From d56a19cbf526190de036130fe3a5bf14a0705ee2 Mon Sep 17 00:00:00 2001
From: Bouke van der Bijl <boukevanderbijl@gmail.com>
Date: Fri, 2 Dec 2016 09:48:28 -0500
Subject: Don't generate code for NODE_NEGATE if the result isn't used

Reported by https://hackerone.com/haquaman
---
 mrbgems/mruby-compiler/core/codegen.c |  4 ++++
 test/t/codegen.rb                     | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/mrbgems/mruby-compiler/core/codegen.c b/mrbgems/mruby-compiler/core/codegen.c
index b2cd12225..891c4f62b 100644
--- a/mrbgems/mruby-compiler/core/codegen.c
+++ b/mrbgems/mruby-compiler/core/codegen.c
@@ -2223,6 +2223,10 @@ codegen(codegen_scope *s, node *tree, int val)
     {
       nt = (intptr_t)tree->car;
       tree = tree->cdr;
+      if (!val) {
+        codegen(s, tree, NOVAL);
+        break;
+      }
       switch (nt) {
       case NODE_FLOAT:
         {
diff --git a/test/t/codegen.rb b/test/t/codegen.rb
index bb0f5c306..bd360dbcb 100644
--- a/test/t/codegen.rb
+++ b/test/t/codegen.rb
@@ -63,3 +63,13 @@ assert('splat in case splat') do
 
   assert_equal [1], a
 end
+
+assert('negate literal register alignment') do
+  a = *case
+  when 0
+    -0.0
+    2
+  end
+
+  assert_equal [2], a
+end
-- 
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