Fix a consistency bug of ISEQ_COVERAGE [Bug #13305]

There is an invariant that ISEQ_COVERAGE(iseq) must be Qnil if and only
if option->coverage_enabled is false.  This invariant was broken by
NODE_PRELUDE which updates option->coverage_enabled but not
ISEQ_COVERAGE(iseq).

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57971 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 34 insertions, 1 deletions

diff --git a/compile.c b/compile.c
index f6d8964fbb..7bfca53055 100644
--- a/compile.c
+++ b/compile.c
@@ -6310,14 +6310,17 @@ iseq_compile_each0(rb_iseq_t *iseq, LINK_ANCHOR *const ret, NODE *node, int popp
       }
       case NODE_PRELUDE:{
 	const rb_compile_option_t *orig_opt = ISEQ_COMPILE_DATA(iseq)->option;
+	VALUE orig_cov = ISEQ_COVERAGE(iseq);
+	rb_compile_option_t new_opt = *orig_opt;
 	if (node->nd_orig) {
-	    rb_compile_option_t new_opt = *orig_opt;
 	    rb_iseq_make_compile_option(&new_opt, node->nd_orig);
 	    ISEQ_COMPILE_DATA(iseq)->option = &new_opt;
 	}
+	if (!new_opt.coverage_enabled) ISEQ_COVERAGE_SET(iseq, Qfalse);
 	CHECK(COMPILE_POPPED(ret, "prelude", node->nd_head));
 	CHECK(COMPILE_(ret, "body", node->nd_body, popped));
 	ISEQ_COMPILE_DATA(iseq)->option = orig_opt;
+	ISEQ_COVERAGE_SET(iseq, orig_cov);
 	break;
       }
       case NODE_LAMBDA:{
diff --git a/test/coverage/test_coverage.rb b/test/coverage/test_coverage.rb
index 0753ccddc5..0fa8f9bd63 100644
--- a/test/coverage/test_coverage.rb
+++ b/test/coverage/test_coverage.rb
@@ -119,4 +119,34 @@ class TestCoverage < Test::Unit::TestCase
     end
     assert_include Coverage.result, "<compiled>"
   end
+
+  def test_eval
+    bug13305 = '[ruby-core:80079] [Bug #13305]'
+    loaded_features = $".dup
+
+    Dir.mktmpdir {|tmp|
+      Dir.chdir(tmp) {
+        File.open("test.rb", "w") do |f|
+          f.puts 'REPEATS = 400'
+          f.puts 'def add_method(target)'
+          f.puts '  REPEATS.times do'
+          f.puts '    target.class_eval(<<~RUBY, __FILE__, __LINE__ + 1)'
+          f.puts '      def foo'
+          f.puts '        #{"\n" * rand(REPEATS)}'
+          f.puts '      end'
+          f.puts '      1'
+          f.puts '    RUBY'
+          f.puts '  end'
+          f.puts 'end'
+        end
+
+        Coverage.start
+        require tmp + '/test.rb'
+        add_method(Class.new)
+        assert_equal Coverage.result[tmp + "/test.rb"], [1, 1, 1, 400, nil, nil, nil, nil, nil, nil, nil], bug13305
+      }
+    }
+  ensure
+    $".replace loaded_features
+  end
 end unless ENV['COVERAGE']