[PATCH v2 3/6] parser: Add series parsing

[Russell Currey]

On Sun, 2016-09-04 at 01:24 +0100, Stephen Finucane wrote:
> From: Stephen Finucane <stephen.finucane at intel.com>
> 
> It is now possible to parse and store series, so do just that.
> The parsing at the moment is based on both RFC822 headers and
> subject lines.
> 
> Signed-off-by: Stephen Finucane <stephen.finucane at intel.com>
> Tested-by: Russell Currey <ruscur at russell.cc>
> ---

In testing v2 I found a weird issue I didn't find before.

If you send a new series in reply to the cover letter of a previous series, it
appends the patches to the previous series.  This is rather confusing as you
would think any patches sent in reply to a cover letter would belong to that
series, but they clearly should be treated differently in some cases, as you can
see in the screenshot below:

https://i.imgur.com/8Yi9IjR.png

(this is my test instance so it's not publicly accessible)

So it might be tricky to define what *does* deserve a new series in this case,
since:

- can't use author as some patches might be from a different author
- can't use date because what if someone sends patches at 23:59

Maybe use a reset in numbering?  This would be harder to parse if both series
had the same number of patches, I'm imagining something like the following:

- [1/3] patch sent in reply to cover letter, new series (#1)
- [2/3] patch sent in reply to cover letter, append to #1
- [3/3] patch sent in reply to cover letter, append to #1
- [1/3] patch sent in reply to cover letter, new series (#2)
- [2/3] patch sent in reply to cover letter:
	- see that series #2 doesn't have a 2/3
	- see that the date of the patch means it's probably for series #2
	- append to series #2
- [3/3] is the same as above.

That's probably confusing...but hopefully there's a simple solution.  If an
automated system was testing series, applying every patch in the series in the
image above would not be what you wanted.

- Russell