Backfill empty third-party fields on name dedupe

The tracker policy document deduped third parties by name and kept the
first-seen row wholesale. Org third parties are appended before catalog
common vendors so user-editable data wins, but an org row may leave the
description or privacy policy URL empty. In that case the early return
discarded the later common-vendor row entirely, dropping metadata that
would have completed the document.

Track the kept row by name and backfill only its empty fields from later
duplicates, so org data still wins while common-vendor metadata is no
longer lost.

Signed-off-by: Émile Ré <emile@probo.com>

pkg/probo/tracker_policy_document.go

@@ -325,23 +325,36 @@ func (s *GeneratedDocumentService) buildTrackerPolicyThirdParties(
 	// Dedupe by name so a vendor present both as an org third party (one
 	// pattern) and as a catalog entry (an unlinked pattern) is listed
 	// once. Org third parties are appended first, so their richer
-	// (user-editable) data wins for a shared name.
-	seenName := make(map[string]struct{}, len(thirdParties)+len(commonParties))
+	// (user-editable) data wins for a shared name. When the kept row left a
+	// field empty (e.g. an org third party with no privacy policy URL), a
+	// later duplicate backfills it from the catalog so common-vendor
+	// metadata is not dropped.
+	rowIndexByName := make(map[string]int, len(thirdParties)+len(commonParties))
 
 	addRow := func(name, description, privacyPolicyURL string) {
 		name = strings.TrimSpace(name)
+		description = collapseWhitespace(description)
+		privacyPolicyURL = strings.TrimSpace(privacyPolicyURL)
 
 		key := strings.ToLower(name)
-		if _, ok := seenName[key]; ok {
+		if idx, ok := rowIndexByName[key]; ok {
+			if rows[idx].Description == "" {
+				rows[idx].Description = description
+			}
+
+			if rows[idx].PrivacyPolicyURL == "" {
+				rows[idx].PrivacyPolicyURL = privacyPolicyURL
+			}
+
 			return
 		}
 
-		seenName[key] = struct{}{}
+		rowIndexByName[key] = len(rows)
 
 		rows = append(rows, docgen.TrackerPolicyThirdParty{
 			Name:             name,
-			Description:      collapseWhitespace(description),
-			PrivacyPolicyURL: strings.TrimSpace(privacyPolicyURL),
+			Description:      description,
+			PrivacyPolicyURL: privacyPolicyURL,
 		})
 	}