Merge branch 'jk/http-test-cgipassauth-unavailable-in-older-apache'

We started unconditionally testing with CGIPassAuth directive but
it is unavailable in older Apache that ships with CentOS 7 that has
about a year of shelf-life still left.  The test has conditionally
been disabled when running with an ancient Apache.  This was a fix
for a recent regression caught before the release, so no need to
mention it in the release notes.

* jk/http-test-cgipassauth-unavailable-in-older-apache:
  t/lib-httpd: make CGIPassAuth support conditional
diff --git a/t/lib-httpd.sh b/t/lib-httpd.sh
index 6805229..2fb1b2a 100644
--- a/t/lib-httpd.sh
+++ b/t/lib-httpd.sh
@@ -191,6 +191,20 @@
 	test_set_prereq HTTP2
 }
 
+enable_cgipassauth () {
+	# We are looking for 2.4.13 or more recent. Since we only support
+	# 2.4 and up, no need to check for older major/minor.
+	if test "$HTTPD_VERSION_MAJOR" = 2 &&
+	   test "$HTTPD_VERSION_MINOR" = 4 &&
+	   test "$(echo $HTTPD_VERSION | cut -d. -f3)" -lt 13
+	then
+		echo >&4 "apache $HTTPD_VERSION too old for CGIPassAuth"
+		return
+	fi
+	HTTPD_PARA="$HTTPD_PARA -DUSE_CGIPASSAUTH"
+	test_set_prereq CGIPASSAUTH
+}
+
 start_httpd() {
 	prepare_httpd >&3 2>&4
 
diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 9e68929..a22d138 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -146,7 +146,9 @@
 <LocationMatch /custom_auth/>
 	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
 	SetEnv GIT_HTTP_EXPORT_ALL
+	<IfDefine USE_CGIPASSAUTH>
 	CGIPassAuth on
+	</IfDefine>
 </LocationMatch>
 ScriptAlias /smart/incomplete_length/git-upload-pack incomplete-length-upload-pack-v2-http.sh/
 ScriptAlias /smart/incomplete_body/git-upload-pack incomplete-body-upload-pack-v2-http.sh/
diff --git a/t/t5563-simple-http-auth.sh b/t/t5563-simple-http-auth.sh
index f45a43b..ab8a721 100755
--- a/t/t5563-simple-http-auth.sh
+++ b/t/t5563-simple-http-auth.sh
@@ -5,6 +5,12 @@
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-httpd.sh
 
+enable_cgipassauth
+if ! test_have_prereq CGIPASSAUTH
+then
+	skip_all="no CGIPassAuth support"
+	test_done
+fi
 start_httpd
 
 test_expect_success 'setup_credential_helper' '