Raise a TypeError for Thread#thread_variable{?,_get} for non-symbol

Previously, a TypeError was not raised if there were no thread
variables, because the conversion to symbol was done after that
check.  Convert to symbol before checking for whether thread
variables are set to make the behavior consistent.

Fixes [Bug #20606]

1 files changed, 4 insertions, 2 deletions

diff --git a/thread.c b/thread.c
index 56f1399d41..45aa0565ca 100644
--- a/thread.c
+++ b/thread.c
@@ -3756,12 +3756,13 @@ static VALUE
 rb_thread_variable_get(VALUE thread, VALUE key)
 {
     VALUE locals;
+    VALUE symbol = rb_to_symbol(key);
 
     if (LIKELY(!THREAD_LOCAL_STORAGE_INITIALISED_P(thread))) {
         return Qnil;
     }
     locals = rb_thread_local_storage(thread);
-    return rb_hash_aref(locals, rb_to_symbol(key));
+    return rb_hash_aref(locals, symbol);
 }
 
 /*
@@ -3912,13 +3913,14 @@ static VALUE
 rb_thread_variable_p(VALUE thread, VALUE key)
 {
     VALUE locals;
+    VALUE symbol = rb_to_symbol(key);
 
     if (LIKELY(!THREAD_LOCAL_STORAGE_INITIALISED_P(thread))) {
         return Qfalse;
     }
     locals = rb_thread_local_storage(thread);
 
-    return RBOOL(rb_hash_lookup(locals, rb_to_symbol(key)) != Qnil);
+    return RBOOL(rb_hash_lookup(locals, symbol) != Qnil);
 }
 
 /*