string.c (rb_str_tmp_frozen_release): release embedded strings

Handle the embedded case first, since we may have an embedded
duplicate and non-embedded original string.

* string.c (rb_str_tmp_frozen_release): handled embedded strings
* test/ruby/test_io.rb (test_write_no_garbage): new test
  [ruby-core:78898] [Bug #13085]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57471 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

string.c

@@ -1150,7 +1150,11 @@ rb_str_tmp_frozen_release(VALUE orig, VALUE tmp)
     if (RBASIC_CLASS(tmp) != 0)
 	return;
 
-    if (FL_TEST_RAW(orig, STR_SHARED) &&
+    if (STR_EMBED_P(tmp)) {
+	assert(OBJ_FROZEN_RAW(tmp));
+	rb_gc_force_recycle(tmp);
+    }
+    else if (FL_TEST_RAW(orig, STR_SHARED) &&
 	    !FL_TEST_RAW(orig, STR_TMPLOCK|RUBY_FL_FREEZE)) {
 	VALUE shared = RSTRING(orig)->as.heap.aux.shared;
 
@@ -1164,10 +1168,6 @@ rb_str_tmp_frozen_release(VALUE orig, VALUE tmp)
 	    rb_gc_force_recycle(tmp);
 	}
     }
-    else if (STR_EMBED_P(tmp)) {
-	assert(OBJ_FROZEN_RAW(tmp));
-	rb_gc_force_recycle(tmp);
-    }
 }
 
 static VALUE

test/ruby/test_io.rb

@@ -3504,5 +3504,21 @@ __END__
         end
       end
     end
+
+    def test_write_no_garbage
+      res = {}
+      ObjectSpace.count_objects(res) # creates strings on first call
+      [ 'foo'.b, '*' * 24 ].each do |buf|
+        with_pipe do |r, w|
+          before = ObjectSpace.count_objects(res)[:T_STRING]
+          n = w.write(buf)
+          after = ObjectSpace.count_objects(res)[:T_STRING]
+          assert_equal before, after,
+            'no strings left over after write [ruby-core:78898] [Bug #13085]'
+          assert_not_predicate buf, :frozen?, 'no inadvertant freeze'
+          assert_equal buf.bytesize, n, 'wrote expected size'
+        end
+      end
+    end
   end
 end