bug#47535: 27.2; comint shell hangs on long input

[Andreas Schwab]

On Mär 31 2021, David Biesack via "Bug reports for GNU Emacs, the Swiss army 
knife of text editors" wrote:

> Start Emacs with emacs -Q
>
> M-x shell
>
> in the shell buffer, enter
>
> echo <C-u> 1 0 0 0 x <Return>
>
> to echo 1,000 x's. Works fine.
>
> echo <C-u> 1 0 2 4 x <Return>
>
> to echo 1,024 x's. The shell buffer prints the command, then "hangs" and
> the output is never printed, and the command prompt not issued. no
> character input works (Return, etc.)

That's a limitation of the BSD tty interface.  Once the input buffer is
full, no more characters can be sent, not even a newline or the EOF
character.  The Linux tty interface instead discards further input until
the newline or EOF.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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