fix peephole optimization.

* compile.c (iseq_peephole_optimize): do not need to put `pop`
  instruction.

* test/ruby/test_optimization.rb (test_peephole_optimization_without_trace):
  This code "def foo; 1.times{|(a), &b| nil && a}; end" fails to compile
  by stack underflow because of above bug (fixed by this patch).


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60724 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 7 insertions, 3 deletions

diff --git a/compile.c b/compile.c
index 76bc107abe..bcc7dce9fd 100644
--- a/compile.c
+++ b/compile.c
@@ -2324,13 +2324,10 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
 	     * LABEL:
 	     *  leave
 	     */
-	    INSN *popiobj = new_insn_core(iseq, iobj->line_no,
-					  BIN(pop), 0, 0);
 	    /* replace */
 	    unref_destination(iobj, 0);
 	    iobj->insn_id = BIN(leave);
 	    iobj->operand_size = 0;
-	    INSERT_ELEM_NEXT(&iobj->link, &popiobj->link);
 	    goto again;
 	}
 	else if ((piobj = (INSN *)get_prev_insn(iobj)) != 0 &&
diff --git a/test/ruby/test_optimization.rb b/test/ruby/test_optimization.rb
index ed16ad9fe2..40015c57dd 100644
--- a/test/ruby/test_optimization.rb
+++ b/test/ruby/test_optimization.rb
@@ -640,4 +640,11 @@ class TestRubyOptimization < Test::Unit::TestCase
       assert_equal 0, foo{$SAFE}
     END
   end
+
+  def test_peephole_optimization_without_trace
+    assert_separately [], <<-END
+      RubyVM::InstructionSequence.compile_option = {trace_instruction: false}
+      eval "def foo; 1.times{|(a), &b| nil && a}; end"
+    END
+  end
 end