upload-pack: fix error message typo

Fix a typo in an error message.

Also, this line was introduced in 3145ea9 ("upload-pack: introduce
fetch server command", 2018-03-15), which did not contain a test for the
case which causes this error to be printed, so introduce a test.

Signed-off-by: Jonathan Tan <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: jonathantanmy

t/t5701-git-serve.sh

@@ -173,4 +173,18 @@ test_expect_success 'symrefs parameter' '
 	test_cmp actual expect
 '
 
+test_expect_success 'unexpected lines are not allowed in fetch request' '
+	git init server &&
+
+	test-pkt-line pack >in <<-EOF &&
+	command=fetch
+	0001
+	this-is-not-a-command
+	0000
+	EOF
+
+	test_must_fail git -C server serve --stateless-rpc <in >/dev/null 2>err &&
+	grep "unexpected line: .this-is-not-a-command." err
+'
+
 test_done

upload-pack.c

@@ -1252,7 +1252,7 @@ static void process_args(struct packet_reader *request,
 		}
 
 		/* ignore unknown lines maybe? */
-		die("unexpect line: '%s'", arg);
+		die("unexpected line: '%s'", arg);
 	}
 }