bug#34891: 25.2; ORG-PUBLISH-FIND-DATE should not use Creation/Publish date (#+DATE:) in file as a modification timestamp.

[Nicolas Goaziou <mail@nicolasgoaziou.fr>]

Hello,

David Trudgett <david.trudgett@eclecticse.com.au> writes:

> Reproduce:
>
> In an Org mode file, add a #+DATE tag as follows:
>
> #+DATE: First published: 1 February 2014
>
> Then initiate a project publish, which publishes (by default) only
> changed files. A date such as the above will not be parsed, so
> ox-publish.el will always publish it, even though it has not changed.
> Using instead a parsable date format (such as 2014-02-01), this date will be
> recognised, and will result in the file never being published, because
> it is treating the date as a modification date instead of a creation date.
>
> Desired Behaviour:
>
> ox-publish.el, in function ORG-PUBLISH-FIND-DATE should not be using
> this date to detect modifications, as it will never change, and no
> modifications will be detected for publishing.

I don't understand how you come to this conclusion. 

The function responsible for deciding if a file should be published is
`org-publish-cache-file-needs-publishing'. It doesn't call
`org-publish-find-date', but `org-publish-cache-ctime-of-src'. The
latter only uses `file-attribute-modification-time'.

IOW, I think the file is published because you modified since last
publishing.

WDYT?

Regards,

-- 
Nicolas Goaziou