Add error checking for every occurance of rows.Next()

cmd/backend/articles_contributors.go

@@ -68,6 +68,10 @@ func (db *DB) GetArticleContributors(c *Config, articleID int64) ([]*User, error
 		contributors = append(contributors, contributor)
 	}
 
+	if err = rows.Err(); err != nil {
+		return nil, fmt.Errorf("error iterating over rows: %v", err)
+	}
+
 	return contributors, nil
 }