Tidy the test comments and shell portability

1 file changed, 16 insertions, 8 deletions

diff --git a/tests/t0001-validate-git-versions.sh b/tests/t0001-validate-git-versions.sh
index 65c3c6a..2117764 100755
--- a/tests/t0001-validate-git-versions.sh
+++ b/tests/t0001-validate-git-versions.sh
@@ -1,5 +1,12 @@
 #!/bin/sh
 
+# Checks that the Git version cgit says it is built for is the one it is
+# actually built against. The top-level Makefile names a version, the tree
+# under vendor/git records its own, and the submodule is pinned to a tag, so
+# all three have to agree or cgit is being built on something other than what
+# it claims. Set CGIT_TEST_NO_GIT_VERSION to YesPlease when Git comes from
+# elsewhere and the comparison has nothing to say.
+
 if [ "${CGIT_TEST_NO_GIT_VERSION}" = "YesPlease" ]; then
 	exit 0
 fi
@@ -15,10 +22,9 @@ test_expect_success 'extract Git version from Makefile' '
 	}" ../../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.
+# Git's GIT-VERSION-GEN script applies "s/-/./g" to the version string on its
+# way into the GIT-VERSION-FILE, so the same has to be done to the version in
+# the Makefile before the two can be compared.
 test_expect_success 'test Git version matches Makefile' '
 	( cat ../../vendor/git/GIT-VERSION-FILE || echo "No GIT-VERSION-FILE" ) |
 	sed -e "s/GIT_VERSION[ 	]*=[ 	]*//" -e "s/\\.dirty$//" >git_version &&
@@ -26,6 +32,8 @@ test_expect_success 'test Git version matches Makefile' '
 	test_cmp git_version makefile_git_version
 '
 
+# A tree unpacked from a tarball has no submodule pin to describe, so there is
+# nothing to compare against and the test says so rather than failing.
 test_expect_success 'test submodule version matches Makefile' '
 	if ! test -e ../../vendor/git/.git
 	then
@@ -33,12 +41,12 @@ test_expect_success 'test submodule version matches Makefile' '
 	else
 		(
 			cd ../.. &&
-			sm_oid=$(git ls-files --stage -- vendor/git |
+			submodule_oid=$(git ls-files --stage -- vendor/git |
 				sed -e "s/^[0-9]* \\([0-9a-f]*\\) [0-9]	.*$/\\1/") &&
 			cd vendor/git &&
-			git describe --match "v[0-9]*" $sm_oid
-		) | sed -e "s/^v//" -e "s/-/./" >sm_version &&
-		test_cmp sm_version makefile_version
+			git describe --match "v[0-9]*" $submodule_oid
+		) | sed -e "s/^v//" -e "s/-/./" >submodule_version &&
+		test_cmp submodule_version makefile_version
 	fi
 '