> Uwe Brauer <oub@mat.ucm.es> writes:

Thanks for you response.


   > FWIW, I tried a set-up with git (I don't have mercurial available) and I cannot
   > reproduce this.

   > I'm not using numbered backups but the two variables you mention are set the
   > same way for me. Here's what I did:

A wait what do you mean you have not set up numbered backups, maybe this already is
the difference. I will come back to the point later

   > - created a directory "foo" and cd'ed to it.
   > - `git init'
   > - create "test.org" and export to create "test.tex".
   > - `git add test.org test.tex'
   > - `git status' to check that everything looks good.
   > - modify test.org and export a few times.
   > - at every export, do `ls -la'. I always get this:

   > ,----
   > | $ ls -la
   > | total 12
   > | drwxrwxr-x.  4 nick nick   62 Jun 21 13:04 .
   > | drwxrwxr-x. 14 nick nick 4096 Jun 21 13:03 ..
   > | drwxrwxr-x.  2 nick nick   21 Jun 21 13:04 auto
   > | drwxrwxr-x.  7 nick nick  132 Jun 21 13:04 .git
   > | -rw-rw-r--.  1 nick nick   67 Jun 21 13:04 test.org
   > | -rw-rw-r--.  1 nick nick  788 Jun 21 13:04 test.tex
   > `----

   > with no trace of backups.

Which is the expected behavior.


   > Maybe try with git and see if you can reproduce the problem?

I did and yes the problem also occurs in git, so the
problem is my setting not git/mercurial, which is good.


   > If not, I'd suspect either that the tex file is not under VC
   > or there is some incompatibility between mercurial and the
   > emacs vc package.

   > Also, there are two ways to make a backup (renaming and copying -
   > I use copying) and maybe the method you use is incompatible with
   > mercurial. Maybe you can try the other method: check the setting
   > of `make-backup-by-copying'.

I have a relatively recent version of GNU emacs master, but cannot find
the variables make-backup-by-copying. Could you please explain.


I had however 

backup-by-copying set nil, now it is t, but still the behavior is the
same.

So maybe it boils down to what you said at the beginning

   > I'm not using numbered backups
https://www.gnu.org/software/emacs/manual/html_node/elisp/Numbered-Backups.html

Ok I had 

Version-control set  to t.
I changed it to nil: no change 
I changed it to never: emacs now makes test.tex~ instead of test.tex.~1~

I am running out of ideas.

Where is the mistake?