bug#63872: [PATCH] `mouse-drag-and-drop-region' sometimes couldn't cut

[Stefan Kangas]

Po Lu <luangruo@yahoo.com> writes:

> Stefan Kangas <stefankangas@gmail.com> writes:
>
>> The video shows that text is copied also when the buffer which receives
>> the drop is the same as the source buffer.
>>
>> Is that the intended behavior?  It seems off, to me.
>
> I can't download that attachment, so would you please summarize its
> contents?  The important detail is whether the destination window is the
> same as the source.

I can reproduce this on current master with the following steps:

0. emacs -Q
1. Evaluate this in *scratch*:

    (custom-set-variables
     '(mark-even-if-inactive nil)
     '(mouse-drag-and-drop-region t))

2. Mark some text with the mouse, and then drag and drop it into the
   same window.

The result is that the text is copied.  This is also what happens in the
video.

In GNU Emacs 30.0.50 (build 12, x86_64-apple-darwin21.6.0, NS
 appkit-2113.60 Version 12.6.8 (Build 21G725)) of 2023-09-06 built on
 MY-MacBook-Pro
Repository revision: c3584bb3ab6f442a837464e191182f713acc3be3
Repository branch: master
Windowing system distributor 'Apple', version 10.3.2113
System Description:  macOS 12.6.8

Configured features:
ACL GIF GMP GNUTLS JPEG JSON LCMS2 LIBXML2 MODULES NOTIFY KQUEUE NS
PDUMPER PNG SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER WEBP
XIM ZLIB