From 466c644380a3ac67c4a05d8fc3e46a6dfb0491f6 Mon Sep 17 00:00:00 2001
From: Alex Kocharin <alex@kocharin.ru>
Date: Thu, 6 Sep 2012 01:34:38 +0400
Subject: [PATCH 1/2] restore original timezone in case of error

---
 index.js     | 8 +++++++-
 test/date.js | 7 +++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index d9f237d..3eb71bb 100644
--- a/index.js
+++ b/index.js
@@ -249,7 +249,13 @@ function setTimezone (timezone, relative) {
     , tz = exports._currentZoneinfo;
   if (!tz || oldTz !== timezone) {
     debug('current timezone is not "%s", calling tzset()', timezone);
-    tz = exports.tzset(timezone);
+    try {
+       tz = exports.tzset(timezone);
+    } catch(err) {
+       // If there was a invalid timezone, restore it back and rethrow
+       exports.tzset(oldTz);
+       throw err;
+    }
   }
 
   // Get the zoneinfo for this Date instance's time value
diff --git a/test/date.js b/test/date.js
index 92be017..585d187 100644
--- a/test/date.js
+++ b/test/date.js
@@ -51,6 +51,13 @@ describe('Date', function () {
       initial.should.equal(process.env.TZ)
     })
 
+    it('should clean up after an error', function () {
+      var initial = process.env.TZ
+        , d = new time.Date
+      d.setTimezone.bind(d, 'Any/Wrong/TZ').should.throw(/^Unknown Timezone/)
+      initial.should.equal(process.env.TZ)
+    })
+
     it('should change the "timezone offset"', function () {
       var d = new time.Date
         , offset = d.getTimezoneOffset()

From c83d41b2bfe604c3ce625b67d8b10fff61ab9e71 Mon Sep 17 00:00:00 2001
From: Alex Kocharin <alex@kocharin.ru>
Date: Thu, 6 Sep 2012 02:05:06 +0400
Subject: [PATCH 2/2] tzset() should probably restore TZ too, so moved this
 code deeper

---
 index.js | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/index.js b/index.js
index 3eb71bb..9061056 100644
--- a/index.js
+++ b/index.js
@@ -147,6 +147,10 @@ function tzset (tz) {
   debug('set the current timezone to:', usedTz);
   if (!rtn.tzname[1] && rtn.timezone === 0) {
     debug('got bad zoneinfo object:', rtn);
+    if (tz !== exports.currentTimezone) {
+      // restore original timezone in case of error
+      tzset(exports.currentTimezone);
+    }
     var err = new Error("Unknown Timezone: '" + usedTz + "'");
     for (var i in rtn) {
       err[i] = rtn[i];
@@ -249,13 +253,7 @@ function setTimezone (timezone, relative) {
     , tz = exports._currentZoneinfo;
   if (!tz || oldTz !== timezone) {
     debug('current timezone is not "%s", calling tzset()', timezone);
-    try {
-       tz = exports.tzset(timezone);
-    } catch(err) {
-       // If there was a invalid timezone, restore it back and rethrow
-       exports.tzset(oldTz);
-       throw err;
-    }
+    tz = exports.tzset(timezone);
   }
 
   // Get the zoneinfo for this Date instance's time value