py3: tweak stdout writing in test-hgweb-no-path-info.t We want to write bytes for convenience. This requires sys.stdout.buffer. But using sys.stdout.buffer introducing buffered output. So we sprinkle code with sys.stdout.flush() to force immediate writes. After all that, Python 3 was emitting b'' prefixed output for errors. So we only print errors if there were some. There aren't, so b'' don't come into play and output is identical in Python 2 and 3. Differential Revision: https://phab.mercurial-scm.org/D4972