From 318e8eb3f2095205c8033e4c65fe6fedaf0822af Mon Sep 17 00:00:00 2001
From: Ryan <25047695+Ryanf55@users.noreply.github.com>
Date: Wed, 27 Nov 2024 19:37:09 -0700
Subject: [PATCH] Fix UB in SpiralIterator::operator++ (#481)

* Calling pop_back on an iterator past the end is UB

Signed-off-by: Ryan Friedman <25047695+Ryanf55@users.noreply.github.com>
(cherry picked from commit 74dbbc83ad695c09bc60dcc856aa8a75741311a9)
---
 grid_map_core/src/iterators/SpiralIterator.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/grid_map_core/src/iterators/SpiralIterator.cpp b/grid_map_core/src/iterators/SpiralIterator.cpp
index 6e094eb9a..168fb8564 100644
--- a/grid_map_core/src/iterators/SpiralIterator.cpp
+++ b/grid_map_core/src/iterators/SpiralIterator.cpp
@@ -66,6 +66,9 @@ const Eigen::Array2i & SpiralIterator::operator*() const
 
 SpiralIterator & SpiralIterator::operator++()
 {
+  if (isPastEnd()) {
+    return *this;
+  }
   pointsRing_.pop_back();
   if (pointsRing_.empty() && !isPastEnd()) {generateRing();}
   return *this;