From a408b0732eee32cbc9e508b0593e83d7b075128d Mon Sep 17 00:00:00 2001
From: Artem Pavlenko <artem@mapnik.org>
Date: Tue, 7 Nov 2017 14:32:33 +0100
Subject: [PATCH] Don't collect invalid bounding boxes (ref #3709)

---
 .../mapnik/json/extract_bounding_box_grammar_impl.hpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/include/mapnik/json/extract_bounding_box_grammar_impl.hpp b/include/mapnik/json/extract_bounding_box_grammar_impl.hpp
index 4d81de766..b3ac07ec2 100644
--- a/include/mapnik/json/extract_bounding_box_grammar_impl.hpp
+++ b/include/mapnik/json/extract_bounding_box_grammar_impl.hpp
@@ -61,10 +61,13 @@ struct push_box_impl
     template <typename T0, typename T1, typename T2, typename T3>
     void operator() (T0 & boxes, T1 const& begin, T2 const& box, T3 const& range) const
     {
-        boxes.emplace_back(box,
-                           std::make_pair(std::distance(begin,
-                                                        range.begin()),
-                                          std::distance(range.begin(), range.end())));
+        if (box.valid())
+        {
+            boxes.emplace_back(box,
+                               std::make_pair(std::distance(begin,
+                                                            range.begin()),
+                                              std::distance(range.begin(), range.end())));
+        }
     }
 };