From 2d4c092de755752ecaf1d4b1240bab5a725049f2 Mon Sep 17 00:00:00 2001 From: "Yukihiro \"Matz\" Matsumoto" Date: Wed, 2 May 2018 22:50:55 +0900 Subject: Need to call `mrb_str_modify()` in `mrb_str_cat_str()`; fix #4018 If `str` and `str2` are the same string object `str->ptr` may be rewritten by `mrb_str_modify()`. --- src/string.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src') diff --git a/src/string.c b/src/string.c index e4bfd034c..5cca6d460 100644 --- a/src/string.c +++ b/src/string.c @@ -2615,6 +2615,9 @@ mrb_str_cat_cstr(mrb_state *mrb, mrb_value str, const char *ptr) MRB_API mrb_value mrb_str_cat_str(mrb_state *mrb, mrb_value str, mrb_value str2) { + if (mrb_str_ptr(str) == mrb_str_ptr(str2)) { + mrb_str_modify(mrb, mrb_str_ptr(str)); + } return mrb_str_cat(mrb, str, RSTRING_PTR(str2), RSTRING_LEN(str2)); } -- cgit v1.2.3