
     test = (
-        ("https://www.reddit.com/r/lavaporn/comments/2a00np/", {
-            "pattern": r"https?://i\.imgur\.com/AaAUCgy\.jpg",
+        ("https://www.reddit.com/r/lavaporn/comments/8cqhub/", {
+            "pattern": r"https://",
+            "count": 3,
+        }),
+        # ignore submission comments (#429)
+        ("https://www.reddit.com/r/lavaporn/comments/8cqhub/", {
+            "options": (("comments", 0),),
+            "pattern": r"https://c2.staticflickr.com/8/7272/\w+_k.jpg",
+            "count": 1,
         }),
         ("https://old.reddit.com/r/lavaporn/comments/2a00np/"),
         ("https://np.reddit.com/r/lavaporn/comments/2a00np/"),
@@ -202,7 +209,7 @@ class RedditAPI():
         link_id = "t3_" + submission_id if self.morecomments else None
         submission, comments = self._call(endpoint, {"limit": self.comments})
         return (submission["data"]["children"][0]["data"],
-                self._flatten(comments, link_id))
+                self._flatten(comments, link_id) if self.comments else None)
 
     def submissions_subreddit(self, subreddit, params):
         """Collect all (submission, comments)-tuples of a subreddit"""