if you invoke a special mode while visting a file not intended for that mode
sound interesting to test... in my case the file has been in org mode from the beginning, and to be honest I am unsure I understand "not intended for that mode". I mean, if I visit plain text files, I guess it does not matter which mode I invoke, right? 

About git -- totally. It's just that unexplained bugs add to the paranoia feeling. 

By the way, I have started to test my theory that the bug has to do with the file size, but so far I have not been able to reproduce the bug.

/ Dmitry


On Mon, Feb 15, 2021 at 12:36 PM Eric S Fraga <e.fraga@ucl.ac.uk> wrote:
On Friday, 12 Feb 2021 at 11:29, Dmitry Knyaginin wrote:
> I have some wild theories, including a gamma particle hitting my laptop ;)

Something I saw on the emacs developer list: if you invoke a special
mode while visting a file not intended for that mode, it is possible for
contents to be deleted and no undo information kept.  I don't have more
details than this unfortunately.  Luckily, I've never run into this but,
then again, I don't usually invoke a mode switching command explicitly.

I'm glad you could get some (all?) of what you lost from git.  Another
data point pushing everybody to use version control systems!

--
: Eric S Fraga via Emacs 28.0.50, Org release_9.4.4-213-g49364f