Skip to content

Backreferences do not guarantee forward progress #598

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Aug 15, 2022
Merged

Backreferences do not guarantee forward progress #598

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions Sources/_StringProcessing/ByteCodeGen.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1019,6 +1019,8 @@ extension DSLTree.Node {
case .atom(let atom):
switch atom {
case .changeMatchingOptions, .assertion: return false
// Captures may be nil so backreferences may be zero length matches
case .backreference: return false
default: return true
}
case .trivia, .empty:
Expand Down
4 changes: 4 additions & 0 deletions Tests/RegexTests/MatchTests.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2549,4 +2549,8 @@ extension RegexTests {
expectProgram(for: "a{\(maxStorable-1),\(maxStorable*2)}", doesNotContain: [.quantify])
expectProgram(for: "a{\(maxStorable),\(maxStorable*2+1)}", doesNotContain: [.quantify])
}

func testFuzzerArtifacts() throws {
expectCompletion(regex: #"(b?)\1*"#, in: "a")
}
}