1 files changed, 38 insertions, 0 deletions
diff --git a/ext/-test-/string/fstring.c b/ext/-test-/string/fstring.c
new file mode 100644
index 0000000000..0b5940f28c
--- /dev/null
+++ b/ext/-test-/string/fstring.c
@@ -0,0 +1,38 @@
+#include "ruby.h"
+#include "ruby/encoding.h"
+#include "internal/string.h"
+
+VALUE
+bug_s_fstring(VALUE self, VALUE str)
+{
+    return rb_str_to_interned_str(str);
+}
+
+VALUE
+bug_s_fstring_fake_str(VALUE self)
+{
+    static const char literal[] = "abcdefghijklmnopqrstuvwxyz";
+    struct RString fake_str = {RBASIC_INIT};
+    return rb_str_to_interned_str(rb_setup_fake_str(&fake_str, literal, sizeof(literal) - 1, 0));
+}
+
+VALUE
+bug_s_rb_enc_interned_str(VALUE self, VALUE encoding)
+{
+    return rb_enc_interned_str("foo", 3, NIL_P(encoding) ? NULL : RTYPEDDATA_GET_DATA(encoding));
+}
+
+VALUE
+bug_s_rb_enc_str_new(VALUE self, VALUE encoding)
+{
+    return rb_enc_str_new("foo", 3, NIL_P(encoding) ? NULL : RTYPEDDATA_GET_DATA(encoding));
+}
+
+void
+Init_string_fstring(VALUE klass)
+{
+    rb_define_singleton_method(klass, "fstring", bug_s_fstring, 1);
+    rb_define_singleton_method(klass, "fstring_fake_str", bug_s_fstring_fake_str, 0);
+    rb_define_singleton_method(klass, "rb_enc_interned_str", bug_s_rb_enc_interned_str, 1);
+    rb_define_singleton_method(klass, "rb_enc_str_new", bug_s_rb_enc_str_new, 1);
+}