flock system call is not available on Solaris but it can be 

replaced by calling fcntl. This patch will be sent upstream

after being reworked into a format that will be acceptable.

--- wget-1.17.1/src/hsts.c.orig	Tue Jan 12 09:14:54 2016

+++ wget-1.17.1/src/hsts.c	Tue Jan 12 09:16:55 2016

@@ -49,6 +49,7 @@

 #include <string.h>

 #include <stdio.h>

 #include <sys/file.h>

+#include <fcntl.h>

 struct hsts_store {

   struct hash_table *table;

@@ -498,6 +499,7 @@

   struct_stat st;

   FILE *fp = NULL;

   int fd = 0;

+  struct flock lock_data;

   if (filename && hash_table_count (store->table) > 0)

     {

@@ -506,7 +508,11 @@

         {

           /* Lock the file to avoid potential race conditions */

           fd = fileno (fp);

-          flock (fd, LOCK_EX);

+          lock_data.l_start = 0;

+          lock_data.l_len = 0;

+          lock_data.l_whence = SEEK_SET;

+          lock_data.l_type = F_WRLCK;

+          fcntl(fd, F_SETLKW, &lock_data);

           /* If the file has changed, merge the changes with our in-memory data

              before dumping them to the file.