Coverity: Fix 1583538, 1583565 and 1583573

For the test suite, treat these tests as using the public API so locking
is handled by the underlying libcoap.

The only exception is for coap_delete_node() which is an internal function
and expects context to be locked on entry.

tests/test_common.h.in

@@ -8,5 +8,8 @@
  * README for terms of use.
  */
 
+/* We need to treat these tests as being an user application */
+#define COAP_THREAD_IGNORE_LOCKED_MAPPING
+
 #include "coap@LIBCOAP_API_VERSION@/coap_internal.h"
 

tests/test_oscore.c

@@ -1029,10 +1029,6 @@ static int
 t_oscore_tests_create(void) {
   ctx = coap_new_context(NULL);
 
-  if (ctx != NULL) {
-    coap_lock_lock(ctx, return 1);
-  }
-
   return (ctx == NULL);
 }
 

tests/test_sendqueue.c

@@ -284,7 +284,6 @@ t_sendqueue_tests_create(void) {
   addr.addr.sin6.sin6_port = htons(COAP_DEFAULT_PORT);
 
   ctx = coap_new_context(&addr);
-  coap_lock_lock(ctx, return 1);
 
   addr.addr.sin6.sin6_addr = in6addr_loopback;
   session = coap_new_client_session(ctx, NULL, &addr, COAP_PROTO_UDP);
@@ -308,7 +307,10 @@ t_sendqueue_tests_create(void) {
     /* destroy all test nodes and set entry to zero */
     for (n = 0; n < sizeof(node)/sizeof(coap_queue_t *); n++) {
       if (node[n]) {
+        /* As coap_delete_node() is not in the Public API, need to lock */
+        coap_lock_lock(ctx, continue);
         coap_delete_node(node[n]);
+        coap_lock_unlock(ctx);
         node[n] = NULL;
       }
     }
@@ -324,7 +326,10 @@ t_sendqueue_tests_remove(void) {
   size_t n;
   for (n = 0; n < sizeof(node)/sizeof(coap_queue_t *); n++) {
     if (node[n]) {
+      /* As coap_delete_node() is not in the Public API, need to lock */
+      coap_lock_lock(ctx, continue);
       coap_delete_node(node[n]);
+      coap_lock_unlock(ctx);
       node[n] = NULL;
     }
   }

tests/test_session.c

@@ -182,7 +182,6 @@ t_session_tests_create(void) {
   ctx = coap_new_context(&addr);
 
   if (ctx != NULL) {
-    coap_lock_lock(ctx, return 1);
     addr.addr.sin6.sin6_addr = in6addr_loopback;
     session = coap_new_client_session(ctx, NULL, &addr, COAP_PROTO_UDP);
   }

tests/test_wellknown.c

@@ -200,7 +200,6 @@ t_wkc_tests_create(void) {
   addr.addr.sin6.sin6_port = htons(COAP_DEFAULT_PORT);
 
   ctx = coap_new_context(&addr);
-  coap_lock_lock(ctx, return 1);
 
   addr.addr.sin6.sin6_addr = in6addr_loopback;
   session = coap_new_client_session(ctx, NULL, &addr, COAP_PROTO_UDP);