socket: parse message queue size as IEC size

Allow MessageQueueMessageSize= to accept IEC size suffixes in socket unit files.
Support the same syntax for transient property assignments.
Keep MessageQueueMaxMessages= as a plain message count.

src/test/test-bus-unit-util.c

@@ -848,7 +848,6 @@ TEST(socket_properties) {
 
                         /* 64-bit integer properties */
                         "MessageQueueMaxMessages=10",
-                        "MessageQueueMessageSize=8192",
 
                         /* Timespan properties */
                         "TimeoutSec=90s",
@@ -871,6 +870,7 @@ TEST(socket_properties) {
                         "ReceiveBuffer=512K",
                         "SendBuffer=1.M",  // TODO: should this accept multiple components?
                         "PipeSize=512K",
+                        "MessageQueueMessageSize=8K",
 
                         /* Exec command properties */
                         "ExecStartPre=true",

src/test/test-conf-parser.c

@@ -41,6 +41,14 @@ static void test_config_parse_iec_size_one(const char *rvalue, size_t expected)
         ASSERT_EQ(expected, iec_size);
 }
 
+static void test_config_parse_iec_size_long_one(const char *rvalue, long expected) {
+        long iec_size = 0;
+
+        ASSERT_OK(config_parse_iec_size_long(
+                          "unit", "filename", 1, "section", 1, "lvalue", 0, rvalue, &iec_size, NULL));
+        ASSERT_EQ(expected, iec_size);
+}
+
 static void test_config_parse_si_uint64_one(const char *rvalue, uint64_t expected) {
         uint64_t si_uint64 = 0;
 
@@ -135,6 +143,19 @@ TEST(config_parse_iec_size) {
         test_config_parse_iec_size_one("garbage", 0);
 }
 
+TEST(config_parse_iec_size_long) {
+        test_config_parse_iec_size_long_one("1024", 1024);
+        test_config_parse_iec_size_long_one("2K", 2048);
+        test_config_parse_iec_size_long_one("10M", 10 * 1024 * 1024);
+        test_config_parse_iec_size_long_one("1G", 1L * 1024 * 1024 * 1024);
+        test_config_parse_iec_size_long_one("0G", 0);
+        test_config_parse_iec_size_long_one("0", 0);
+
+        test_config_parse_iec_size_long_one("-982", 0);
+        test_config_parse_iec_size_long_one("49874444198739873000000G", 0);
+        test_config_parse_iec_size_long_one("garbage", 0);
+}
+
 TEST(config_parse_si_uint64) {
         test_config_parse_si_uint64_one("1024", 1024);
         test_config_parse_si_uint64_one("2K", 2000);