Re: [idea] File history tracking hints

["Philip Oakley" <philipoakley@iee.org>]

From: "Pavel Kretov" <firegurafiku@gmail.com>
> Hi all,
>
> Excuse me if the topic I'm going to raise here has been already discussed
> on the mailing list, forums, or IRC, but I couldn't find anything related.
>
>
> The problem:
>
> Git, being "a stupid content tracker", doesn't try to keep an eye on
> operations which happens to individual files; things like file renames
> aren't recorded during commit, but heuristically detected later.
>
> Unfortunately, the heuristic can only deal with simple file renames with
> no substantial content changes; it's helpless when you:
>
> - rename file and change it's content significantly;
> - split single file into several files;
> - merge several files into another;
> - copy entire file from another commit, and do other things like these.
>
> However, if we're able to preserve this information, it's possible
> not only to do more accurate 'git blame', but also merge revisions with
> fewer conflicts.
>
>
> The proposal:
>
> The idea is to let user give hints about what was changed during
> the commit. For example, if user did a rename which wasn't automatically
> detected, he would append something like the following to his commit
> message:
>
>    Tracking-hints: rename dev-vcs/git/git-1.0.ebuild ->
> dev-vcs/git/git-2.0.ebuild
>
> or (if full paths of affected files can be unambiguously omitted):
>
>    Tracking-hints: rename git-1.0.ebuild -> git-2.0.ebuild
>
> There may be other hint types:
>
>    Tracking-hint: recreate LICENSE.txt
>    Tracking-hint: split main.c -> main.c cmdline.c
>    Tracking-hint: merge linalg.py <- vector.py matrix.py
>
> or even something like this:
>
>    Tracking-hint: copy json.py <-
> libs/json.py@4db88291251151d8c5c8e4f20430fa4def2cb2ed
>
> If file transformation cannot be described by a single tracking hint, it 
> shall
> be possible to specify a sequence of hints at once:
>
>    Tracking-hint:
>        split Utils.java -> AppHelpers.java StringHelpers.java
>        recreate Utils.java
>
> Note that in the above example the order of operations really matters, so
> both lines have to reside in one 'Tracking-hint' block.
>
> * * *
>
> How do you think, is this idea worth implementing?
> Any other thoughts on this?
>
> -- Pavel Kretov.

Maybe use the "interpret-trailers" methods for standardising your hints 
locally (in your team / workplace) to see how it goes and flesh out what 
works and what doesn't. Trying to decide, a-priori, what are the right hints 
is likely to be the hard part.
--
Philip