From: Bob Halley <halley@dnspython.org>
Date: Wed, 18 Jun 2014 23:13:39 +0000 (-0700)
Subject: Allow empty APL RR.
X-Git-Tag: v1.12.0~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b2dac7593f03793f7695a8e137d26a0a25140b44;p=thirdparty%2Fdnspython.git

Allow empty APL RR.
---

diff --git a/ChangeLog b/ChangeLog
index 9ee3bf73..fcf2f821 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-06-18  Bob Halley  <halley@dnspython.org>
+
+    * dns/rdtypes/IN/APL.py: The APL from_wire() method did not accept an
+      rdata length of 0 as valid.  Thanks to salzmdan for reporting the
+      problem.
+
 2014-05-31  Bob Halley  <halley@dnspython.org>
 
 	* dns/ipv6.py: Add is_mapped()
diff --git a/dns/rdtypes/IN/APL.py b/dns/rdtypes/IN/APL.py
index 260fd6f3..59da75b9 100644
--- a/dns/rdtypes/IN/APL.py
+++ b/dns/rdtypes/IN/APL.py
@@ -118,6 +118,8 @@ class APL(dns.rdata.Rdata):
     def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
         items = []
         while 1:
+            if rdlen == 0:
+                break
             if rdlen < 4:
                 raise dns.exception.FormError
             header = struct.unpack('!HBB', wire[current : current + 4])
@@ -151,8 +153,6 @@ class APL(dns.rdata.Rdata):
             rdlen -= afdlen
             item = APLItem(header[0], negation, address, header[1])
             items.append(item)
-            if rdlen == 0:
-                break
         return cls(rdclass, rdtype, items)
 
     from_wire = classmethod(from_wire)
diff --git a/tests/test_bugs.py b/tests/test_bugs.py
index 312ec3ef..cee87575 100644
--- a/tests/test_bugs.py
+++ b/tests/test_bugs.py
@@ -45,5 +45,12 @@ class BugsTestCase(unittest.TestCase):
                                     "1 0 100 ABCD SCBCQHKU35969L2A68P3AD59LHF30715")
         self.failUnless(rdata.windows == [])
 
+    def test_zero_size_APL(self):
+        rdata = dns.rdata.from_text(dns.rdataclass.IN, dns.rdatatype.APL,
+                                    "")
+        rdata2 = dns.rdata.from_wire(dns.rdataclass.IN, dns.rdatatype.APL,
+                                     "", 0, 0)
+        self.failUnless(rdata == rdata2)
+
 if __name__ == '__main__':
     unittest.main()