[PATCH] changeset: add filename derived anchors to file diffs (and use them)

[Mads Kiilerich]

On 02/21/2016 09:59 PM, Angel Ezquerra wrote:
> # HG changeset patch
> # User Angel Ezquerra <angel.ezquerra at gmail.com>
> # Date 1456088218 -3600
> #      Sun Feb 21 21:56:58 2016 +0100
> # Branch stable
> # Node ID f1e465120793c9c7cad6baa4d78a00155bac4311
> # Parent  f7b771cc04c39f5d49b7b82397bd594db7285693
> changeset: add filename derived anchors to file diffs (and use them)
>
> Up until now it was not possible to create direct links to the file diffs within
> a changeset page because those links were created based on each file FID (which
> users cannot easily guess).
>
> This changeset adds anchors to each file diff. Each anchor name is derived from
> the corresponding filepath, which has been encoded to make it suitable to be
> used as URL anchor names as follows:
>
> 1. replace all forward slashes (/) with backward slashes (\)
> 2. (python urlib) URL quoting
> 3. replace all periods with exclamation marks
>
> This encoding is necessary (particularly the \ to / and . to ! mapping) because
> browsers have problems with anchors that contain forward slashes and periods.
>
> Note that the original FID link targets have not been removed. Thus this change
> should be transparent to the rest of Kallithea.

One feature of the existing FID is that it includes the revision hash 
and thus also generates unique ids for pages like 
https://kallithea-scm.org/repos/kallithea/changeset/494989b0ce72...b1bec568c0a2 
- it seems like your patch will make that URL generate (slightly) 
invalid html. That might be ok for the convenience this adds, but then 
that should be acknowledged explicitly.

The existing FID is defined in 
https://kallithea-scm.org/repos/kallithea/files/05a85a6cecba5c8caeb7996590365d5d9bc523c9/kallithea/lib/helpers.py#L123 
. It is not perfect but seems to me like it is significantly simpler 
than the alternative proposal. Especially because including "python 
urllib" in the specification sounds inconvenient for implementation in 
other languages and probably not is a place where Python guarantee 100% 
stability - especially not as various vulnerabilities are discovered.

It _could_ perhaps make sense to define a special format for "I don't 
care about revision" links ... but why not just set it to "" like for 
PRs and get ids like "C--067e5b4403fb".

So the current Python reference implementation for PR ids is:
"C--" + 
hashlib.md5(u'kallithea/templates/changelog/changelog_summary_data.html'.encode('utf8')).hexdigest()[:12]
- that must be easy to add to TortoiseHg.

Or using my favourite scripting language:
printf kallithea/templates/changelog/changelog_summary_data.html | 
md5sum |sed -ne 's,^\(.\{12\}\).*,C--\1,p'

Can it be much simpler?

(I guess one reason '.' generally should be avoided in ids is that it 
would be inconvenient when referencing it from css.)

/Mads