Patch by Xavier de Gaye.

Patch by Xavier de Gaye.

The update_idletasks solution was provided by Serhiy Storchaka.

now correctly ignores BrokenPipeError when the child process dies
before .communicate() is called in more (all?) circumstances.

BrokenPipeError when the child process dies before .communicate()
is called in more (all?) circumstances.

Clarifies what is returned when and that the methods are common between the two.

Patch by Alexander Liu as part of #22797.

Patch by Sean Rodman, test by Kaushik N.