On Mon, Nov 01, 2021 at 04:22:20PM -0400, Konstantin Ryabitsev wrote:

I think the following would be a sane check:

1. are there unicode control characters (CCs) present?
2. are there other characters from RTL languages present in the same line?

if both 1 && 2 are true, this is a legitimate use of Unicode CCs. If only 1 is
true, then it's likely worth a warning.

I implemented this solution in b4 master, so it should error out only when it
finds control characters without any "other letter" unicode character category
present in the same line (where Hebrew, Arabic, etc live). There's probably
still a way to take advantage of this, but hopefully it's a lot less trivial
now and less likely to go unnoticed by the reviewer.

The error message will point where it found the problem:

	WARNING: Message contains suspicious unicode control characters!
			 Subject: [PATCH 1/2] SPI: Add SPI driver for Sunplus SP7021
				Line: + /* ‮ } ⁦if (isAdmin)⁩ ⁦ begin admins only */
				-----------^
				Char: RIGHT-TO-LEFT OVERRIDE (0x202e)
			 If you are sure about this, rerun with the right flag to allow.

One can rerun with --allow-unicode-control-chars to override this.

-K