Add sp_copy_port() function.

README

@@ -107,16 +107,32 @@ int sp_list_ports(struct sp_port ***list_ptr);
  allocate a variable of type "struct sp_port **" and pass a pointer to this to
  receive the result.
 
- The result should be freed after use by calling sp_free_port_list().
+ The result should be freed after use by calling sp_free_port_list(). If a port
+ from the list is to be used after freeing the list, it must be copied first
+ using sp_copy_port().
 
  Returns: SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation
           failure, or SP_ERR_ARG if an invalid pointer is passed. If any error
           is returned, the variable pointed to by list_ptr will be set to NULL.
           Otherwise, it will be set to point to the newly allocated array.
 
+int sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr);
+
+ Makes a new copy of a sp_port structure. The user should allocate a variable
+ of type "struct sp_port *" and pass a pointer to this to receive the result.
+
+ The copy should be freed after use by calling sp_free_port().
+
+ Returns: SP_OK on success, SP_ERR_MEM on allocation failure, or SP_ERR_ARG
+          if an invalid port or pointer is passed. If any error is returned,
+          the variable pointed to by copy_ptr will be set to NULL. Otherwise,
+          it will be set to point to the newly allocated copy.
+
 void sp_free_port_list(struct sp_port **list);
 
- Frees a port list obtained from sp_list_ports().
+ Frees a port list obtained from sp_list_ports(). This will also free all
+ the sp_port structures referred to from the list; any that are to be retained
+ must be copied first using sp_copy_port().
 
 Opening and closing ports
 -------------------------

libserialport.h

@@ -82,6 +82,7 @@ enum {
 int sp_get_port_by_name(const char *portname, struct sp_port **port_ptr);
 void sp_free_port(struct sp_port *port);
 int sp_list_ports(struct sp_port ***list_ptr);
+int sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr);
 void sp_free_port_list(struct sp_port **ports);
 int sp_open(struct sp_port *port, int flags);
 int sp_close(struct sp_port *port);

serialport.c

@@ -50,6 +50,9 @@ int sp_get_port_by_name(const char *portname, struct sp_port **port_ptr)
 	struct sp_port *port;
 	int len;
 
+	if (!port_ptr)
+		return SP_ERR_ARG;
+
 	*port_ptr = NULL;
 
 	if (!portname)
@@ -73,6 +76,19 @@ int sp_get_port_by_name(const char *portname, struct sp_port **port_ptr)
 	return SP_OK;
 }
 
+int sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr)
+{
+	if (!copy_ptr)
+		return SP_ERR_ARG;
+
+	*copy_ptr = NULL;
+
+	if (!port || !port->name)
+		return SP_ERR_ARG;
+
+	return sp_get_port_by_name(port->name, copy_ptr);
+}
+
 void sp_free_port(struct sp_port *port)
 {
 	if (!port)