merge(third_party/git): Merge squashed git subtree at v2.23.0

Merge commit '1b593e1ea4' as 'third_party/git'

third_party/git/t/t4029-diff-trailing-space.sh

@@ -0,0 +1,43 @@
+#!/bin/sh
+#
+# Copyright (c) Jim Meyering
+#
+test_description='diff honors config option, diff.suppressBlankEmpty'
+
+. ./test-lib.sh
+
+cat <<\EOF >expected ||
+diff --git a/f b/f
+index 5f6a263..8cb8bae 100644
+--- a/f
++++ b/f
+@@ -1,2 +1,2 @@
+
+-x
++y
+EOF
+exit 1
+
+test_expect_success "$test_description" '
+	printf "\nx\n" > f &&
+	before=$(git hash-object f) &&
+	before=$(git rev-parse --short $before) &&
+	git add f &&
+	git commit -q -m. f &&
+	printf "\ny\n" > f &&
+	after=$(git hash-object f) &&
+	after=$(git rev-parse --short $after) &&
+	sed -e "s/^index .*/index $before..$after 100644/" expected >exp &&
+	git config --bool diff.suppressBlankEmpty true &&
+	git diff f > actual &&
+	test_cmp exp actual &&
+	perl -i.bak -p -e "s/^\$/ /" exp &&
+	git config --bool diff.suppressBlankEmpty false &&
+	git diff f > actual &&
+	test_cmp exp actual &&
+	git config --bool --unset diff.suppressBlankEmpty &&
+	git diff f > actual &&
+	test_cmp exp actual
+'
+
+test_done