From c6d3b8ad214db83868e55f8847d009f278bc7248 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Krist=C3=B3f=20T=C3=B3th?= <kristof.toth@avatao.com>
Date: Thu, 19 Jul 2018 11:31:31 +0200
Subject: [PATCH] Ensure _last_valid_branch consistency

---
 lib/tfw/components/snapshot_provider.py | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/lib/tfw/components/snapshot_provider.py b/lib/tfw/components/snapshot_provider.py
index e051238..e0a90ad 100644
--- a/lib/tfw/components/snapshot_provider.py
+++ b/lib/tfw/components/snapshot_provider.py
@@ -53,10 +53,10 @@ class SnapshotProvider:
     def _checkout_new_branch_from_head(self):
         head_hash = self._get_head_hash()
         self._run((
-            'git', 'checkout',
-            '-b', head_hash,
+            'git', 'branch',
             head_hash
         ))
+        self._checkout(head_hash)
 
     def _get_head_hash(self):
         return self._get_stdout((
@@ -68,6 +68,13 @@ class SnapshotProvider:
         commit = self._get_commit_from_timestamp(date)
         self._checkout(commit)
 
+    def _checkout(self, what):
+        self._run((
+            'git', 'checkout',
+            what
+        ))
+        self._update_last_valid_branch()
+
     def _get_commit_from_timestamp(self, date):
         return self._get_stdout((
             'git', 'rev-list',
@@ -77,12 +84,6 @@ class SnapshotProvider:
             self._last_valid_branch
         ))
 
-    def _checkout(self, what):
-        self._run((
-            'git', 'checkout',
-            what
-        ))
-
     def _get_stdout(self, *args, **kwargs):
         kwargs['capture_output'] = True
         stdout_bytes = self._run(*args, **kwargs).stdout
@@ -117,11 +118,13 @@ class SnapshotProvider:
 
     @property
     def _last_valid_branch(self):
-        current_branch = self._branch
-        if current_branch != 'HEAD':
-            self.__last_valid_branch = current_branch
+        self._update_last_valid_branch()
         return self.__last_valid_branch
 
+    def _update_last_valid_branch(self):
+        if not self._head_detached:
+            self.__last_valid_branch = self._branch
+
     @property
     def _head_detached(self):
         return self._branch == 'HEAD'