SuFile.isDirectory() can throw NoShellException (and shouldn't)

[Fox2Code]

Due to SuFile.isDirectory() call SuFile.cmdBool() call SuFile.getShell() call Shell.getShell() call MainShell.get() call BuilderImpl.build() that can throw NoShellException and can causes crashes as it is a common assumption that File.isDirectory() does not throw any errors.

This is very obscure effect was discovered by someone using my app that use libsu.

[vvb2060]

I think this is expected behavior and it is the developer's responsibility to check that the shell is valid before using it.

[Fox2Code]

I personally disagree that isDirectory() should throw NoShellException because SuFile extends File, when this issue crashed my app on someone device, I had no idea and it was a existing behavior for me, so this was very unexpected for me.

I already did my best do avoid calling SuFile when root does not exists or is not available, and this "behavior" was really unexpected, so I think it's definitely a flaw of the library because the goal of a library is to help developers make programs.

But this is mainly a mater of opinion, so I understand the disagreement.

[topjohnwu]

Well, SuFile is backed by a shell; if you have no shell available, how does it operate? If you are really concerned about this, you should move over to use the nio module.

[Fox2Code]

Well, I reported this because SuFile crashed despite my app checking for root access.