Merge PR #999 (core.packet: add clone_to_memory) into max-next

src/README.md

@@ -387,7 +387,7 @@ or equal to `length` of *packet*.
 
 — Function **packet.shiftright** *packet*, *length*
 
-Move *packet* payload to the right by *length* bytes, growing *packet* by
+Moves *packet* payload to the right by *length* bytes, growing *packet* by
 *length*. The sum of *length* and `length` of *packet* must be less than or
 equal to `packet.max_payload`.
 
@@ -399,6 +399,10 @@ Allocate packet and fill it with *length* bytes from *pointer*.
 
 Allocate packet and fill it with the contents of *string*.
 
+— Function **packet.clone_to_memory* *pointer* *packet*
+
+Creates an exact copy of at memory pointed to by *pointer*. *Pointer* must
+point to a `packet.packet_t`.
 
 ## Memory (core.memory)
 

src/core/packet.lua

@@ -71,12 +71,17 @@ function new_packet ()
    return p
 end
 
+-- Create an exact copy of srcp at memory pointed to by dstp.
+function clone_to_memory(dstp, srcp)
+   ffi.copy(dstp, srcp, srcp.length)
+   dstp.length = srcp.length
+   return dstp
+end
+
 -- Create an exact copy of a packet.
 function clone (p)
    local p2 = allocate()
-   ffi.copy(p2, p, p.length)
-   p2.length = p.length
-   return p2
+   return clone_to_memory(p2, p)
 end
 
 -- Append data to the end of a packet.