From: Antoine Pitrou <pitrou@free.fr>
Date: Tue, 2 May 2017 22:14:29 +0000 (+0200)
Subject: Backport bpo-30205 to 3.6 (#1403)
X-Git-Tag: v3.6.2rc1~183
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0c2ff0898db2db9cd9c643dfadbff11761bacf5f;p=python

Backport bpo-30205 to 3.6 (#1403)
---

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 2497e47c66..80dfc405c7 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -4660,6 +4660,10 @@ class TestUnixDomain(unittest.TestCase):
             else:
                 raise
 
+    def testUnbound(self):
+        # Issue #30205
+        self.assertIn(self.sock.getsockname(), ('', None))
+
     def testStrAddr(self):
         # Test binding to and retrieving a normal string pathname.
         path = os.path.abspath(support.TESTFN)
diff --git a/Misc/NEWS b/Misc/NEWS
index 936e2b0201..3b61543469 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -36,6 +36,8 @@ Core and Builtins
 Library
 -------
 
+- bpo-30205: Fix getsockname() for unbound AF_UNIX sockets on Linux.
+
 - bpo-30070: Fixed leaks and crashes in errors handling in the parser module.
 
 - bpo-30061: Fixed crashes in IOBase methods __next__() and readlines() when
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index f3654c97e7..42aec59ca7 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -1212,9 +1212,9 @@ makesockaddr(SOCKET_T sockfd, struct sockaddr *addr, size_t addrlen, int proto)
     {
         struct sockaddr_un *a = (struct sockaddr_un *) addr;
 #ifdef __linux__
-        if (a->sun_path[0] == 0) {  /* Linux abstract namespace */
-            addrlen -= offsetof(struct sockaddr_un, sun_path);
-            return PyBytes_FromStringAndSize(a->sun_path, addrlen);
+        size_t linuxaddrlen = addrlen - offsetof(struct sockaddr_un, sun_path);
+        if (linuxaddrlen > 0 && a->sun_path[0] == 0) {  /* Linux abstract namespace */
+            return PyBytes_FromStringAndSize(a->sun_path, linuxaddrlen);
         }
         else
 #endif /* linux */