sys.getfilesystemencoding return value not checked

[rjosephwright]

On HP-UX, sys.getfilesystemencoding returns None. On line 993 of genutils.py, the result of calling that function is decoded without first checking the return value.

This small patch solved it for me.

-    return ipdir.decode(sys.getfilesystemencoding())
+    fsenc = sys.getfilesystemencoding()
+    if fsenc:
+        return ipdir.decode(fsenc)
+    else:
+        return ipdir

[takluyver]

Rather than not decoding it, does it make sense to assume a default encoding of some sort, so that we're always returning a path in unicode? Is it possible to include any non-ascii characters in an HP-UX filename? And if so, what do they show up as in Python?

[minrk]

This is the same issue as #77, but closing that one since this one is more descriptive.

Instead of return ipdir it should be return ipdir.decode() to use default encoding.

Or for fewer lines:
fsenc = sys.getfilesystemencoding() or sys.getdefaultencoding()
return ipdir.decode(fsenc)

[minrk]

Marking as quickfix, as getfilesystemencoding only appears in IPython.util.path