Fixer cannot overwrite source file

[CommonGuy]

The appcache-manifest-fixer cannot overwrite the source file. If you attempt to do it, the source file will be empty afterwards.

I call the appcache-manifest-fixer like this:

appcache-manifest-fixer index.html -o index.html

Instead of adding the manifest-attribute, index.html is now completely empty.

[mysticatea]

Thank you for this report. And I'm sorry for my late.

appcache-manifest-fixer command was designed to use to make production code. So I did not think that the output file path is the same as the input file path.

I will add assertion check for this to avoid lost files.