From e383be0149d025fa9966a7d2560a2d7eea72b8b4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Krist=C3=B3f=20T=C3=B3th?= <kristof.toth@avatao.com>
Date: Fri, 3 Aug 2018 11:55:51 +0200
Subject: [PATCH] Fix restore_snapshot() choking on timestamps before initial
 commit

---
 lib/tfw/components/snapshot_provider.py | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/tfw/components/snapshot_provider.py b/lib/tfw/components/snapshot_provider.py
index f0cd6ba..2c8dcee 100644
--- a/lib/tfw/components/snapshot_provider.py
+++ b/lib/tfw/components/snapshot_provider.py
@@ -129,13 +129,24 @@ class SnapshotProvider:
         self._checkout(commit)
 
     def _get_commit_from_timestamp(self, date):
-        return self._get_stdout((
+        commit = self._get_stdout((
             'git', 'rev-list',
             '--date=iso',
             '-n', '1',
             f'--before="{date.isoformat()}"',
             self._last_valid_branch
         ))
+        if not commit:
+            commit = self._get_oldest_parent_of_head()
+        return commit
+
+    def _get_oldest_parent_of_head(self):
+        return self._get_stdout((
+            'git',
+            'rev-list',
+            '--max-parents=0',
+            'HEAD'
+        ))
 
     @property
     def _last_valid_branch(self):