From cf2df4f0cc719cbb113b265f58c8fecc27832108 Mon Sep 17 00:00:00 2001
From: Dane Springmeyer <dane@mapbox.com>
Date: Sun, 12 Oct 2014 15:48:15 -0700
Subject: [PATCH] harfbuzz shaper: return early if itemizer returns empty list

---
 include/mapnik/text/harfbuzz_shaper.hpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/mapnik/text/harfbuzz_shaper.hpp b/include/mapnik/text/harfbuzz_shaper.hpp
index bb123b63d..c9016c8e7 100644
--- a/include/mapnik/text/harfbuzz_shaper.hpp
+++ b/include/mapnik/text/harfbuzz_shaper.hpp
@@ -68,8 +68,11 @@ static void shape_text(text_line & line,
     unsigned end = line.last_char();
     size_t length = end - start;
     if (!length) return;
-    line.reserve(length);
+
     std::list<text_item> const& list = itemizer.itemize(start, end);
+    if (list.empty()) return;
+
+    line.reserve(length);
 
     auto hb_buffer_deleter = [](hb_buffer_t * buffer) { hb_buffer_destroy(buffer);};
     const std::unique_ptr<hb_buffer_t, decltype(hb_buffer_deleter)> buffer(hb_buffer_create(),hb_buffer_deleter);