From 2b863784d39b17141a02b8bc18cb7c5f55e2d9e6 Mon Sep 17 00:00:00 2001 From: Michael Sloan Date: Thu, 11 Sep 2025 15:26:03 -0600 Subject: [PATCH] Cherry pick 38015 to v0.203.x "Fix panics from unicode slicing in license detection" (#38017) Release Notes: - N/A --- crates/zeta/src/license_detection.rs | 40 +++++++++++++++++++++++----- 1 file changed, 33 insertions(+), 7 deletions(-) diff --git a/crates/zeta/src/license_detection.rs b/crates/zeta/src/license_detection.rs index 5f207a44e8bd2028e6a2b416e978f101cfe5bd57..cef4e6a0cdc4c84286c67c8ce890dd96e811db4b 100644 --- a/crates/zeta/src/license_detection.rs +++ b/crates/zeta/src/license_detection.rs @@ -202,22 +202,48 @@ fn check_pattern(pattern: &[PatternPart], input: &str) -> bool { match_any_chars.end += part.match_any_chars.end; continue; } - let search_range_start = input_ix.saturating_sub(match_any_chars.end + part.text.len()); - let search_range_end = input_ix.saturating_sub(match_any_chars.start); - let found_ix = &input[search_range_start..search_range_end].rfind(&part.text); + + let search_range_end = n_chars_before_offset(match_any_chars.start, input_ix, input); + let search_range_start = n_chars_before_offset( + match_any_chars.len() + part.text.len(), + search_range_end, + input, + ); + let found_ix = input[search_range_start..search_range_end].rfind(&part.text); + if let Some(found_ix) = found_ix { input_ix = search_range_start + found_ix; match_any_chars = part.match_any_chars.clone(); } else if !part.optional { log::trace!( - "Failed to match pattern `...{}` against input `...{}`", - &part.text[part.text.len().saturating_sub(128)..], - &input[input_ix.saturating_sub(128)..] + "Failed to match pattern\n`...{}`\nagainst input\n`...{}`", + &part.text[n_chars_before_offset(128, part.text.len(), &part.text)..], + &input[n_chars_before_offset(128, search_range_end, input)..search_range_end], ); return false; } } - match_any_chars.contains(&input_ix) + is_char_count_within_range(&input[..input_ix], match_any_chars) +} + +fn n_chars_before_offset(char_count: usize, offset: usize, string: &str) -> usize { + if char_count == 0 { + return offset; + } + string[..offset] + .char_indices() + .nth_back(char_count.saturating_sub(1)) + .map_or(0, |(byte_ix, _)| byte_ix) +} + +fn is_char_count_within_range(string: &str, char_count_range: Range) -> bool { + if string.len() >= char_count_range.start * 4 && string.len() < char_count_range.end { + return true; + } + if string.len() < char_count_range.start || string.len() >= char_count_range.end * 4 { + return false; + } + char_count_range.contains(&string.chars().count()) } /// Canonicalizes license text by removing all non-alphanumeric characters, lowercasing, and turning