pdb: DontReadFromInput vs EOFError

[blueyed]

DontReadFromInput only throws IOError when read is being used.

pyrepl for example would raise termios.error when it tries to use tcgetattr - it does not read directly:

INTERNALERROR> Traceback (most recent call last):
INTERNALERROR>   File "/home/daniel/Vcs/pyrepl-git/pyrepl/reader.py", line 482, in prepare
INTERNALERROR>     self.console.prepare()
INTERNALERROR>   File "/home/daniel/Vcs/pyrepl-git/pyrepl/unix_console.py", line 357, in prepare
INTERNALERROR>     self.__svtermstate = tcgetattr(self.input_fd)
INTERNALERROR>   File "/home/daniel/Vcs/pyrepl-git/pyrepl/fancy_termios.py", line 34, in tcgetattr
INTERNALERROR>     return TermState(termios.tcgetattr(fd))
INTERNALERROR> termios.error: (25, 'Inappropriate ioctl for device')

I've tried changing this to EOFError, which I found more appropriate (https://github.com/blueyed/pyrepl/pull/7), but then noticed that this causes pytest to consider this to be a quitting-the-debugger event (same as Ctrl-d).

This "silent" exit was confusing when I've noticed this while stepping to pytest itself, where it would run code with set_trace and apparently capturing output around it (another/a different issue).

I think we should maybe not use Exit for do_EOF (via set_quit), but only with do_quit as a first step. This would also give the benefit of having Ctrl-d work differently than q (displaying a traceback, and test summaries).

pytest/src/_pytest/capture.py

Lines 704 to 738 in 2051e30

	class DontReadFromInput(six.Iterator):
	"""Temporary stub class. Ideally when stdin is accessed, the
	capturing should be turned off, with possibly all data captured
	so far sent to the screen. This should be configurable, though,
	because in automated test runs it is better to crash than
	hang indefinitely.
	"""
	encoding = None
	def read(self, *args):
	raise IOError("reading from stdin while output is captured")
	readline = read
	readlines = read
	__next__ = read
	def __iter__(self):
	return self
	def fileno(self):
	raise UnsupportedOperation("redirected stdin is pseudofile, has no fileno()")
	def isatty(self):
	return False
	def close(self):
	pass
	@property
	def buffer(self):
	if sys.version_info >= (3, 0):
	return self
	else:
	raise AttributeError("redirected stdin has no attribute buffer")