Allow prereleases to start with dots in loose mode

Fix #164

Author: isaacs

semver.js

@@ -80,7 +80,7 @@ src[PRERELEASE] = '(?:-(' + src[PRERELEASEIDENTIFIER] +
                   '(?:\\.' + src[PRERELEASEIDENTIFIER] + ')*))';
 
 var PRERELEASELOOSE = R++;
-src[PRERELEASELOOSE] = '(?:-?(' + src[PRERELEASEIDENTIFIERLOOSE] +
+src[PRERELEASELOOSE] = '(?:[-\.]?(' + src[PRERELEASEIDENTIFIERLOOSE] +
                        '(?:\\.' + src[PRERELEASEIDENTIFIERLOOSE] + ')*))';
 
 // ## Build Metadata Identifier

test/index.js

@@ -647,7 +647,9 @@ test('\nstrict vs loose version numbers', function(t) {
     ['01.02.03', '1.2.3'],
     ['1.2.3-beta.01', '1.2.3-beta.1'],
     ['   =1.2.3', '1.2.3'],
-    ['1.2.3foo', '1.2.3-foo']
+    ['1.2.3foo', '1.2.3-foo'],
+    ['1.2.3.foo', '1.2.3-foo'],
+    ['1.2.3.4.5.6.7.8.9.0', '1.2.3-4.5.6.7.8.9.0']
   ].forEach(function(v) {
     var loose = v[0];
     var strict = v[1];