FetchURL duplicates GitHub issue body when comments extraction misfires

What version of Kimi Code CLI is running?

Current main checkout (reproduced locally on 2026-04-14).

Which open platform/subscription were you using?

N/A

Which model were you using?

N/A

What platform is your computer?

macOS

What issue are you seeing?

FetchURL can return duplicated text for GitHub issue pages.

For example, fetching https://github.com/MoonshotAI/Moonlight/issues/4 returns:

• the expected issue body once
• then a second malformed copy of the same content, with spacing around inline code removed

The duplicated trailing block looks like this:

The default parameter value for
optimizer
should probably beadamw
instead ofadamW
according to howget_optimizer
is written.

What steps can reproduce the bug?

1. Run the FetchURL tool against https://github.com/MoonshotAI/Moonlight/issues/4
2. Compare the returned text with the expected issue body
3. Observe that the issue body is appended a second time in malformed form

This is also reproducible with:

uv run pytest tests/tools/test_fetch_url.py -k basic_functionality -vv

What is the expected behavior?

FetchURL should return the extracted main content once, without appending a duplicated malformed copy from comment extraction.

Additional information

I traced this to the trafilatura extraction path with include_comments=True.

For this GitHub issue page:

• the main extracted text is correct
• the comments extraction path appears to misclassify the issue body as comment content
• the final output therefore includes both the normal main text and a malformed duplicate "comment" block

I already have a local fix that suppresses extracted comments when they normalize to the same content as the main body, plus a regression test for this case.

Run tests/tools/test_fetch_url.py with the basic_functionality filter and reproduce the GitHub issue URL case. Inspect the FetchURL trafilatura extraction path with include_comments=True, then verify that the main content is returned once and the regression test passes without the duplicated malformed block.