bug#49253: 27.2; Emacs non-responsive when pasting into terminal-mode

[Jared Finder via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

On 2023-12-09 03:10, Eli Zaretskii wrote:
> Jared, can I ask you to look into this and share your thoughts and
> comments to the proposed change?  TIA.
> 
>> Cc: 49253@debbugs.gnu.org
>> From: Matt Bisson <bisson.m@gmail.com>
>> Date: Fri, 8 Dec 2023 15:35:36 -0500
>> 
>> Right, so this silly little fix works, but it's an obvious hack.  I
>> clearly don't know enough about how the key-bindings work, because I
>> would have expected those set by term-mode to override those in the
>> global keybindings (from xterm.el), but they don't.  The xterm.el one
>> runs first.  Here's the diff:
>> 
>> diff --git a/lisp/term.el b/lisp/term.el
>> index 81746e0c20d..e047fa767e8 100644
>> --- a/lisp/term.el
>> +++ b/lisp/term.el
>> @@ -956,6 +956,7 @@ term-raw-map
>>      (define-key map [?\C- ] #'term-send-C-@)
>>      (define-key map [?\C-\M-/] #'term-send-C-M-_)
>>      (define-key map [?\C-\M- ] #'term-send-C-M-@)
>> +    (define-key map "\e[200~" #'term--xterm-paste)
>> 
>>      (when term-bind-function-keys
>>        (dotimes (key 21)

Thanks for the investigation.  I don't think this is the right approach. 
  The xterm escape codes all go through input-decode-map and I would 
expect to preserve that.

Looking at code, the current behavior in xterm.el is the following:

Step 1: \e[200~ is put on input-decode-map, using 
xterm-translate-backeted-paste to decode.

Step 2: The function xterm-translate-bracketed-paste reads the pasted 
text and creates an event (xterm-paste "PASTED TEXT HERE")

Step 3: Globally, the event xterm-paste is bound to the function also 
named xterm-paste, which grabs the pasted text and puts it on the kill 
ring, then runs the function insert-for-yank.

Step 3a: In Term mode, the event xterm-paste is instead bound to the 
function term--xterm-paste.  However, instead of reading the pasted text 
off the event, it calls (xterm-pasted-text) again.

I think the correct fix is to change term--xterm-paste to read the 
pasted text off of the event generated in Step 2.  So something like the 
following (a real fix would add error checking like in xterm-paste):

(defun term--xterm-paste (event)
   "Insert the text pasted in an XTerm bracketed paste operation."
   (interactive "e")
   (term-send-raw-string (nth 1 event)))

Matt, can you try this change locally?  It worked for me.

   -- MJF