[Outreachy PATCH v3 2/2] gpg-interface: use string_list_split*() instead of strbuf_split*()

[Olamide Caleb Bello <belkid98@gmail.com>]

In get_default_ssh_signing_key(), the default ssh signing key is
retrieved in `key_stdout`, which is then split using
strbuf_split_max() into two tokens

The string in `key_stdout` is then split using strbuf_split_max() into
two tokens at a new line and the first token is returned as a `char *`
and not a strbuf.
This makes the function lack the use of strbuf API as no edits are
performed on the split tokens.

Replace strbuf_split_max() with string_list_split_in_place() for
simplicity

Note that strbuf_split_max() uses `2` to indicate the number of tokens
to extract from the string, while string_list_split_in_place() uses `1`
to specify the number of times the split will be done on the string,
so 1 gives 2 tokens as it is in the original instance.

string_list_split_in_place() returns the number of substrings added to the
list keys.items, so we check that at least one substring is added to the
list since we just want to return the first substring.

Signed-off-by: Olamide Caleb Bello <belkid98@gmail.com>
Reported-by: Junio Hamano <gister@pobox.com>
Helped-by: Christian Couder <christian.couder@gmail.com>
---
 gpg-interface.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/gpg-interface.c b/gpg-interface.c
index cb182f4c11..3b9d85a5ef 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -862,7 +862,7 @@ static char *get_default_ssh_signing_key(void)
 	struct child_process ssh_default_key = CHILD_PROCESS_INIT;
 	int ret = -1;
 	struct strbuf key_stdout = STRBUF_INIT, key_stderr = STRBUF_INIT;
-	struct strbuf **keys;
+	struct string_list keys = STRING_LIST_INIT_NODUP;
 	char *key_command = NULL;
 	const char **argv;
 	int n;
@@ -884,19 +884,19 @@ static char *get_default_ssh_signing_key(void)
 			   &key_stderr, 0);
 
 	if (!ret) {
-		keys = strbuf_split_max(&key_stdout, '\n', 2);
-		if (keys[0] && is_literal_ssh_key(keys[0]->buf, &literal_key)) {
+		if (string_list_split_in_place(&keys, key_stdout.buf, "\n", 1) > 0 &&
+			is_literal_ssh_key(keys.items[0].string, &literal_key)) {
 			/*
 			 * We only use `is_literal_ssh_key` here to check validity
 			 * The prefix will be stripped when the key is used.
 			 */
-			default_key = strbuf_detach(keys[0], NULL);
+			default_key = xstrdup(keys.items[0].string);
 		} else {
 			warning(_("gpg.ssh.defaultKeyCommand succeeded but returned no keys: %s %s"),
 				key_stderr.buf, key_stdout.buf);
 		}
 
-		strbuf_list_free(keys);
+		string_list_clear(&keys, 0);
 	} else {
 		warning(_("gpg.ssh.defaultKeyCommand failed: %s %s"),
 			key_stderr.buf, key_stdout.buf);
-- 
2.51.0.463.g79cf913ea9