Merge "Fix `adb install` on very old Android releases."

}

int delete_device_file(const std::string& filename) {

    std::string cmd = "rm -f " + escape_arg(filename);

    return send_shell_command(cmd);

    // http://b/17339227 "Sideloading a Readonly File Results in a Prompt to

    // Delete" caused us to add `-f` here, to avoid the equivalent of the `-i`

    // prompt that you get from BSD rm (used in Android 5) if you have a

    // non-writable file and stdin is a tty (which is true for old versions of

    // adbd).

    //

    // Unfortunately, `rm -f` requires Android 4.3, so that workaround broke

    // earlier Android releases. This was reported as http://b/37704384 "adb

    // install -r passes invalid argument to rm on Android 4.1" and

    // http://b/37035817 "ADB Fails: rm failed for -f, No such file or

    // directory".

    //

    // Testing on a variety of devices and emulators shows that redirecting

    // stdin is sufficient to avoid the pseudo-`-i`, and works on toolbox,

    // BSD, and toybox versions of rm.

    return send_shell_command("rm " + escape_arg(filename) + " </dev/null");

}