mtest: Check that stdout is not None before seeking
As can be the case if additional_error is None and verbose is used.
Fixes
@@ -371,6 +371,10 @@ class SingleTestRunner:
endtime = time.time()
duration = endtime - starttime
if additional_error is None:
+ if stdout is None: # if stdout is None stderr should be as well
+ stdo = ''
+ stde = ''
+ else:
stdout.seek(0)
stdo = decode(stdout.read())
if stderr != stdout:
