io.c: check null char

* io.c (ruby_set_inplace_mode): check if null is contained.  based
  on the patch by tommy (Masahiro Tomita) in [ruby-dev:50272].
  [Bug #13960]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60097 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 2 deletions

diff --git a/io.c b/io.c
index 1254e92363..6226108ad6 100644
--- a/io.c
+++ b/io.c
@@ -12224,10 +12224,10 @@ argf_inplace_mode_set(VALUE argf, VALUE val)
 	ARGF.inplace = 0;
     }
     else {
-	StringValue(val);
+	const char *suffix = StringValueCStr(val);
 	if (ARGF.inplace) free(ARGF.inplace);
 	ARGF.inplace = 0;
-	ARGF.inplace = strdup(RSTRING_PTR(val));
+	ARGF.inplace = strdup(suffix);
     }
     return argf;
 }