patchscan: distinguish E: (verification errors) from W: (missing fixes)

[nirmoy]

Summary

• Bug: E: (upstream commit-message mismatch) and W: (missing Fixes: patch) both set fixes_found=true, so the :warning: Missing Fixes Detected comment appeared even when All fixes: was empty and no patches were actually missing.
• Root cause 1: Two separate if blocks both wrote to GITHUB_OUTPUT for the same variable; the second write (true/false) always overwrote the first (error).
• Root cause 2: The [Uu]pstream commit regex in get_src_commit_strs() matched upstream commit <sha> embedded in prose (e.g. "was removed by upstream commit d18f1b7"), not just as a backport trailer. Jacob's original script uses only from commit, which correctly ignores such prose references.
• Fix 1: Replace two independent if blocks with a single mutually-exclusive if/elif/else chain:
  • W: / Fixes for → fixes_found=true → "Missing Fixes Detected" comment
  • E: / non-zero exit → fixes_found=error → "Upstream Verification Error" comment
  • neither → fixes_found=false → all-clear comment
• Fix 2: Anchor [Uu]pstream commit to line start with re.MULTILINE so it only matches as a standalone trailer, not in prose.

Triggered by PR #342, where commit ad33ca9f (a SAUCE config commit) had upstream commit d18f1b7beadf in its description prose — not a backport marker — causing a spurious failure.

Test plan

• Re-run patchscan against a PR with only E: errors — should post :x: Upstream Verification Error comment and fail the check
• Verify a PR with actual missing Fixes: patches still posts :warning: Missing Fixes Detected
• Verify a clean PR still posts :white_check_mark: No Missing Fixes
• Verify ad33ca9f-style prose reference (upstream commit X not at line start) is no longer matched

Tested on nirmoy/NV-Kernels fork — see comments below for details.

🤖 Generated with Claude Code

[nirmoy]

Tested all three paths against the fork (nirmoy/NV-Kernels) with the fix applied:

Test	PR	Result	Comment posted
E: only — SAUCE commit references upstream SHA with different title	#9	❌ fail	:x: Patchscan: Upstream Verification Error
W: — commit with backported SHA that has a missing Fixes: patch	#8	⚠️ fail	:warning: Patchscan: Missing Fixes Detected
Clean — no upstream references	#6	✅ pass	:white_check_mark: Patchscan: No Missing Fixes

The E: case previously posted a misleading "Missing Fixes Detected" comment with an empty All fixes: section. It now correctly posts "Upstream Verification Error" with an explanation that this is often a false positive from SAUCE commits.

[nvmochs]

I don't have an issue with this change. However, why did the script think the "PCI/AER: Replace PCIEAER_CXL symbol with CXL_RAS" reference was an upstream SHA? Shouldn't it only consider those that have a pick tag?

[nvmochs]

When I run Jacob's patchscan on Jiandi's CXL branch it did not flag anything for that patch:

❯ patchscan HEAD~5..HEAD upstream master 
Fetching upstream upstream/master...
Checking 5 commits...
checking 5c7000239d1f361f5e8048f4e2ce3a7f9f75e619 NVIDIA: VR: SAUCE: [Config] Add PCI_CXL annotation for CXL state save/restore..... no upstream reference
checking 51885043a12289fecc405e84fd7910d2e982fddc NVIDIA: VR: SAUCE: [Config] Enable CXL DAX and KMEM built-in for CXL memory access..... no upstream reference
checking ad33ca9f32214a31e6ee40573d6c844e9557d8ae NVIDIA: VR: SAUCE: [Config] CXL config annotations for Type-2 device and RAS support..... no upstream reference
checking fc562f73981b9e22e810e2f1f50612935cefc627 NVIDIA: VR: SAUCE: Documentation: ABI: Add CXL PCI cxl_reset sysfs attribute..... no upstream reference
checking 43a1ddec5c38b4d1bbf32ceb3f9827c662a25793 NVIDIA: VR: SAUCE: cxl: Add cxl_reset sysfs interface for PCI devices..... no upstream reference
All fixes:

[nirmoy]

The fight #356 beweeen claude abd copilot must have forced claude to modify the Jacob's script. Checking..

[nirmoy]

Shouldn't it only consider those that have a pick tag?

You're correct — the original script does exactly that. The [Uu]pstream commit pattern was added to .github/scripts/patchscan during the PR #356 review process to support an additional trailer format (Upstream commit <sha> as a standalone line). Without anchoring it to the start of a line, it also matched upstream commit appearing in prose, which is what ad33ca9f contains:

...was removed from Kconfig by upstream commit d18f1b7beadf
(PCI/AER: Replace PCIEAER_CXL symbol with CXL_RAS) which is included
in this port.

The fix applied in this PR adds re.MULTILINE and a ^ anchor so it only matches as a line-start trailer:

re.finditer(r"(?:from commit|^[Uu]pstream commit) ([a-fA-F0-9]+)", msg, re.MULTILINE)

With this fix ad33ca9f correctly returns "no upstream reference", matching Jacob's original script behaviour.

— Claude

[nirmoy]

Superseded by a new PR that also adds 26.04_linux-nvidia support.