Bugfix #74556 stream_socket_get_name() returns empty string

The original bug report had it returning '\0',
but with a fix to abstract name handling (6d2d0bbda7)
it now actually returns ''.

Neither of these are good, as per unix(7)
an empty socket name indicates an unbound name
and "should not be inspected".

NEWS

@@ -5,6 +5,7 @@ PHP                                                                        NEWS
 - Core:
   . Fixed bug #74658 (Undefined constants in array properties result in broken
     properties). (Laruence)
+  . Fixed misparsing of abstract unix domain socket names. (Sara)
 
 - Opcache:
   . Fixed bug #74663 (Segfault with opcache.memory_protect and
@@ -17,6 +18,9 @@ PHP                                                                        NEWS
 - FTP:
   . Fixed bug #74598 (ftp:// wrapper ignores context arg). (Sara)
 
+- Streams:
+  . Fixed bug #74556 (stream_socket_get_name() returns '\0'). (Sara)
+
 8 Jun 2017 PHP 7.0.20
 
 - Core:

ext/standard/streamsfuncs.c

@@ -314,6 +314,11 @@ PHP_FUNCTION(stream_socket_get_name)
 		RETURN_FALSE;
 	}
 
+	if (!ZSTR_LEN(name)) {
+		zend_string_release(name);
+		RETURN_FALSE;
+	}
+
 	RETVAL_STR(name);
 }
 /* }}} */

ext/standard/tests/streams/bug74556.phpt

@@ -0,0 +1,22 @@
+--TEST--
+Bug #74556 stream_socket_get_name() on unix socket returns "\0"
+--SKIPIF--
+<?php
+if (!strncasecmp(PHP_OS, 'WIN', 3)) echo "skip Unix Only";
+--FILE--
+<?php
+
+$sock = __DIR__ . '/bug74556.sock';
+$s = stream_socket_server("unix://$sock");
+$c = stream_socket_client("unix://$sock");
+
+var_dump(
+    stream_socket_get_name($s, true),
+    stream_socket_get_name($c, false)
+);
+--CLEAN--
+<?php
+unlink(__DIR__ . '/bug74556.sock');
+--EXPECT--
+bool(false)
+bool(false)