openalex._map_paper set Paper.id from the raw `doi` field, which OpenAlex
returns as a full URL (https://doi.org/10.x). The canonical papers.id (M-1
migration) is the bare, lower-cased DOI, so re-ingesting a DOI paper missed
ON CONFLICT (id) and tripped the separate papers_openalex_id_key constraint
(UniqueViolation).
Fix: _normalize_doi() strips https://doi.org//http://doi.org//doi: and
lower-cases; applied in the DOI branch of _map_paper only (W-id fallback
untouched). Also un-breaks _s2_id_for/Crossref recovery, which the URL form
silently defeated. Corrected the _SAMPLE_WORK fixture to the URL form (the bare
fixture hid the bug) + added _normalize_doi and re-ingest idempotency regression
tests.
Live verification: re-ingest of 10.1007/s00454-019-00132-8 (previously crashed)
now UPDATEs in place — single row, added_at unchanged, no stray row, citations
45->45. Unblocks roadmap R-A/R-C. Full suite 348 green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Three papers lacked abstracts and 1911.00966 was fully degraded (OpenAlex 404
-> empty `Paper(id, title="")` stub). Recovery sources verified, then wired in:
- arxiv.fetch_metadata: resolve an arXiv id to a Paper via the Atom export API
(authoritative for preprints). Used as an ingest fallback on OpenAlex 404,
replacing the empty stub.
- crossref.py (new): fetch_abstract(doi), JATS-stripped, Crossref Polite Pool.
- semanticscholar.fetch_abstract: fetch just the abstract field.
- ingest.py: _recover_abstract() supplements an empty abstract from S2 then
Crossref *before* embedding, so the paper gets a real (non-zero) vector.
Live DB backfill: 1911.00966 fully recovered from arXiv (bibkey
PinkallSpringborn2019, 384-char abstract, its 10 chunks now visible to chunk
search); 10.1007/s00454-019-00132-8 abstract from S2 (1186 chars). Book chapter
10.1007/978-3-642-17413-1_7 has no abstract in OpenAlex/S2/Crossref -> documented
limit. Corpus now has 1 paper without an abstract.
Also documented DQ-5 (not fixed): ingest_paper is not idempotent for DOI papers
(openalex returns full-URL id vs the bare canonical id) -> re-ingest trips
papers_openalex_id_key. Blocks roadmap R-A/R-C; needs a careful _map_paper fix.
Tests: arxiv/crossref/s2 fetchers + ingest recovery paths (342 passing).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
12/29 papers had zero citations: OpenAlex indexes arXiv preprints and theses
without a parsed reference list (verified referenced_works_count=0 server-side
for all 11 with an openalex_id). Not an ingest bug — a source-coverage limit.
- ingest.py: when OpenAlex returns no references, fall back to a Semantic
Scholar reference supplement (_s2_reference_supplement); citing_id rewritten
to canonical papers.id, DOI cited-ids lowercased. Removed a now-redundant
discarded S2 probe in the OpenAlex-404 arXiv branch.
- semanticscholar.py: fix TypeError on S2's HTTP-200 {"data": null} no-refs
responses (.get("data", []) returns None when the key is present-but-null).
- tests: regression test for the OpenAlex-empty -> S2 path.
- Live DB backfilled idempotently: +330 citations (590->920), zero-out-edge
papers 12->2, citing coverage 17->27/29. Only the 2 TU-Berlin depositonce
theses remain (no references in any source).
- docs: DATA-QUALITY-2026-06-15.md — DQ-1 resolution, DQ-4 result, and a
free-source acquisition roadmap (R-A..R-E).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Committed code predated the line-length=100 ruff config; this brings the
five drifted files into compliance. No logic change.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
