Add FrozenError#receiver

Similar to NameError#receiver, this returns the object on which
the modification was attempted.  This is useful as it can pinpoint
exactly what is frozen.  In many cases when a FrozenError is
raised, you cannot determine from the context which object is
frozen that you attempted to modify.

Users of the current rb_error_frozen C function will have to switch
to using rb_error_frozen_object or the new rb_frozen_error_raise
in order to set the receiver of the FrozenError.

To allow the receiver to be set from Ruby, support an optional
second argument to FrozenError#initialize.

Implements [Feature #15751]

1 files changed, 2 insertions, 2 deletions

diff --git a/thread.c b/thread.c
index e88ed87306..d4f33a2e42 100644
--- a/thread.c
+++ b/thread.c
@@ -3325,7 +3325,7 @@ VALUE
 rb_thread_local_aset(VALUE thread, ID id, VALUE val)
 {
     if (OBJ_FROZEN(thread)) {
-	rb_error_frozen("thread locals");
+	rb_frozen_error_raise(thread, "can't modify frozen thread locals");
     }
 
     return threadptr_local_aset(rb_thread_ptr(thread), id, val);
@@ -3402,7 +3402,7 @@ rb_thread_variable_set(VALUE thread, VALUE id, VALUE val)
     VALUE locals;
 
     if (OBJ_FROZEN(thread)) {
-	rb_error_frozen("thread locals");
+	rb_frozen_error_raise(thread, "can't modify frozen thread locals");
     }
 
     locals = rb_ivar_get(thread, id_locals);