fix(tui): guard backgroundAt against infinite loop on invalid UTF-8 - #3799
Merged
Conversation
Adds an n == 0 break in the decode loop so malformed input that ansi.DecodeSequence cannot advance past doesn't spin forever. Assisted-By: Claude
gtardif
approved these changes
Jul 23, 2026
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
2 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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
ansi.DecodeSequencecan returnn == 0when it encounters invalid UTF-8, such as an isolated continuation byte. ThebackgroundAtfunction in the copy-feedback component loops over ANSI sequences until it has consumed the full input, but it never checked for this case — meaning a single bad byte would cause the loop to spin forever and freeze the TUI.The fix adds an early
breakwhenn == 0, preventing the infinite loop regardless of what byte sequence is fed in. A regression test case, "invalid utf-8 terminates", is added toTestBackgroundAtto cover this path.This follows up on review feedback from #3797 (#3797 (comment)).