t/lib-git-svn.sh: check GIT_TEST_SVN_HTTPD when running SVN HTTP tests

Once upon a time the GIT_SVN_TEST_HTTPD environment variable needed to
be set to enable SVN HTTP tests [1].

Then 3b072c5 (tests: replace test_tristate with "git env--helper",
2019-06-21) came along, and attempted to turn GIT_SVN_TEST_HTTPD into
a bool, but while doing so it mistyped the variable name, and started
to check GIT_TEST_HTTPD instead.  Consequently, if someone explicitly
set GIT_TEST_HTTPD to true and has only the general 'git-svn'
dependencies installed but not the Subversion server modules for
Apache (libapache2-mod-svn), then a couple of 'git-svn' tests fail,
because they can't start httpd due to the missing module.

We could simply fix this by checking the GIT_SVN_TEST_HTTPD
variablewith 'git env--helper', but notice that the name of this
variable doesn't conform to our usual GIT_TEST_* convention.

So let's check the GIT_TEST_SVN_HTTPD instead.

[1] a8a5d25 (git svn: migrate tests to use lib-httpd, 2016-07-23)

Signed-off-by: SZEDER Gábor <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: szeder

t/lib-git-svn.sh

@@ -69,7 +69,7 @@ svn_cmd () {
 maybe_start_httpd () {
 	loc=${1-svn}
 
-	if git env--helper --type=bool --default=false --exit-code GIT_TEST_HTTPD
+	if git env--helper --type=bool --default=false --exit-code GIT_TEST_SVN_HTTPD
 	then
 		. "$TEST_DIRECTORY"/lib-httpd.sh
 		LIB_HTTPD_SVN="$loc"