From: Mark Wooding <mdw@distorted.org.uk>
Date: Fri, 25 Apr 2014 21:37:17 +0000 (+0100)
Subject: Merge branch 'master' of git.distorted.org.uk:~mdw/publish/public-git/zone
X-Git-Url: https://git.distorted.org.uk/~mdw/zone/commitdiff_plain/804882ca1c12315b7943c6f71f7bb43866a7a301?hp=fffebf35970307ed798db324a9399e31c241b02d

Merge branch 'master' of git.distorted.org.uk:~mdw/publish/public-git/zone

* 'master' of git.distorted.org.uk:~mdw/publish/public-git/zone:
  addr-family-ipv6.lisp (ipaddr-string): Ignore trivial runs of zeros.
  addr-family-ipv6.lisp (ipaddr-string): Use IPv4 notation if appropriate.
  addr-family-ipv6.lisp (ipaddr-string): Upend the conditional.
---

diff --git a/addr-family-ipv6.lisp b/addr-family-ipv6.lisp
index 3c37907..5ed014e 100644
--- a/addr-family-ipv6.lisp
+++ b/addr-family-ipv6.lisp
@@ -157,7 +157,8 @@
 
     ;; Third step: output the two parts of the address either side of the
     ;; longest zero run.  If there are no zero words in the address, just
-    ;; write the whole thing.
+    ;; write the whole thing.  There's a special case here for the
+    ;; IPv6-mapped IPv4 address space ::ffff:0.0.0.0/96.
     (with-output-to-string (out)
       (flet ((chunk (start end)
 	       (when (< start end)
@@ -167,12 +168,23 @@
 		     (incf i)
 		     (when (>= i end) (return))
 		     (write-char #\: out))))))
-	(cond (best-start
+	(cond ((< best-length 2)
+	       (chunk 0 8))
+	      ((and (= best-start 0)
+		    (or (and (= best-length 5)
+			     (= (aref words 5) #xffff))
+			(= best-length 6)))
+	       (let ((v4addr (make-instance 'ip4addr
+					    :addr (ldb (byte 32 0) addr))))
+		 (write-string "::" out)
+		 (when (= best-length 5)
+		   (chunk 5 6)
+		   (write-char #\: out))
+		 (write-string (ipaddr-string v4addr) out)))
+	      (t
 	       (chunk 0 best-start)
 	       (write-string "::" out)
-	       (chunk (+ best-start best-length) 8))
-	      (t
-	       (chunk 0 8)))))))
+	       (chunk (+ best-start best-length) 8)))))))
 
 ;;;--------------------------------------------------------------------------
 ;;; IPv6 networks.