Codex App file viewer leaves initial source lines blank while preserving layout

Codex App version

26.908.40834

Bundled Codex CLI: 0.154.0-alpha.6.2

Subscription

Not provided.

Platform

Darwin 24.6.0 arm64 arm

What issue are you seeing?

The Codex App file viewer intermittently fails to paint the first lines of an ordinary source file. The missing lines still occupy their expected vertical layout space, but the area is blank. Rendering resumes at a later line; in the observed case, line 14 and everything below it were visible while lines 1 through 13 were absent.

The source file itself is intact. Reading it in the terminal shows every line, file reports ordinary ASCII text, and a byte dump shows normal LF line endings with no BOM or control bytes. This is therefore a viewer paint/rendering defect rather than missing or malformed source content.

The problem was also preceded by a file opening as an entirely blank surface when switching out of the review view. Reopening the file explicitly at line 1 did not repaint it; the app queued the open request instead.

Steps to reproduce

1. Open a Git repository in Codex App.
2. Enter the review/file browsing surface.
3. Select a Go source file in the file tree.
4. Switch from the review surface to the regular file viewer, or move between newly created files and existing source files.
5. Observe that an initial contiguous range of source lines may be blank even though later line numbers and code render normally.
6. Verify the same file in a terminal with nl, sed, file, or od; the hidden lines are present and contain normal text.
7. Attempt to reopen the file at line 1. In the observed session this did not repaint the missing lines.

The issue occurred for more than one file-view transition in the same session. No application error was displayed.

Expected behavior

The regular file viewer should render every source line present on disk. Switching between review and file views, including files newly created in the working tree, should not leave blank unpainted ranges or queue a file-open request indefinitely.

Additional information

The blank region retained the exact vertical space of the omitted lines, suggesting that layout or virtualization completed while syntax-highlighted text painting did not. Closing/reopening the view was the only apparent workaround. No source modification is necessary to reproduce or recover the hidden content in another viewer.

Start by reproducing the transition from the review/file browsing surface to the regular file viewer with a Go source file, including newly created files. Inspect the viewer's rendering and queued open-at-line-1 behavior; done means every source line paints after switching views and reopening the file repaints the blank range.