[Checkins] [zopefoundation/Zope] 76bfc1: New branch to fix TAL default handling (#853)

[Jens Vagelpohl]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/Zope
  Commit: 76bfc13dbf24a8b34ffafb53f2109bff2712b15f
      https://github.com/zopefoundation/Zope/commit/76bfc13dbf24a8b34ffafb53f2109bff2712b15f
  Author: Jens Vagelpohl <jens at netz.ooo>
  Date:   2020-06-26 (Fri, 26 Jun 2020)

  Changed paths:
    M constraints.txt
    M requirements-full.txt
    M src/Products/PageTemplates/engine.py
    A src/Products/PageTemplates/tests/input/BooleanAttributes.html
    M src/Products/PageTemplates/tests/input/Default.html
    A src/Products/PageTemplates/tests/output/BooleanAttributes.html
    M src/Products/PageTemplates/tests/output/Default.html
    M src/Products/PageTemplates/tests/testHTMLTests.py
    M versions-prod.cfg

  Log Message:
  -----------
  New branch to fix TAL default handling (#853)

* - new branch to fix TAL default handling

* adapt to changed default handling of `chameleon==3.7.4` (does not yet work

* Python 3 compatibility

* - use Chameleon 3.8

* Adaptations for `chameleon>=3.8`

* - fix lint issue

* - add test for straight boolean after seeing malthe/chameleon#318

* - comment change [ci skip]

Co-authored-by: dieter <dieter at handshake.de>