From 342f582c2176776eed1b3be3fac0d4ac20020189 Mon Sep 17 00:00:00 2001
From: Will White <will@developmentseed.org>
Date: Thu, 16 Aug 2012 09:29:32 -0400
Subject: [PATCH] Be less strict when reading metadata.

If the metadata table or the requested field is
missing return null and allow the caller handle it.
---
 lib/mbtiles.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/mbtiles.js b/lib/mbtiles.js
index 220ec1e..8c81335 100644
--- a/lib/mbtiles.js
+++ b/lib/mbtiles.js
@@ -247,7 +247,9 @@ MBTiles.prototype._metadata = function(key, callback) {
     this._db.get('SELECT value FROM metadata WHERE name = ?',
         key,
         function(err, row) {
-            if (!row || (err && err.errno == 1)) return callback(new Error('Key does not exist'));
+            // If the metadata table or the requested field is missing return
+            // null and allow the caller handle it.
+            if (!row || (err && err.errno == 1)) return callback(null, null);
             else if (err) return callback(err);
             else return callback(null, row.value);
         });