(isc_relocate_fd): New function.

src/libraries/libisc-new/src/intern.h

@@ -98,6 +98,16 @@ extern void
 isc_setabortfn(void (*abortfn)(const char  * msg));
 
 
+/*
+ * Move a file descriptor FD the first unused file descriptor higher
+ * than LIMIT.  Return the new file descriptor.  Close FD.
+ *
+ * On failure, the old FD will be returned, and errno will be set.
+ *
+ * Do nothing (and return FD) if LIMIT is 0.
+ */
+extern int
+isc_relocate_fd(int fd, int limit);
 
 
 #define ISC_XNEW(var)   (var = isc_malloc(sizeof(*var)))