Add sanity checks for system clock changes.

1 files changed, 7 insertions, 1 deletions

diff --git a/pym/_emerge/PollScheduler.py b/pym/_emerge/PollScheduler.py
index 68826e28e..e71350e5b 100644
--- a/pym/_emerge/PollScheduler.py
+++ b/pym/_emerge/PollScheduler.py
@@ -235,7 +235,13 @@ class PollScheduler(object):
 					break
 				if timeout is not None:
 					elapsed_time = time.time() - start_time
-					remaining_timeout = (timeout - 1000 * elapsed_time)
+					if elapsed_time < 0:
+						# The system clock has changed such that start_time
+						# is now in the future, so just assume that the
+						# timeout has already elapsed.
+						timed_out = True
+						break
+					remaining_timeout = timeout - 1000 * elapsed_time
 					if remaining_timeout <= 0:
 						timed_out = True
 						break