From c5170290f8e222baeadaa4cec6279e3b5a9b1520 Mon Sep 17 00:00:00 2001
From: artemp <artem@mapnik.org>
Date: Tue, 16 Apr 2013 17:30:17 +0100
Subject: [PATCH] + image_reader : consistent error handling - throw
 image_reader_exception rather than returning 0 pointer.

---
 src/image_reader.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/image_reader.cpp b/src/image_reader.cpp
index 1ae83b42a..afa572b5d 100644
--- a/src/image_reader.cpp
+++ b/src/image_reader.cpp
@@ -68,7 +68,8 @@ image_reader* get_image_reader(char const* data, size_t size)
     boost::optional<std::string> type = type_from_bytes(data,size);
     if (type)
         return factory<image_reader,std::string,char const*,size_t>::instance().create_object(*type, data,size);
-    return 0;
+    else
+        throw image_reader_exception("image_reader: can't determine type from input data");
 }
 
 image_reader* get_image_reader(std::string const& filename,std::string const& type)