Merge pull request #823 from danshultz/string_chomp_passed_nil

string.chomp!(nil) returns nil

spec/tags/core/string/chomp_tags.txt

@@ -1,4 +1,2 @@
-fails:String#chomp! when passed nil returns nil
-fails:String#chomp! when passed nil returns nil when self is empty
 fails:String#chomp removes the final carriage return, newline from a non-ASCII String
 fails:String#chomp! removes the final carriage return, newline from a non-ASCII String

tests/objects/test_stringobject.py

@@ -440,6 +440,8 @@ def test_chomp(self, space):
         assert w_res is space.w_nil
         w_res = space.execute('return "".chomp!')
         assert w_res is space.w_nil
+        w_res = space.execute('return "abc".chomp!(nil)')
+        assert w_res is space.w_nil
         w_res = space.execute('return "abc\\r".chomp!("")')
         assert w_res is space.w_nil
 

topaz/objects/stringobject.py

@@ -1212,7 +1212,7 @@ def method_chomp_i(self, space, w_newline=None):
         if w_newline is None:
             w_newline = space.globals.get(space, "$/")
         if w_newline is space.w_nil:
-            return self
+            return space.w_nil
         newline = space.str_w(space.convert_type(w_newline, space.w_string, "to_str"))
         if newline and newline in "\n\r":
             newline = None