From 1cae0e85b3bdb7773b54052c9b7fe0896b84f75b Mon Sep 17 00:00:00 2001
From: Eric Fischer <enf@pobox.com>
Date: Tue, 21 Oct 2014 16:16:09 -0700
Subject: [PATCH] Reindex features by their first coordinates so they coalesce
 better

---
 tile.cc | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tile.cc b/tile.cc
index 4efc57f..84a130d 100644
--- a/tile.cc
+++ b/tile.cc
@@ -992,7 +992,11 @@ long long write_tile(struct index *start, struct index *end, char *metabase, uns
 				struct coalesce c;
 
 				c.type = t;
-				c.index = i->index;
+				if (geom.size() > 0) {
+					c.index = encode(geom[0].x, geom[0].y);
+				} else {
+					c.index = i->index;
+				}
 				c.geom = geom;
 				c.metasrc = meta;
 				c.coalesced = false;