pediapress/mwlib — comment on commit 87b7eb3345ad33a2639f2d88bc5261365102f160
File:  line 0
By schmir:

lxml warnings??

by raising a TypeError before?

```
File "/home/ralf/code/mwlib/mathutils.py", line 138, in renderMath
if not len(result) and output_mode == 'png':
TypeError: object of type 'NoneType' has no len()
```