diff-highlight settings break whitespace error color in some cases

[patrikndv]

When using the diff-highlight settings, the color.diff.whitespace color is sometimes overridden because the trailing whitespace error becomes colored by highlight instead. This seems to happen at least when the block of change is a single line that is changed to introduce whitespace error. In other words, something like:

-this is a changed line
+this is a changed line(WHITESPACE)

This will color the trailing whitespace in highlight instead of color.diff.whitespace.

[scottchiefbaker]

Are you able to provide a diff file the exhibits this behavior?

[phil-blain]

this diff shows the behaviour:

echo 'hello world'   > orig
echo 'hello world  ' > new
git diff --no-index orig new

i.e. the following diff:

diff --git 1/orig 2/new
index 3b18e51..36137e7 100644
--- 1/orig
+++ 2/new
@@ -1 +1 @@
-hello world
+hello world  

with no pager, the trailing whitespace is shown in highlighted red (the default for color.diff.whitespace is red reverse):

git -P diff --no-index orig new

result:

whereas with diff-so-fancy (or just diff-highlight) the trailing whitespace is highlighted in color.diff-highlight.newHighlight:

git diff --no-index orig new

(I'm using the colors suggested here: https://github.com/so-fancy/diff-so-fancy/blob/next/pro-tips.md#improved-colors-for-the-highlighted-bits.