bitbake: tinfoil: Ensure we clean up loggers

This is primarily paranoid but ensure we remove any loggers we setup
either directly or indirectly so the initial state is restored after
we exit.

(Bitbake rev: af7d63b1f76fd3f7fa92ed15ae61ca47d9e13472)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/tinfoil.py

@@ -322,14 +322,14 @@ class Tinfoil:
         self.server_connection = None
         self.recipes_parsed = False
         self.quiet = 0
+        self.oldhandlers = self.logger.handlers[:]
         if setup_logging:
             # This is the *client-side* logger, nothing to do with
             # logging messages from the server
-            oldhandlers = self.logger.handlers[:]
             bb.msg.logger_create('BitBake', output)
             self.localhandlers = []
             for handler in self.logger.handlers:
-                if handler not in oldhandlers:
+                if handler not in self.oldhandlers:
                     self.localhandlers.append(handler)
 
     def __enter__(self):
@@ -835,6 +835,12 @@ class Tinfoil:
             self.server_connection.terminate()
             self.server_connection = None
 
+        # Restore logging handlers to how it looked when we started
+        if self.oldhandlers:
+            for handler in self.logger.handlers:
+                if handler not in self.oldhandlers:
+                    self.logger.handlers.remove(handler)
+
     def _reconvert_type(self, obj, origtypename):
         """
         Convert an object back to the right type, in the case