fix handling of empty files

test/info.test.js

@@ -0,0 +1,70 @@
+process.env.NODE_ENV = 'test';
+
+var fs = require('fs');
+var Step = require('step');
+var assert = require('assert');
+var MBTiles = require('..');
+
+var fixtures = {
+    plain_1: __dirname + '/fixtures/plain_1.mbtiles',
+    empty: __dirname + '/fixtures/empty.mbtiles'
+};
+
+try { fs.unlink(fixtures.empty); } catch (err) {}
+
+
+exports['get metadata'] = function(beforeExit) {
+    var completed = false;
+
+    new MBTiles(fixtures.plain_1, function(err, mbtiles) {
+        if (err) throw err;
+
+        mbtiles.getInfo(function(err, data) {
+            completed = true;
+            if (err) throw err;
+
+            assert.deepEqual({
+                name: 'plain_1',
+                description: 'demo description',
+                version: '1.0.3',
+                scheme: 'tms',
+                minzoom: 0,
+                maxzoom: 4,
+                formatter: null,
+                center: [ 0, 7.500000001278025, 2 ],
+                bounds: [ -179.9999999749438, -69.99999999526695, 179.9999999749438, 84.99999999782301 ],
+
+                // These aren't part of TileJSON, but exist in an MBTiles file.
+                filesize: 561152,
+                type: 'baselayer',
+                id: 'plain_1',
+                basename: 'plain_1.mbtiles'
+            }, data);
+        })
+    });
+
+    beforeExit(function() {
+        assert.ok(completed);
+    });
+};
+
+exports['get/put metadata from empty file'] = function(beforeExit) {
+    var completed = false;
+
+    new MBTiles(fixtures.empty, function(err, mbtiles) {
+        if (err) throw err;
+
+        mbtiles.getInfo(function(err, data) {
+            completed = true;
+            if (err) throw err;
+
+            assert.deepEqual({
+                basename: "empty.mbtiles",
+                filesize: 16384,
+                id: "empty",
+                scheme: "tms"
+            }, data);
+        })
+    });
+};
+