tests/test-strict.t

hgweb: add HTML elements to control whitespace settings for annotate

Building on top of the new URL query string arguments to control
whitespace settings for annotate, this commit adds HTML checkboxes
reflecting the values of these arguments to the paper and gitweb
themes.

The actual diff settings are now exported to the templating layer.
The HTML templates add these as data-* attributes so they are
accessible to the DOM.

A new <form> with various <input> elements is added. The <form>
is initially hidden via CSS. A shared JavaScript function (which
runs after the <form> has been rendered but before the annotate
HTML (because annotate HTML could take a while to load and we want
the form to render quickly) takes care of setting the checked state
of each box from the data-* attributes. It also registers an event
handler to modify the URL and refresh the page whenever the checkbox
state is changed.

I'm using the URLSearchParams interface to perform URL manipulation.
https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams tells
me this may not be supported on older web browsers. Yes, apparently
the web API didn't have a standard API to parse and format query
strings until recently. Hence the check for the presence of this
feature in the JavaScript. If the browser doesn't support the
feature, the <form> will remain hidden and behavior will like it
currently is. We could polyfill this feature or implement our own
query string parsing. But I'm lazy and this could be done as a
follow-up if people miss it.

We could certainly expand this feature to support more diff options
(such as lines of context). That's why the potentially reusable code
is stored in a reusable place. It is also certainly possible to
add diff controls to other pages that display diffs. But since
Mozillians are making noise about controlling which revisions
annotate shows, I figured I'd start there.

.. feature::

   Control whitespace settings for annotation on hgweb

   /annotate URLs on hgweb now accept query string arguments to
   influence how whitespace changes impact results.

   The arguments "ignorews," "ignorewsamount," "ignorewseol," and
   "ignoreblanklines" now have the same meaning as their [annotate]
   config section counterparts. Any provided setting overrides the
   server default.

   HTML checkboxes have been added to the paper and gitweb themes
   to expose current whitespace settings and to easily modify the
   current view.

Differential Revision: https://phab.mercurial-scm.org/D850

  $ hg init

  $ echo a > a
  $ hg ci -Ama
  adding a

  $ hg an a
  0: a

  $ hg --config ui.strict=False an a
  0: a

  $ echo "[ui]" >> $HGRCPATH
  $ echo "strict=True" >> $HGRCPATH

  $ hg an a
  hg: unknown command 'an'
  Mercurial Distributed SCM
  
  basic commands:
  
   add           add the specified files on the next commit
   annotate      show changeset information by line for each file
   clone         make a copy of an existing repository
   commit        commit the specified files or all outstanding changes
   diff          diff repository (or selected files)
   export        dump the header and diffs for one or more changesets
   forget        forget the specified files on the next commit
   init          create a new repository in the given directory
   log           show revision history of entire repository or files
   merge         merge another revision into working directory
   pull          pull changes from the specified source
   push          push changes to the specified destination
   remove        remove the specified files on the next commit
   serve         start stand-alone webserver
   status        show changed files in the working directory
   summary       summarize working directory state
   update        update working directory (or switch revisions)
  
  (use 'hg help' for the full list of commands or 'hg -v' for details)
  [255]
  $ hg annotate a
  0: a

should succeed - up is an alias, not an abbreviation

  $ hg up
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved