From a6628709c50a497288df9fe2a7d19db089ca4e05 Mon Sep 17 00:00:00 2001
From: RumovZ <gp5glkw78@relay.firefox.com>
Date: Sun, 15 Nov 2020 14:22:16 +0100
Subject: [PATCH] Annotate RegEx for invalid-escape check

---
 rslib/src/search/parser.rs | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/rslib/src/search/parser.rs b/rslib/src/search/parser.rs
index 6c3a35f07..a9df06dd0 100644
--- a/rslib/src/search/parser.rs
+++ b/rslib/src/search/parser.rs
@@ -447,7 +447,15 @@ fn unescape_quotes(s: &str) -> Cow<str> {
 fn is_invalid_escape(txt: &str) -> bool {
     // odd number of \s not followed by an escapable character
     lazy_static! {
-        static ref RE: Regex = Regex::new(r#"(^|[^\\])(\\\\)*\\([^\\":*_()]|$)"#).unwrap();
+        static ref RE: Regex = Regex::new(
+            r#"(?x)
+            (?:^|[^\\])         # not a backslash
+            (?:\\\\)*           # even number of backslashes
+            \\                  # single backslash
+            (?:[^\\":*_()]|$)   # anything but an escapable char
+            "#
+        )
+        .unwrap();
     }
 
     RE.is_match(txt)