diff options
| -rw-r--r-- | library/core/src/str/pattern.rs | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/library/core/src/str/pattern.rs b/library/core/src/str/pattern.rs index 508c522e71a..55ac1aa765c 100644 --- a/library/core/src/str/pattern.rs +++ b/library/core/src/str/pattern.rs @@ -928,6 +928,8 @@ struct EmptyNeedle { end: usize, is_match_fw: bool, is_match_bw: bool, + // Needed in case of an empty haystack, see #85462 + is_finished: bool, } impl<'a, 'b> StrSearcher<'a, 'b> { @@ -941,6 +943,7 @@ impl<'a, 'b> StrSearcher<'a, 'b> { end: haystack.len(), is_match_fw: true, is_match_bw: true, + is_finished: false, }), } } else { @@ -966,13 +969,19 @@ unsafe impl<'a, 'b> Searcher<'a> for StrSearcher<'a, 'b> { fn next(&mut self) -> SearchStep { match self.searcher { StrSearcherImpl::Empty(ref mut searcher) => { + if searcher.is_finished { + return SearchStep::Done; + } // empty needle rejects every char and matches every empty string between them let is_match = searcher.is_match_fw; searcher.is_match_fw = !searcher.is_match_fw; let pos = searcher.position; match self.haystack[pos..].chars().next() { _ if is_match => SearchStep::Match(pos, pos), - None => SearchStep::Done, + None => { + searcher.is_finished = true; + SearchStep::Done + } Some(ch) => { searcher.position += ch.len_utf8(); SearchStep::Reject(pos, searcher.position) @@ -1045,12 +1054,18 @@ unsafe impl<'a, 'b> ReverseSearcher<'a> for StrSearcher<'a, 'b> { fn next_back(&mut self) -> SearchStep { match self.searcher { StrSearcherImpl::Empty(ref mut searcher) => { + if searcher.is_finished { + return SearchStep::Done; + } let is_match = searcher.is_match_bw; searcher.is_match_bw = !searcher.is_match_bw; let end = searcher.end; match self.haystack[..end].chars().next_back() { _ if is_match => SearchStep::Match(end, end), - None => SearchStep::Done, + None => { + searcher.is_finished = true; + SearchStep::Done + } Some(ch) => { searcher.end -= ch.len_utf8(); SearchStep::Reject(searcher.end, end) |