Make ':extend' inherited from default spec unless overridden

* lisp/faces.el (face-spec-recalc): Handle the :extend attribute
specially and always inherit it from the default spec unless
overwritten in a theme (bug#37774).

* test/lisp/faces-tests.el (faces--test-data-dir): New variable.
(faces--test-extend-with-themes): Use test themes instead of ones
from etc/themes.  Update expected values.

* test/data/themes/faces-test-dark-theme.el: New file.

* test/data/themes/faces-test-light-theme.el: New file.

* doc/lispref/display.texi (Face Attributes):
Update the description of ':extend'.

* etc/NEWS: Update the entry for ':extend'.

* etc/themes/adwaita-theme.el:
* etc/themes/deeper-blue-theme.el:
* etc/themes/dichromacy-theme.el:
* etc/themes/leuven-theme.el:
* etc/themes/light-blue-theme.el:
* etc/themes/manoj-dark-theme.el:
* etc/themes/misterioso-theme.el:
* etc/themes/tango-dark-theme.el:
* etc/themes/tango-theme.el:
* etc/themes/tsdh-dark-theme.el:
* etc/themes/tsdh-light-theme.el:
* etc/themes/wheatgrass-theme.el:
* etc/themes/wombat-theme.el: Remove the now-redundant ':extend'
attribute in all the themes.

1 files changed, 5 insertions, 5 deletions

diff --git a/etc/themes/tsdh-dark-theme.el b/etc/themes/tsdh-dark-theme.el
index bd0564a21dc..5482ced6b29 100644
--- a/etc/themes/tsdh-dark-theme.el
+++ b/etc/themes/tsdh-dark-theme.el
@@ -26,12 +26,12 @@
  'tsdh-dark
  '(aw-leading-char-face ((t (:background "gray30" :foreground "red" :weight bold))))
  '(default ((t (:background "gray20" :foreground "white smoke"))))
- '(diff-added ((t (:inherit diff-changed :background "dark green" :extend t))) t)
+ '(diff-added ((t (:inherit diff-changed :background "dark green"))) t)
  '(diff-changed ((t (:background "midnight blue"))) t)
  '(diff-indicator-added ((t (:inherit diff-indicator-changed))) t)
  '(diff-indicator-changed ((t (:weight bold))) t)
  '(diff-indicator-removed ((t (:inherit diff-indicator-changed))) t)
- '(diff-removed ((t (:inherit diff-changed :background "dark red" :extend t))) t)
+ '(diff-removed ((t (:inherit diff-changed :background "dark red"))) t)
  '(dired-directory ((t (:foreground "DodgerBlue" :weight bold))))
  '(error ((t (:foreground "deep pink" :weight bold))))
  '(eshell-prompt ((t (:inherit font-lock-function-name-face :weight bold))))
@@ -69,7 +69,7 @@
  '(header-line ((t (:inverse-video t :box (:line-width -1 :color "red" :style released-button)))))
  '(helm-header ((t (:background "DeepSkyBlue4" :weight bold))))
  '(highlight ((t (:background "sea green"))))
- '(hl-line ((t (:background "grey25" :extend t))))
+ '(hl-line ((t (:background "grey25"))))
  '(hl-paren-face ((t (:weight bold))) t)
  '(icomplete-first-match ((t (:foreground "deep sky blue" :weight bold))))
  '(ido-first-match ((t (:foreground "turquoise" :weight bold))))
@@ -132,9 +132,9 @@
  '(rcirc-other-nick ((t (:foreground "dodger blue"))) t)
  '(rcirc-track-keyword ((t (:foreground "DodgerBlue" :weight bold))) t)
  '(rcirc-track-nick ((t (:background "yellow" :foreground "DodgerBlue" :weight bold))) t)
- '(region ((t (:background "SeaGreen4" :extend t))))
+ '(region ((t (:background "SeaGreen4"))))
  '(scroll-bar ((t (:background "gray20" :foreground "dark turquoise"))))
- '(secondary-selection ((t (:background "#333366" :foreground "#f6f3e8" :extend t))))
+ '(secondary-selection ((t (:background "#333366" :foreground "#f6f3e8"))))
  '(show-paren-match ((t (:background "DeepSkyBlue4"))))
  '(show-paren-mismatch ((t (:background "dark magenta"))))
  '(swiper-match-face-1 ((t (:background "gray35"))))