Work-around HHVM < 3.19 returning ":" for unknown Unix socket addresses

Author: clue

src/Connection.php

@@ -146,11 +146,17 @@ private function parseAddress($address)
         }
 
         if ($this->unix) {
-            // unknown addresses should not return a NULL-byte string
-            if ($address === "\x00") {
+            // work around unknown addresses should return null value: https://3v4l.org/5C1lo
+            // PHP uses "\0" string and HHVM < 3.19 uses ":" string
+            if ($address === "\x00" || $address === ':') {
                 return null;
             }
 
+            // remove trailing colon from address for HHVM < 3.19
+            if (substr($address, -1) === ':') {
+                $address = (string)substr($address, 0, -1);
+            }
+
             return 'unix://' . $address;
         }