From 00d878c62a7ab728f776306aa4d87843ac091104 Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Sat, 4 Jan 2014 14:34:49 -0800
Subject: [PATCH] Fixing arena chunk reuse.

---
 src/alloy/arena.cc           | 3 ++-
 src/alloy/hir/hir_builder.cc | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/alloy/arena.cc b/src/alloy/arena.cc
index 1649771dd..fe08f8c31 100644
--- a/src/alloy/arena.cc
+++ b/src/alloy/arena.cc
@@ -45,13 +45,14 @@ void Arena::DebugFill() {
 
 void* Arena::Alloc(size_t size) {
   if (active_chunk_) {
-    if (active_chunk_->capacity - active_chunk_->offset < size) {
+    if (active_chunk_->capacity - active_chunk_->offset < size + 4096) {
       Chunk* next = active_chunk_->next;
       if (!next) {
         XEASSERT(size < chunk_size_); // need to support larger chunks
         next = new Chunk(chunk_size_);
         active_chunk_->next = next;
       }
+      next->offset = 0;
       active_chunk_ = next;
     }
   } else {
diff --git a/src/alloy/hir/hir_builder.cc b/src/alloy/hir/hir_builder.cc
index c147ae0fc..43fa9e116 100644
--- a/src/alloy/hir/hir_builder.cc
+++ b/src/alloy/hir/hir_builder.cc
@@ -72,6 +72,7 @@ int HIRBuilder::Finalize() {
         // Sometimes VC++ generates functions with bl at the end even if they
         // will never return. Just add a return to satisfy things.
         XELOGW("Fall-through out of the function.");
+        Trap();
         Return();
         current_block_ = NULL;
         break;