From e412b7e10fd5308ceaf67cdc2b4058a724d178e5 Mon Sep 17 00:00:00 2001
From: Nicky <none@none>
Date: Mon, 18 Feb 2013 23:11:03 +0100
Subject: [PATCH] FIRE-9251; make sure there's no iterator used out of the maps
 valid range.

---
 indra/llprimitive/llmodel.cpp | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/indra/llprimitive/llmodel.cpp b/indra/llprimitive/llmodel.cpp
index 5e119f086b..62cfecab52 100644
--- a/indra/llprimitive/llmodel.cpp
+++ b/indra/llprimitive/llmodel.cpp
@@ -1735,9 +1735,22 @@ LLModel::weight_list& LLModel::getJointInfluences(const LLVector3& pos)
 		weight_map::iterator iter_up = mSkinWeights.lower_bound(pos);
 		weight_map::iterator iter_down = ++iter_up;
 
+		// <FS:ND> FIRE-9251; it can happen than iter_up points at end(), in that case iter_down points to end()+1. Adjust iter_up to end()-1 and iter_down to end then.
+		// This will gurantee we have at least one valid pointer from our map and can use that safely as 'best'.
+		if( mSkinWeights.end() == iter_up )
+		{
+			iter_down = iter_up;
+			--iter_up;
+		}
+		// </FS:ND>
+
+
 		weight_map::iterator best = iter_up;
 
-		F32 min_dist = (iter->first - pos).magVec();
+		// <FS:ND> FIRE-9251; There is no way iter can be valid here, otherwise we had hit the if branch and not the else branch.
+		// F32 min_dist = (iter->first - pos).magVec();
+		F32 min_dist = (best->first - pos).magVec();
+		// </FS:ND>
 
 		bool done = false;
 		while (!done)