Thanks for the consideration.Unless there's an internal bug with TMPSUFFIX, I can only think of one way this patch could go wrong, and it's pretty obscure:
Suppose I have a "smart editor" that attempts to decide what program to run based on file extension (opens .xls as a spreadsheet, .doc with a word processor, etc.) Suppose further that this "editor" opens files ending in ".perl", ".zsh", ".sh", etc. by running the corresponding interpreter. Oops, I've just executed the command line I meant to edit. This is not entirely far-fetched, if you're on a Mac and have XCode fully installed, "open /tmp/blablah.zsh" may actually run zsh. Is this worth worrying about?
At least it does not reproduce on my Mac, where Xcode is opened
for editing the script. On Ubuntu Desktop, .zsh is associated
with gedit by default. If one dares to change that to make
double-clicking in general unsafe and then set EDITOR to
open/start as well, I say they are shooting their own foot.
Akinori MUSHA / https://akinori.org/