Filling as a good first bug to learn workflows.

MOZ_SANDBOX is checked twice and we are in the same block
https://searchfox.org/mozilla-central/source/toolkit/xre/nsXREDirProvider.cpp#619

As the change is trivial, it is just to learn how to contribute to Firefox.

Found by http://clang.llvm.org/extra/clang-tidy/checks/readability-redundant-preprocessor.html

Tutorial to contribute:
https://firefox-source-docs.mozilla.org/tools/docs/contribute/how_to_contribute_firefox.html

Could I take this one, please?

Sure, please provide a paych

https://hg.mozilla.org/mozilla-central/rev/09770afb0f03

After taking a closer look, it appears there is another redundant #if/#endif that I missed within the same block (line 740 and 744 of what was pushed on this bug). I think this should be reopened so someone else can use it as a first bug to learn workflow.

As a note, the outer #if (MOZ_SANDBOX) (the one that doesn't need to be removed) is found on line 607 of what was pushed (follow the link from comment 4--the file may have been changed since this was pushed) and its respective #endif is on line 835.

Please open a new bug instead. They are cheap and it prevents some confusion.

Sounds good. Will do.