fix(tui): recover on owned wrap mapping mismatch by fcoury · Pull Request #12 · fcoury/codex

fcoury · 2026-02-23T19:04:22Z

Summary

Replace the panic! in map_owned_wrapped_line_to_range with a recoverable flow that skips synthetic leading characters, logs a warning on mid-line mismatch, and returns the mapped prefix range instead of crashing
Fixes a crash when textwrap produces owned lines with synthetic indent prefixes (e.g. non-space indents via initial_indent/subsequent_indent)

Test plan

Added unit test for direct mismatch recovery (map_owned_wrapped_line_to_range_recovers_on_non_prefix_mismatch)
Added end-to-end wrap_ranges test with non-space indents that forces owned wrapped lines and validates full source reconstruction
Verify no regressions in existing wrapping.rs tests (cargo test -p codex-tui)

Summary by CodeRabbit

Bug Fixes
- Line wrapping is more resilient to indentation-induced mismatches: it recovers partial source mappings instead of failing, logs warnings for partial recoveries, and better preserves formatting across varied indent styles and non-space indents.
Tests
- Added comprehensive tests for wrapping recovery, indentation alignment/divergence, non-prefix edge cases, and end-to-end reconstruction.

Replace the `panic!` path in `tui/src/wrapping.rs` with a recoverable flow. The mapper now skips synthetic leading characters, logs a warning on mid-line mismatch, and returns the mapped prefix range so wrapping continues instead of aborting. Add focused regression coverage for the recovery behavior. Tests now validate direct mismatch recovery and an end-to-end `wrap_ranges` case with non-space indents that forces owned wrapped lines and preserves round-trip source reconstruction.

coderabbitai · 2026-02-23T19:04:49Z

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📥 Commits

Reviewing files that changed from the base of the PR and between c79eefc and f25afcb.

📒 Files selected for processing (1)

codex-rs/tui/src/wrapping.rs

📝 Walkthrough

Walkthrough

Updated wrapping mapping to accept a synthetic prefix, strip it when mapping, and attempt partial recoverable mappings instead of panicking; mapping now tracks whether any source characters were seen and emits a tracing warning on partial recovery. Added tests for indentation and corner cases; function signature changed.

Changes

Cohort / File(s)	Summary
Wrapping logic & tests `codex-rs/tui/src/wrapping.rs`	Added `synthetic_prefix: &str` parameter to `map_owned_wrapped_line_to_range`, updated `wrap_ranges`/`wrap_ranges_trim` to pass synthetic prefixes, changed mapping to strip prefixes, track `saw_source_char`, and return partial ranges with `tracing::warn!` on mismatches instead of panicking. Added extensive tests for partial recovery, indent alignment, non-space indents, overconsumption prevention, and URL-wrap behavior.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

🐰 I nibbled prefixes, peeled them with care,
Matched bits of the source when full matches were rare,
If crumbs stayed behind, I whispered, not cried —
A gentle warn, a recovered stride,
Hopping wrapped lines with joy in the air.

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main change: fixing a panic in wrap mapping by implementing recovery logic for owned wrap mapping mismatches.
Description check	✅ Passed	The description includes a clear summary of changes, specific fixes (replacing panic with recoverable flow), and a comprehensive test plan with implementation status, but lacks a link to an associated bug report or enhancement request as suggested by the template.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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greptile-apps · 2026-02-23T19:06:06Z

Greptile Summary

Replaces a panic-on-mismatch in map_owned_wrapped_line_to_range with a recovery algorithm that tries all possible starting offsets in the wrapped line to find the longest valid source mapping. The fix prevents crashes when textwrap produces owned lines with synthetic indent prefixes (e.g., initial_indent/subsequent_indent options).

Key changes:

Iterates through all character positions in the wrapped line as potential starting points
Tracks the best (longest) mapping found and whether a mismatch occurred after matching source characters
Logs a warning when partial mapping occurs instead of crashing
Adds three new unit tests covering recovery scenarios and indent-prefix edge cases

Confidence Score: 4/5

Safe to merge with minimal risk - replaces crash with graceful recovery
The change is well-tested with three new unit tests covering the edge cases. The recovery algorithm is sound and degrades gracefully by logging warnings instead of panicking. The logic iterates through all possible alignments to find the best match, which is a robust approach for handling synthetic characters from textwrap
No files require special attention

Important Files Changed

Filename	Overview
codex-rs/tui/src/wrapping.rs	Replaces panic with recovery logic for owned wrapped lines; adds comprehensive test coverage including edge cases with synthetic indent prefixes

_{Last reviewed commit: c79eefc}

Copilot

Pull request overview

This PR replaces a panic in map_owned_wrapped_line_to_range with a graceful recovery mechanism that handles textwrap's synthetic indent prefixes. When textwrap produces owned wrapped lines with synthetic characters (e.g., from initial_indent/subsequent_indent options), the function now skips leading synthetic characters and returns partial source ranges with a warning instead of crashing the application.

Changes:

Added saw_source_char flag to track whether any source characters have been matched
Implemented logic to skip synthetic leading characters (e.g., indent prefixes) before matching source content
Replaced panic with warning log and partial range return on mid-line mismatches
Added two comprehensive tests: unit test for direct mismatch recovery and end-to-end test with non-space indents

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Copilot · 2026-02-23T19:08:54Z

codex-rs/tui/src/wrapping.rs

+            continue;
+        }
+
+        tracing::warn!(


The tracing module is used but not imported. Add use tracing; or call the macro with the fully qualified path. Looking at the imports at the top of the file, there is no tracing import, which will cause a compilation error.

Update `map_owned_wrapped_line_to_range` to evaluate candidate starts in owned wrapped output and keep the longest source mapping. This avoids truncating ranges when synthetic indent prefixes share leading characters with source text. Add regression tests for the ambiguous prefix case and an end-to-end `wrap_ranges` reconstruction scenario so this edge case stays covered.

fcoury · 2026-02-23T19:32:58Z

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coderabbitai · 2026-02-23T19:33:04Z

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Pass the expected `initial_indent` or `subsequent_indent` into `map_owned_wrapped_line_to_range` and strip only that validated leading prefix before matching against source bytes. This avoids over-consuming source text when repeated prefix patterns appear in both indent and content. Add a focused regression test that reproduces the repeated `- ` pattern case on narrow widths and asserts the mapper does not over-advance.

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fix(tui): recover on owned wrap mapping mismatch#12

fix(tui): recover on owned wrap mapping mismatch#12
fcoury wants to merge 3 commits intomainfrom
fix-wrapping-panic

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Confidence Score: 4/5

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