From b2eff136675f1340abb794fcd7b016663d981547 Mon Sep 17 00:00:00 2001
From: Eric Fischer <enf@pobox.com>
Date: Fri, 19 Dec 2014 14:33:39 -0800
Subject: [PATCH] Impose a limit on the maximum number of features in a tile.

---
 tile.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tile.cc b/tile.cc
index d8fe408b1..99cb32361 100644
--- a/tile.cc
+++ b/tile.cc
@@ -569,6 +569,12 @@ long long write_tile(char **geoms, char *metabase, unsigned *file_bbox, int z, u
 		}
 
 		if (features.size() > 0) {
+			if (features.size() > 200000) {
+				fprintf(stderr, "tile %d/%u/%u has %lld features, >200000    \n", z, tx, ty, (long long) features.size());
+				fprintf(stderr, "Try using -z to set a higher base zoom level.\n");
+				exit(EXIT_FAILURE);
+			}
+
 			mapnik::vector::tile tile = create_tile(layername, line_detail, features, &count, &keys, &values);
 
 			pool_free(&keys);