From 9ab4b2213a5a8ac466a9ddc3d7cf864299dab812 Mon Sep 17 00:00:00 2001
From: Themaister <maister@archlinux.us>
Date: Tue, 7 Jan 2014 17:43:44 +0100
Subject: [PATCH] Avoid potential overflows with overlay analogs.

---
 retroarch.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/retroarch.c b/retroarch.c
index 93b06e2af2..5c0d92b973 100644
--- a/retroarch.c
+++ b/retroarch.c
@@ -636,7 +636,15 @@ static int16_t input_state(unsigned port, unsigned device, unsigned index, unsig
    {
       unsigned base = (index == RETRO_DEVICE_INDEX_ANALOG_RIGHT) ? 2 : 0;
       base += (id == RETRO_DEVICE_ID_ANALOG_Y) ? 1 : 0;
-      res += driver.overlay_state.analog[base];
+
+      // Simply adding here could overflow the int16_t.
+      int sum = res + driver.overlay_state.analog[base];
+      if (sum > 0x7fff)
+         res = 0x7fff;
+      else if (sum < -0x7fff)
+         res = -0x7fff;
+      else
+         res = sum;
    }
 #endif