Fix compilation warnings/errors and static analysis issues

A deadcode issue is fixed by changing an AND to OR so that it is
actually possible to hit the condition. One change of palloc to
palloc0 to potentially prevent a Valgrind issue.

src/bgw/job.c

@@ -58,7 +58,9 @@ bgw_job_start(BgwJob *job)
 static JobType
 get_job_type_from_name(Name job_type_name)
 {
-	for (int i = 0; i < _MAX_JOB_TYPE; i++)
+	int			i;
+
+	for (i = 0; i < _MAX_JOB_TYPE; i++)
 		if (namestrcmp(job_type_name, job_type_names[i]) == 0)
 			return i;
 	return JOB_TYPE_UNKNOWN;

src/bgw/scheduler.c

@@ -168,7 +168,9 @@ assert_that_worker_has_stopped(ScheduledBgwJob *sjob)
 static void
 scheduled_bgw_job_transition_state_to(ScheduledBgwJob *sjob, JobState new_state)
 {
+#if USE_ASSERT_CHECKING
 	JobState	prev_state = sjob->state;
+#endif
 
 	BgwJobStat *job_stat;
 

src/net/conn_plain.c

@@ -28,7 +28,7 @@ plain_connect(Connection *conn, const char *host, const char *servname, int port
 	};
 	int			ret;
 
-	if (NULL == servname && port <= 0 && port > MAX_PORT)
+	if (NULL == servname && (port <= 0 || port > MAX_PORT))
 		return -1;
 
 	/* Explicit port given. Use it instead of servname */

src/telemetry/uuid.c

@@ -21,7 +21,7 @@ uuid_create(void)
 	 * PG9.6 doesn't expose the internals of pg_uuid_t, so we just treat it as
 	 * a byte array
 	 */
-	unsigned char *gen_uuid = palloc(UUID_LEN);
+	unsigned char *gen_uuid = palloc0(UUID_LEN);
 	bool		rand_success = false;
 
 #if PG10

test/src/bgw/scheduler_mock.c

@@ -211,7 +211,9 @@ test_job_3_long()
 static TestJobType
 get_test_job_type_from_name(Name job_type_name)
 {
-	for (int i = 0; i < _MAX_TEST_JOB_TYPE; i++)
+	int			i;
+
+	for (i = 0; i < _MAX_TEST_JOB_TYPE; i++)
 	{
 		if (namestrcmp(job_type_name, test_job_type_names[i]) == 0)
 			return i;