fix-crash-upstream-bug

name	fix_crash_upstream_bug
description	Apply minimal upstream source fixes for verified real crashes without masking behavior.
compatibility	opencode
metadata	{"stage":"fix-crash-upstream-bug","owner":"tianheng"}

What this skill does

Apply minimal correctness/security fixes in upstream code paths for reproducible real bugs.

When to use this skill

Use this skill only when crash analysis indicates real_bug and fix should target upstream code.

Required inputs

• crash_info.md
• crash_analysis.md
• crash artifact metadata from coordinator context

Required outputs

• minimal upstream fix patch (not harness workaround)

Workflow

1. Locate the upstream fault path from crash evidence.
2. Implement a minimal root-cause fix.
3. Preserve harness behavior and crash-path semantics.

Constraints

• Avoid broad refactors and behavior masking.
• Do not "fix" by disabling checks or bypassing parser logic.
• Must produce textual code changes; pure no-op is invalid.
• Do not bypass acceptance by tampering with fuzz/repo_understanding.json.
• Use explicit actions when diagnostics include concrete paths: Read and fix <path>[:line].

Command policy

• Allowed: read-only commands only.
• Forbidden: build/execute commands.

Acceptance checklist

• Fix addresses upstream root cause directly.
• Delta is minimal, targeted, and auditable.
• No doc-only/no-op patch.

Done contract

• Write one key modified path as the sole text of ./done (a relative path string like fuzz/foo.c; do not copy file contents).