What version of ripgrep are you using?

ripgrep 13.0.0
-SIMD -AVX (compiled)
+SIMD +AVX (runtime)

How did you install ripgrep?

Homebrew

What operating system are you using ripgrep on?

macOS Big Sur, Intel.

Describe your bug.

Ripgrep segfaults when using -w option with an empty string.

What are the steps to reproduce the behavior?

1. Create a new directory
2. Download https://raw.githubusercontent.com/neovim/neovim/master/README.md
3. rg -w ''

(Happens in most directories with a wide variety of contents, but haven't come up with a minimal example by manually adding content to an empty file.)

What is the actual behavior?

thread '<unnamed>' panicked at 'assertion failed: self.start <= end', /private/tmp/ripgrep-20210612-52810-yuhb53/ripgrep-13.0.0/crates/matcher/src/lib.rs:131:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Any', crates/ignore/src/walk.rs:1302:31

followed by a hang.

What is the expected behavior?

Ripgrep shouldn't segfault and ignore the -w option. (Which I believe version 12 did, which doesn't segfault on this command.)

Removing the pointless -w option works as expected, but I thought I'd report it anyway in case this is a symptom of a deeper issue that may have more serious consequences.