#717: ignore everything after the first occurrence of '\x00' instead …

…of replacing '\x00' for the whole string

psutil/_compat.py

@@ -17,6 +17,7 @@
     long = int
     xrange = range
     unicode = str
+    basestring = str
 
     def u(s):
         return s
@@ -27,6 +28,7 @@ def b(s):
     long = long
     xrange = xrange
     unicode = unicode
+    basestring = basestring
 
     def u(s):
         return unicode(s, "unicode_escape")

psutil/_pslinux.py

@@ -32,6 +32,7 @@
 from ._common import supports_ipv6
 from ._common import usage_percent
 from ._compat import b
+from ._compat import basestring
 from ._compat import long
 from ._compat import PY3
 
@@ -152,14 +153,19 @@ def get_procfs_path():
 
 def readlink(path):
     """Wrapper around os.readlink()."""
+    assert isinstance(path, basestring), path
     path = os.readlink(path)
-    # readlink() might return paths containing null bytes causing
-    # problems when used with other fs-related functions (os.*,
-    # open(), ...), see:
+    # readlink() might return paths containing null bytes ('\x00')
+    # resulting in "TypeError: must be encoded string without NULL
+    # bytes, not str" errors when the string is passed to other
+    # fs-related functions (os.*, open(), ...).
+    # Apparently everything after '\x00' is garbage (we can have
+    # ' (deleted)', 'new' and possibly others), see:
     # https://github.com/giampaolo/psutil/issues/717
-    path = path.replace('\x00', '')
+    path = path.split('\x00')[0]
     # Certain paths have ' (deleted)' appended. Usually this is
-    # bogus as the file actually exists.
+    # bogus as the file actually exists. Even if it doesn't we
+    # don't care.
     if path.endswith(' (deleted)') and not path_exists_strict(path):
         path = path[:-10]
     return path