Repository navigation
[3.15] gh-155525: Fix quadratic f-string tokenization (GH-156756) - #157828
Merged
pablogsal merged 3 commits intoSep 19, 2026
Merged
pablogsal merged 3 commits into
pablogsal merged 3 commits into
Conversation
Copy link
Copy Markdown
Contributor
Sorry, something went wrong.
Adapt the original expression-span fix to the release tokenizer and retain interactive buffers while a formatted string is open. Co-authored-by: gwosti <322952417+gwosti@users.noreply.github.com>
…thonGH-156756) * pythongh-155525: Avoid quadratic f-string tokenization * fixup! pythongh-155525: Avoid quadratic f-string tokenization --------- (cherry picked from commit c1df684) Co-authored-by: gwosti <322952417+gwosti@users.noreply.github.com> Co-authored-by: Pablo Galindo Salgado <Pablogsal@gmail.com>
pablogsal
approved these changes
Sep 19, 2026
pablogsal
left a comment
Copy link
Copy Markdown
Member
There was a problem hiding this comment.
The release tokenizer fix and interactive buffer retention are included. The final tree matches the debug build tested locally: 702 tests passed, including the CPU-resource cases and the new interactive regression.
Sorry, something went wrong.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Reviewers
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Backport gh-156756 to Python 3.15. Retain replacement expressions in the tokenizer buffer instead of repeatedly copying the remaining source. Preserve the expression pointers when the buffer grows, and keep the interactive buffer while a formatted string is open.
Main already received the implementation through gh-156484, so the automatic cherry-pick only brought over tests. This backport also adapts the original fix to the release tokenizer and adds coverage for multiline interactive expressions, which otherwise abort in a debug build.
The targeted parser and command-line tests pass in a debug build, including the CPU-resource tests.
(cherry picked from commit c1df684)