merge revision(s) df317151a5: [Backport #16019]

should not free local hook_list here.

	exec_hooks_postcheck() clean executed hook_list if it is needed.
	list_exec is freed if there are no events and this list is local
	event (connected to specific iseq). However, iseq keeps to point
	this local hook_list, freed list. To prevent this situation,
	do not free hook_list here even if it has no events.

	This issue is reported by @joker1007.
	https://twitter.com/joker1007/status/1153649170797830144

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_6@67744 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_settracefunc.rb

@@ -2127,4 +2127,21 @@ class TestSetTraceFunc < Test::Unit::TestCase
     tp.enable {obj.example}
     assert ok, "return event should be emitted"
   end
+
+  def test_disable_local_tracepoint_in_trace
+    assert_normal_exit <<-EOS
+    def foo
+      trace = TracePoint.new(:b_return){|tp|
+        tp.disable
+      }
+      trace.enable(target: method(:bar))
+    end
+    def bar
+      100.times{|i|
+        foo; foo
+      }
+    end
+    bar
+    EOS
+  end
 end

version.h

@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.6.3"
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 94
+#define RUBY_PATCHLEVEL 95
 
 #define RUBY_RELEASE_YEAR 2019
 #define RUBY_RELEASE_MONTH 8

vm_trace.c

@@ -198,9 +198,6 @@ clean_hooks(const rb_execution_context_t *ec, rb_hook_list_t *list)
     }
     else {
         /* local events */
-        if (list->events == 0) {
-            ruby_xfree(list);
-        }
     }
 }