Fix memory leak

* string.c (str_replace_shared_without_enc): free previous buffer
  before replaced.

* parse.y (gettable): make sure in advance that the `__FILE__`
  object shares a fstring, to get rid of replacement with the
  fstring later.
  TODO: this hack may be needed in other places.

[Bug #15916]

Co-Authored-By: luke-gru (Luke Gruber) <luke.gru@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/parse.y b/parse.y
index a7cdddcaec..d76d3b2562 100644
--- a/parse.y
+++ b/parse.y
@@ -9748,7 +9748,7 @@ gettable(struct parser_params *p, ID id, const YYLTYPE *loc)
 	    if (NIL_P(file))
 		file = rb_str_new(0, 0);
 	    else
-		file = rb_str_dup(file);
+		file = rb_str_dup(rb_fstring(file));
 	    node = NEW_STR(add_mark_object(p, file), loc);
 	}
 	return node;