[PATCH 2/3] config: fix case sensitive subsection names on writing

[Stefan Beller <sbeller@google.com>]

A use reported a submodule issue regarding strange case indentation
issues, but it could be boiled down to the following test case:

  $ git init test  && cd test
  $ git config foo."Bar".key test
  $ git config foo."bar".key test
  $ tail -n 3 .git/config
  [foo "Bar"]
        key = test
        key = test

Sub sections are case sensitive and we have a test for correctly reading
them. However we do not have a test for writing out config correctly with
case sensitive subsection names, which is why this went unnoticed in
6ae996f2acf (git_config_set: make use of the config parser's event
stream, 2018-04-09)

Make the subsection case sensitive and provide a test for writing.
The test for reading is just above this test.

Reported-by: JP Sugarbroad <jpsugar@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 config.c          | 2 +-
 t/t1300-config.sh | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/config.c b/config.c
index 7968ef7566a..de646d2c56f 100644
--- a/config.c
+++ b/config.c
@@ -2362,7 +2362,7 @@ static int store_aux_event(enum config_event_t type,
 		store->is_keys_section =
 			store->parsed[store->parsed_nr].is_keys_section =
 			cf->var.len - 1 == store->baselen &&
-			!strncasecmp(cf->var.buf, store->key, store->baselen);
+			!strncmp(cf->var.buf, store->key, store->baselen);
 		if (store->is_keys_section) {
 			store->section_seen = 1;
 			ALLOC_GROW(store->seen, store->seen_nr + 1,
diff --git a/t/t1300-config.sh b/t/t1300-config.sh
index ced13012409..e5d16f53ee1 100755
--- a/t/t1300-config.sh
+++ b/t/t1300-config.sh
@@ -1250,6 +1250,7 @@ test_expect_success 'old-fashioned settings are case insensitive' '
 	q_to_tab >testConfig_expect <<-EOF &&
 		[V.A]
 		r = value1
+		[V "A"]
 		Qr = value2
 	EOF
 	git config -f testConfig_actual "V.A.r" value2 &&
@@ -1262,6 +1263,7 @@ test_expect_success 'old-fashioned settings are case insensitive' '
 	q_to_tab >testConfig_expect <<-EOF &&
 		[V.A]
 		r = value1
+		[v "A"]
 		Qr = value2
 	EOF
 	git config -f testConfig_actual "v.A.r" value2 &&
@@ -1290,6 +1292,7 @@ test_expect_success 'setting different case sensitive subsections ' '
 		Qc = v2
 		[d "e"]
 		f = v1
+		[d "E"]
 		Qf = v2
 	EOF
 	# exact match
-- 
2.18.0.132.g195c49a2227