rb_enc_interned_str: handle autoloaded encodings

If called with an autoloaded encoding that was not yet
initialized, `rb_enc_interned_str` would crash with
a NULL pointer exception.

See: https://github.com/ruby/ruby/pull/4119#issuecomment-800189841

1 files changed, 4 insertions, 0 deletions

diff --git a/string.c b/string.c
index 7605c225b9..90f6bca34f 100644
--- a/string.c
+++ b/string.c
@@ -11498,6 +11498,10 @@ rb_interned_str_cstr(const char *ptr)
 VALUE
 rb_enc_interned_str(const char *ptr, long len, rb_encoding *enc)
 {
+    if (UNLIKELY(rb_enc_autoload_p(enc))) {
+        rb_enc_autoload(enc);
+    }
+
     struct RString fake_str;
     return register_fstring(rb_setup_fake_str(&fake_str, ptr, len, enc), TRUE);
 }