Use __unsafe_unretained instead of const for returning protocol arrays. Let's not break everyone's code, even if we really want to.

objc/runtime.h

@@ -231,7 +231,7 @@ objc_property_t* class_copyPropertyList(Class cls, unsigned int *outCount);
  * outCount argument is set to the number of protocols returned.  The caller is
  * responsible for freeing the returned buffer.
  */
-Protocol *const* class_copyProtocolList(Class cls, unsigned int *outCount);
+Protocol *__unsafe_unretained* class_copyProtocolList(Class cls, unsigned int *outCount);
 
 /**
  * Creates an instance of this class, allocating memory using malloc.
@@ -613,7 +613,7 @@ objc_property_t *protocol_copyPropertyList(Protocol *p, unsigned int *count);
  * number of protocols in the array being returned via the last argument.  The
  * caller is responsible for freeing this array.
  */
-Protocol *const*protocol_copyProtocolList(Protocol *p, unsigned int *count);
+Protocol *__unsafe_unretained*protocol_copyProtocolList(Protocol *p, unsigned int *count);
 
 /**
  * Returns all of the protocols that the runtime is aware of.  Note that
@@ -623,7 +623,7 @@ Protocol *const*protocol_copyProtocolList(Protocol *p, unsigned int *count);
  *
  * The caller is responsible for freeing the returned array.
  */
-Protocol *const*objc_copyProtocolList(unsigned int *outCount);
+Protocol *__unsafe_unretained*objc_copyProtocolList(unsigned int *outCount);
 /**
  * Returns the method description for the specified method within a given
  * protocol.

protocol.c

@@ -329,7 +329,7 @@ struct objc_method_description *protocol_copyMethodDescriptionList(Protocol *p,
 	return out;
 }
 
-Protocol*const* protocol_copyProtocolList(Protocol *p, unsigned int *count)
+Protocol*__unsafe_unretained* protocol_copyProtocolList(Protocol *p, unsigned int *count)
 {
 	if (NULL == p) { return NULL; }
 	*count = 0;
@@ -474,7 +474,7 @@ BOOL protocol_isEqual(Protocol *p, Protocol *other)
 	return NO;
 }
 
-Protocol*const* objc_copyProtocolList(unsigned int *outCount)
+Protocol*__unsafe_unretained* objc_copyProtocolList(unsigned int *outCount)
 {
 	unsigned int total = known_protocol_table->table_used;
 	Protocol **p = calloc(sizeof(Protocol*), known_protocol_table->table_used);

runtime.c

@@ -235,7 +235,7 @@ Method * class_copyMethodList(Class cls, unsigned int *outCount)
 	return list;
 }
 
-Protocol*const* class_copyProtocolList(Class cls, unsigned int *outCount)
+Protocol*__unsafe_unretained* class_copyProtocolList(Class cls, unsigned int *outCount)
 { 
 	CHECK_ARG(cls);
 	struct objc_protocol_list *protocolList = NULL;