allow rewhere to pass nil and return unscope(:where)

Author: a5-stable

activerecord/lib/active_record/relation/query_methods.rb

@@ -944,6 +944,8 @@ def where!(opts, *rest) # :nodoc:
     # This is short-hand for <tt>unscope(where: conditions.keys).where(conditions)</tt>.
     # Note that unlike reorder, we're only unscoping the named conditions -- not the entire where statement.
     def rewhere(conditions)
+      return unscope(:where) if conditions.nil?
+
       scope = spawn
       where_clause = scope.build_where_clause(conditions)
 

activerecord/test/cases/relation/where_chain_test.rb

@@ -183,5 +183,12 @@ def test_rewhere_with_infinite_range
 
       assert_equal expected.to_a, relation.to_a
     end
+
+    def test_rewhere_with_nil
+      relation = Post.where(comments_count: 16).rewhere(nil)
+      expected = Post.all
+
+      assert_equal expected.to_a, relation.to_a
+    end
   end
 end