coap_threadsafe.c: Fix NPE in coap_delete_resource()

include/coap3/coap_mutex_internal.h

@@ -337,7 +337,7 @@ int coap_lock_lock_func(coap_lock_t *lock);
     } \
   } while (0)
 
-#define coap_lock_check_locked(s)
+#define coap_lock_check_locked(s) {}
 
 # endif /* ! COAP_THREAD_RECURSIVE_CHECK */
 
@@ -352,7 +352,7 @@ typedef coap_mutex_t coap_lock_t;
 #define coap_lock_unlock(s)
 #define coap_lock_init(s)
 #define coap_lock_being_freed(s,failed)
-#define coap_lock_check_locked(s)
+#define coap_lock_check_locked(s) {}
 #define coap_lock_callback(s,func) func
 #define coap_lock_callback_ret(r,s,func) ret = func
 #define coap_lock_invert(s,func,f) func

src/coap_resource.c

@@ -555,8 +555,10 @@ coap_delete_resource(coap_context_t *context, coap_resource_t *resource) {
   if (!resource)
     return 0;
 
-  coap_lock_check_locked(context);
   context = resource->context;
+  if (context) {
+    coap_lock_check_locked(context);
+  }
 
   if (resource->is_unknown) {
     if (context && context->unknown_resource == resource) {

src/coap_threadsafe.c

@@ -294,9 +294,17 @@ int
 coap_delete_resource(coap_context_t *context, coap_resource_t *resource) {
   int ret;
 
-  coap_lock_lock(context, return 0);
-  ret = coap_delete_resource_locked(context, resource);
-  coap_lock_unlock(context);
+  if (!resource)
+    return 0;
+
+  context = resource->context;
+  if (context) {
+    coap_lock_lock(context, return 0);
+    ret = coap_delete_resource_locked(context, resource);
+    coap_lock_unlock(context);
+  } else {
+    ret = coap_delete_resource_locked(context, resource);
+  }
   return ret;
 }
 
@@ -485,6 +493,8 @@ coap_delete_oscore_recipient(coap_context_t *context,
                              coap_bin_const_t *recipient_id) {
   int ret;
 
+  if (!context || !recipient_id)
+    return 0;
   coap_lock_lock(context, return 0);
   ret = coap_delete_oscore_recipient_locked(context, recipient_id);
   coap_lock_unlock(context);