Here are some suggestions :
Do not work directly on master branch. Create bra...

Here are some suggestions :

1. Do not work directly on master branch. Create branch/tag, Take a look at creating branches/tags Here
2. Add README.txt to module directory which would contain detailed description about module and other information if any.
3. Remove unnecessary Comment //function webform_prefill_submission_permission() from line number 36 in webform_prefill_submission.module. Also remove unnecessary code comment from line 49,66,90,100
4. Try to add more inline comments within function and also more description for all functions.

Regards,
Chintan Vyas.