Subject: bug#32883: 26.1; Emacs not response in shell mode

From: Eli Zaretskii <[email-masked]>
Date: Sun, 30 Sep 2018 20:06:02 +0300

> From: "alexei28" <[email-masked]>
> Cc: <[email-masked]>
> Date: Sun, 30 Sep 2018 18:14:35 +0300
> 
> I do the another test.
> 1. M-x shell
> 2. Open some text file (about 2 MB) by command  "cat some_text.txt".
> In shell mode something like this:
> 
> Microsoft Windows [Version 10.0.17134.285]
> (c) 2018 Microsoft Corporation. All rights reserved.
> 
> d:\TEMP\temp>cat trace.log.2018-08-09
> 
> 4. Start command
> 5. And while file is scrolling I press arrow up. As result cursor is on the
> center of screen
> 6. Press Enter
> 7. And Emacs also "freeze". Not response. In this case Emacs is not response
> only when file is opening (scrolling). 
> 8. After "cat" finish the Emacs is success unlock. In this case (file size =
> 2 MB) it's unlock after 30 seconds. 
> But suppose file has size 200 MB. It's then unlock after one hour?
> It's not good.

But that is what is supposed to happen.  When you press Enter,
shell-mode takes all the stuff between the point where you pressed
Enter and the end of output, and submits that to the shell.  Since
that's a lot of text, it could take a long time to process.

So just don't do that, it makes no sense to do that in the situation
you describe.