diff -Nru apt-0.9.6ubuntu1/cmdline/apt-key apt-0.9.6ubuntu2/cmdline/apt-key
--- apt-0.9.6ubuntu1/cmdline/apt-key	2012-06-11 17:00:56.000000000 -0500
+++ apt-0.9.6ubuntu2/cmdline/apt-key	2012-06-14 11:51:01.000000000 -0500
@@ -50,18 +50,20 @@
     #   all keys that are exported must have a valid signature
     #   from a key in the $distro-master-keyring
     add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^pub | cut -d: -f5`
+    all_add_keys=`$GPG_CMD --keyring $ADD_KEYRING --with-colons --list-keys | grep ^[ps]ub | cut -d: -f5`
     master_keys=`$GPG_CMD --keyring $MASTER --with-colons --list-keys | grep ^pub | cut -d: -f5`
-    
-    for add_key in $add_keys; do
 
-        # ensure there are no colisions LP: #857472
+    # ensure there are no colisions LP: #857472
+    for all_add_key in $all_add_keys; do
 	for master_key in $master_keys; do
-            if [ "$add_key" = "$master_key" ]; then
-                echo >&2 "Keyid collision for '$add_key' detected, operation aborted"
+            if [ "$all_add_key" = "$master_key" ]; then
+                echo >&2 "Keyid collision for '$all_add_key' detected, operation aborted"
                 return 1
             fi
         done
-
+    done
+    
+    for add_key in $add_keys; do
         # export the add keyring one-by-one
         rm -f $TMP_KEYRING
         $GPG_CMD --keyring $ADD_KEYRING --output $TMP_KEYRING --export $add_key 
diff -Nru apt-0.9.6ubuntu1/debian/changelog apt-0.9.6ubuntu2/debian/changelog
Binary files /tmp/qaFS9FADpq/apt-0.9.6ubuntu1/test/integration/exploid-keyring-with-dupe-subkeys.pub and /tmp/h2XtD7JdKl/apt-0.9.6ubuntu2/test/integration/exploid-keyring-with-dupe-subkeys.pub differ
diff -Nru apt-0.9.6ubuntu1/test/integration/test-apt-key-net-update apt-0.9.6ubuntu2/test/integration/test-apt-key-net-update
--- apt-0.9.6ubuntu1/test/integration/test-apt-key-net-update	2012-03-31 15:45:56.000000000 -0500
+++ apt-0.9.6ubuntu2/test/integration/test-apt-key-net-update	2012-06-14 11:51:01.000000000 -0500
@@ -49,6 +49,26 @@
     msgpass
 fi
 
+
+# test another possible attack vector using subkeys (LP: #1013128)
+msgtest "add_keys_with_verify_against_master_keyring with subkey attack"
+ADD_KEYRING=./keys/exploid-keyring-with-dupe-subkeys.pub
+if add_keys_with_verify_against_master_keyring $ADD_KEYRING $MASTER_KEYRING; then
+    msgfail
+else
+    msgpass
+fi
+
+# ensure the keyring is still empty
+gpg_out=$($GPG --list-keys)
+msgtest "Test if keyring is empty"
+if [ -n "" ]; then
+    msgfail
+else
+    msgpass
+fi
+
+
 # test good keyring and ensure we get no errors
 ADD_KEYRING=/usr/share/keyrings/ubuntu-archive-keyring.gpg
 if add_keys_with_verify_against_master_keyring $ADD_KEYRING $MASTER_KEYRING; then
@@ -66,3 +86,4 @@
 pub   1024D/FBB75451 2004-12-30
 uid                  Ubuntu CD Image Automatic Signing Key <cdimage@ubuntu.com>
 ' $GPG --list-keys
+