Merge pull request #1644 from mattermost/plt-1279-1

PLT-1279 Make sure posts in common threads are included in getPosts DB query

store/sql_post_store.go

@@ -571,7 +571,8 @@ func (s SqlPostStore) getParentsPosts(channelId string, offset int, limit int) S
 			            AND DeleteAt = 0
 			    ORDER BY CreateAt DESC
 			    LIMIT :Limit OFFSET :Offset) q3
-			    WHERE q3.RootId != '') q1 ON q1.RootId = q2.Id
+			    WHERE q3.RootId != '') q1
+			    ON q1.RootId = q2.Id OR q1.RootId = q2.RootId
 			WHERE
 			    ChannelId = :ChannelId2
 			        AND DeleteAt = 0

store/sql_post_store_test.go

@@ -445,7 +445,7 @@ func TestPostStoreGetPostsWtihDetails(t *testing.T) {
 		t.Fatal("invalid order")
 	}
 
-	if len(r1.Posts) != 5 { //the last 4, + o1 (o3 and o2a's parent)
+	if len(r1.Posts) != 6 { //the last 4, + o1 (o2a and o3's parent) + o2 (in same thread as o2a and o3)
 		t.Fatal("wrong size")
 	}