merge(third_party/cgit): Import at master of 2020-01-11

Imported commit '723dc8fbcb' as
'third_party/cgit'.

third_party/cgit/tests/t0001-validate-git-versions.sh

@@ -0,0 +1,41 @@
+#!/bin/sh
+
+test_description='Check Git version is correct'
+CGIT_TEST_NO_CREATE_REPOS=YesPlease
+. ./setup.sh
+
+test_expect_success 'extract Git version from Makefile' '
+	sed -n -e "/^GIT_VER[ 	]*=/ {
+		s/^GIT_VER[ 	]*=[ 	]*//
+		p
+	}" ../../Makefile >makefile_version
+'
+
+# Note that Git's GIT-VERSION-GEN script applies "s/-/./g" to the version
+# string to produce the internal version in the GIT-VERSION-FILE, so we
+# must apply the same transformation to the version in the Makefile before
+# comparing them.
+test_expect_success 'test Git version matches Makefile' '
+	( cat ../../git/GIT-VERSION-FILE || echo "No GIT-VERSION-FILE" ) |
+	sed -e "s/GIT_VERSION[ 	]*=[ 	]*//" -e "s/\\.dirty$//" >git_version &&
+	sed -e "s/-/./g" makefile_version >makefile_git_version &&
+	test_cmp git_version makefile_git_version
+'
+
+test_expect_success 'test submodule version matches Makefile' '
+	if ! test -e ../../git/.git
+	then
+		echo "git/ is not a Git repository" >&2
+	else
+		(
+			cd ../.. &&
+			sm_sha1=$(git ls-files --stage -- git |
+				sed -e "s/^[0-9]* \\([0-9a-f]*\\) [0-9]	.*$/\\1/") &&
+			cd git &&
+			git describe --match "v[0-9]*" $sm_sha1
+		) | sed -e "s/^v//" -e "s/-/./" >sm_version &&
+		test_cmp sm_version makefile_version
+	fi
+'
+
+test_done