t1300: test mixed-case variable retrieval

We should be able to ask for a config value both by its
canonical all-lowercase name (as git does internally), as
well as by random mixed-case (which will be canonicalized by
git-config for us).

Subsections are a tricky point, though. Since we have both

  [section "Foo"]

and

  [section.Foo]

you might want git-config to canonicalize the subsection or
not, depending on which you are expecting. But there's no
way to communicate this; git-config sees only the key, and
doesn't know which type of section name will be in the
config file.

So it must leave the subsection intact, and it is up to the
caller to provide a canonical version of the subsection if
they want to match the latter form.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t1300-repo-config.sh

@@ -73,6 +73,33 @@ EOF
 
 test_expect_success 'non-match result' 'test_cmp expect .git/config'
 
+test_expect_success 'find mixed-case key by canonical name' '
+	echo Second >expect &&
+	git config cores.whatever >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'find mixed-case key by non-canonical name' '
+	echo Second >expect &&
+	git config CoReS.WhAtEvEr >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'subsections are not canonicalized by git-config' '
+	cat >>.git/config <<-\EOF &&
+	[section.SubSection]
+	key = one
+	[section "SubSection"]
+	key = two
+	EOF
+	echo one >expect &&
+	git config section.subsection.key >actual &&
+	test_cmp expect actual &&
+	echo two >expect &&
+	git config section.SubSection.key >actual &&
+	test_cmp expect actual
+'
+
 cat > .git/config <<\EOF
 [alpha]
 bar = foo