From 06e2fbb8260022de8532d2e940fc69e8ea413679 Mon Sep 17 00:00:00 2001
From: Kouhei Yanagita <yanagi@shakenbu.org>
Date: Wed, 22 Nov 2023 18:12:23 +0900
Subject: [PATCH] [Bug #19114] Fix for multiple calls of TracePoint#enable

---
 test/ruby/test_settracefunc.rb | 12 ++++++++++++
 vm_trace.c                     |  4 ++++
 2 files changed, 16 insertions(+)

diff --git a/test/ruby/test_settracefunc.rb b/test/ruby/test_settracefunc.rb
index 8fcc909d83..b7711e191d 100644
--- a/test/ruby/test_settracefunc.rb
+++ b/test/ruby/test_settracefunc.rb
@@ -2459,6 +2459,18 @@ CODE
     assert_equal [:tp1, 1, 2, :tp2, 3], events
   end
 
+  def test_multiple_enable
+    ary = []
+    trace = TracePoint.new(:call) do |tp|
+      ary << tp.method_id
+    end
+    trace.enable
+    trace.enable
+    foo
+    trace.disable
+    assert_equal(1, ary.count(:foo), '[Bug #19114]')
+  end
+
   def test_multiple_tracepoints_same_bmethod
     events = []
     tp1 = TracePoint.new(:return) do |tp|
diff --git a/vm_trace.c b/vm_trace.c
index 4b97288f23..6969c8d3ce 100644
--- a/vm_trace.c
+++ b/vm_trace.c
@@ -1197,6 +1197,10 @@ rb_tracepoint_enable(VALUE tpval)
         rb_raise(rb_eArgError, "can't nest-enable a targeting TracePoint");
     }
 
+    if (tp->tracing) {
+        return Qundef;
+    }
+
     if (tp->target_th) {
         rb_thread_add_event_hook2(tp->target_th->self, (rb_event_hook_func_t)tp_call_trace, tp->events, tpval,
                                   RUBY_EVENT_HOOK_FLAG_SAFE | RUBY_EVENT_HOOK_FLAG_RAW_ARG);