remain enabled and line specified trace points

If two or more tracepoints enabled with the same target and with
different target lines, the only last line is activated.
This patch fixes this issue by remaining existing trace instructions.
[Bug #17302]

1 files changed, 25 insertions, 0 deletions

diff --git a/test/ruby/test_settracefunc.rb b/test/ruby/test_settracefunc.rb
index 9579974407..2caf71c000 100644
--- a/test/ruby/test_settracefunc.rb
+++ b/test/ruby/test_settracefunc.rb
@@ -2175,6 +2175,31 @@ class TestSetTraceFunc < Test::Unit::TestCase
     assert_equal 'target_line is specified, but line event is not specified', e.message
   end
 
+  def test_tracepoint_enable_with_target_line_two_times
+    events = []
+    line_0 = __LINE__
+    code1 = proc{
+      events << 1 # tp1
+      events << 2
+      events << 3 # tp2
+    }
+
+    tp1 = TracePoint.new(:line) do |tp|
+      events << :tp1
+    end
+    tp2 = TracePoint.new(:line) do |tp|
+      events << :tp2
+    end
+
+    tp1.enable(target: code1, target_line: line_0 + 2) do
+      tp2.enable(target: code1, target_line: line_0 + 4) do
+        # two hooks
+        code1.call
+      end
+    end
+    assert_equal [:tp1, 1, 2, :tp2, 3], events
+  end
+
   def test_script_compiled
     events = []
     tp = TracePoint.new(:script_compiled){|tp|