[Bug] Merge-conflict resolution silently blanks unrelated Markdown sections

Google Antigravity
1

Summary

Antigravity 2.3.1 on Windows 11 produced a syntactically valid merge-conflict resolution commit that silently replaced multiple substantive Markdown conflict regions with blank lines. The preceding reviewed commit was correct. No conflict markers or write error remained, so ordinary Markdown and link checks passed and the damaged pull request entered the merge queue.

This looks like either semantic conflict resolution choosing empty replacements or the file-edit tool applying a malformed replacement. The public Git history provides exact before/after evidence.

Public reproduction artifacts

Comparing the good and faulty commits shows approximately 125 meaningful lines removed and replaced by blank lines across several separate regions.

Steps that produced the issue

  1. The agent authored and reviewed the documentation update; commit c699af75... contained the intended content.
  2. The branch then required reconciliation with the current main branch.
  3. Antigravity created merge-resolution commit 401fc732....
  4. That commit blanked selected conflict regions while leaving the file syntactically valid and the repository clean.
  5. The PR was considered mergeable and was queued until an independent review compared the merge commit with its parent and detected the loss.

Missing content included

  • The document status row
  • Most of the routing station-semantics table
  • Evidence-source and correlation-envelope definitions
  • Projection-gap findings
  • Accessibility requirements
  • Architecture review guardrails
  • Standards and UX-fit sections
  • Resolved implementation decisions

Expected behavior

Conflict resolution should preserve the reviewed branch content plus applicable changes from main. If resolution is uncertain, Antigravity should leave an explicit conflict or require review. It should never silently substitute empty content for multiple conflict regions.

Actual behavior

Multiple unrelated semantic sections became blank lines without an error, unresolved conflict, or visibly malformed Markdown. This made the data loss difficult for normal syntax/link checks to detect.

Environment and isolation

  • Antigravity version: 2.3.1
  • OS: Windows 11
  • Git worktree isolation was used
  • The worktree was clean before the resolution
  • No concurrent task was editing this worktree when it was later audited
  • Executing model is not available in the retained Git evidence

Request

Please investigate the merge-conflict resolution and file-edit paths for empty replacement hunks. A useful safeguard would compare a generated resolution against both parents and warn or stop when several populated conflict regions become empty without an explicit deletion request.