From 6bfdfeed36fab4680c8db90c22da8f6611694186 Mon Sep 17 00:00:00 2001
From: Juri Linkov <juri@linkov.net>
Date: Wed, 10 Feb 2021 21:37:47 +0200
Subject: [PATCH] Fix ediff even/odd faces to increase their contrast and
 readability

* lisp/vc/ediff-init.el (ediff-even-diff-A, ediff-even-diff-B)
(ediff-even-diff-C, ediff-even-diff-Ancestor, ediff-odd-diff-A)
(ediff-odd-diff-B, ediff-odd-diff-C): Add :distant-foreground
"Black" for light background.  For dark background
add :distant-foreground "White", and use darker shades of grey
for background colors (bug#46396).
---
 lisp/vc/ediff-init.el | 42 ++++++++++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/lisp/vc/ediff-init.el b/lisp/vc/ediff-init.el
index 6e658163b91..3f33e6aae2e 100644
--- a/lisp/vc/ediff-init.el
+++ b/lisp/vc/ediff-init.el
@@ -980,8 +980,10 @@ this variable represents.")
 (defface ediff-even-diff-A
   `((((type pc))
      (:foreground "green3" :background "light grey" :extend t))
-    (((class color) (min-colors 88))
-     (:background "light grey" :extend t))
+    (((class color) (min-colors 88) (background light))
+     (:distant-foreground "Black" :background "light grey" :extend t))
+    (((class color) (min-colors 88) (background dark))
+     (:distant-foreground "White" :background "dark grey" :extend t))
     (((class color) (min-colors 16))
      (:foreground "Black" :background "light grey" :extend t))
     (((class color))
@@ -999,8 +1001,10 @@ widget to customize the actual face object `ediff-even-diff-A'
 this variable represents.")
 
 (defface ediff-even-diff-B
-  `((((class color) (min-colors 88))
-     (:background "Grey" :extend t))
+  `((((class color) (min-colors 88) (background light))
+     (:distant-foreground "Black" :background "Grey" :extend t))
+    (((class color) (min-colors 88) (background dark))
+     (:distant-foreground "White" :background "dim grey" :extend t))
     (((class color) (min-colors 16))
      (:foreground "White" :background "Grey" :extend t))
     (((class color))
@@ -1019,8 +1023,10 @@ this variable represents.")
 (defface ediff-even-diff-C
   `((((type pc))
      (:foreground "yellow3" :background "light grey" :extend t))
-    (((class color) (min-colors 88))
-     (:background "light grey" :extend t))
+    (((class color) (min-colors 88) (background light))
+     (:distant-foreground "Black" :background "light grey" :extend t))
+    (((class color) (min-colors 88) (background dark))
+     (:distant-foreground "White" :background "dark grey" :extend t))
     (((class color) (min-colors 16))
      (:foreground "Black" :background "light grey" :extend t))
     (((class color))
@@ -1040,8 +1046,10 @@ this variable represents.")
 (defface ediff-even-diff-Ancestor
   `((((type pc))
      (:foreground "cyan3" :background "light grey" :extend t))
-    (((class color) (min-colors 88))
-     (:background "Grey" :extend t))
+    (((class color) (min-colors 88) (background light))
+     (:distant-foreground "Black" :background "Grey" :extend t))
+    (((class color) (min-colors 88) (background dark))
+     (:distant-foreground "White" :background "dim grey" :extend t))
     (((class color) (min-colors 16))
      (:foreground "White" :background "Grey" :extend t))
     (((class color))
@@ -1068,8 +1076,10 @@ this variable represents.")
 (defface ediff-odd-diff-A
   '((((type pc))
      (:foreground "green3" :background "gray40" :extend t))
-    (((class color) (min-colors 88))
-     (:background "Grey" :extend t))
+    (((class color) (min-colors 88) (background light))
+     (:distant-foreground "Black" :background "Grey" :extend t))
+    (((class color) (min-colors 88) (background dark))
+     (:distant-foreground "White" :background "dim grey" :extend t))
     (((class color) (min-colors 16))
      (:foreground "White" :background "Grey" :extend t))
     (((class color))
@@ -1088,8 +1098,10 @@ this variable represents.")
 (defface ediff-odd-diff-B
   '((((type pc))
      (:foreground "White" :background "gray40" :extend t))
-    (((class color) (min-colors 88))
-     (:background "light grey" :extend t))
+    (((class color) (min-colors 88) (background light))
+     (:distant-foreground "Black" :background "light grey" :extend t))
+    (((class color) (min-colors 88) (background dark))
+     (:distant-foreground "White" :background "dark grey" :extend t))
     (((class color) (min-colors 16))
      (:foreground "Black" :background "light grey" :extend t))
     (((class color))
@@ -1108,8 +1120,10 @@ this variable represents.")
 (defface ediff-odd-diff-C
   '((((type pc))
      (:foreground "yellow3" :background "gray40" :extend t))
-    (((class color) (min-colors 88))
-     (:background "Grey" :extend t))
+    (((class color) (min-colors 88) (background light))
+     (:distant-foreground "Black" :background "Grey" :extend t))
+    (((class color) (min-colors 88) (background dark))
+     (:distant-foreground "White" :background "dim grey" :extend t))
     (((class color) (min-colors 16))
      (:foreground "White" :background "Grey" :extend t))
     (((class color))
-- 
2.39.2