Prevent Vim from remembering a change

Question

I like the '. command in vim. From :help '.:

'.   `.

[Jump to] the position where the last change was made. The position is at or near where the change started.

Ok. But here's my problem: I use an autocmd function to add a "last modified" line in my file header. So, after every write, '. brings me not to my "real" last change, but to my file header. My current solution is I try to remember to mark my current editing point with ma, so I can 'a to return to it. I sometimes forget, though, and even when I remember, it's another couple keystrokes.

My ideal solution would be some sort of command that tells vim not to remember movements. I could send this command before the autocmd function jumps around, writing the last modified line, and then cancel it after the autocmd function has finished. That way, the location associated with '. would not be changed. However, I'm open to any other options that are more efficient.

In case you want to see it, here's what the autocmd does on :w.

function! UpdateHeader()
    let b:winview = winsaveview()

    " This is where I'd put the command to ignore future movements

    "The periods concatenate all the arguments into one command.
    "Silent! suppresses errors, usually 'pattern not found'
    "The 1,6g means search only lines 1 thru 6
    "Search for File Name: followed by anything
    "'s'ubstitute
    "Substitute in 'File Name: ' and the results of the expand command, on the
    "current filename
    execute "silent! 1," . 6 . "g/File Name:.*/s//File Name: " . expand("%")
    execute "silent! 1," . 6 . "g/Last Modified:.*/s//Last Modified: " . strftime("%d-%m-%Y")

    " This is where I'd put the command to start remembering movements again

    call winrestview(b:winview)
endfunction

Answer 1

You could use :keepjumps {command} in your autocmd.

See :help :keepjumps.

Answer 2

Try :lockmarks <command> in your autocmd. The help for this says that '. is one of the things will not be changed by the command.