bug#61341: Tramp process truncate messages to 4096 bytes

bug#61341: Tramp process truncate messages to 4096 bytes

[Haiwei Zhou]

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Hi,

  According to this link
<https://stackoverflow.com/questions/18015137/linux-terminal-input-reading-user-input-from-terminal-truncating-lines-at-4095>,
Linux terminals truncated messages to 4096 bytes under the tty canonical
mode. To fix this issue, the following patch will help. I tested on emacs
28.2 with tramp 2.5.3.

--- tramp-sh.el.orig	2022-05-12 19:59:16.000000000 +0800
+++ tramp-sh.el	2023-01-28 11:14:40.371519390 +0800
@@ -2959,7 +2959,7 @@
 			  ;; macOS, see Bug#50748.
 			  (when (and (memq connection-type '(nil pipe))
                                      (not (tramp-check-remote-uname v
"Darwin")))
-			    (tramp-send-command v "stty -icrnl"))
+			    (tramp-send-command v "stty -icrnl -icanon"))
 			  ;; `tramp-maybe-open-connection' and
 			  ;; `tramp-send-command-and-read' could have
 			  ;; trashed the connection buffer.  Remove this.



Thanks,
Haiwei

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bug#61341: Tramp process truncate messages to 4096 bytes

[Michael Albinus]

Version: 29.2

Haiwei Zhou <highfly22@gmail.com> writes:

> Hi,

Hi,

>   According to this link, Linux terminals truncated messages to 4096
> bytes under the tty canonical mode. To fix this issue, the following
> patch will help. I tested on emacs 28.2 with tramp 2.5.3.
>
> --- tramp-sh.el.orig	2022-05-12 19:59:16.000000000 +0800
> +++ tramp-sh.el	2023-01-28 11:14:40.371519390 +0800
> @@ -2959,7 +2959,7 @@
>  			  ;; macOS, see Bug#50748.
>  			  (when (and (memq connection-type '(nil pipe))
>                                       (not (tramp-check-remote-uname v "Darwin")))
> -			    (tramp-send-command v "stty -icrnl"))
> +			    (tramp-send-command v "stty -icrnl -icanon"))
>  			  ;; `tramp-maybe-open-connection' and
>  			  ;; `tramp-send-command-and-read' could have
>  			  ;; trashed the connection buffer.  Remove this.

In general, your patch looks good. Since I don't use lsp-mode I cannot
check it there, but I trust you that it helps.

However, two enhancements must be done. First, it shall be applied for
remote macOS hosts as well. And secondly, when setting -icanon, one must
also set min and time.

Finally, I've changed this to

--8<---------------cut here---------------start------------->8---
			    (when (memq connection-type '(nil pipe))
			      (if (tramp-check-remote-uname v "Darwin")
				  (tramp-send-command
				   v "stty -icanon min 1 time 0")
				(tramp-send-command
				 v "stty -icrnl -icanon min 1 time 0")))
--8<---------------cut here---------------end--------------->8---

Pushed to the Emacs master branch. This patch will be contained also in
Tramp 2.6.0.2, scheduled for relase later this month on GNU ELPA.

Closing the bug.

> Thanks,
> Haiwei

Best regards, Michael.