fix: collision prevent

internal/topdata/wiki_deploy.go

@@ -760,8 +760,16 @@ func shouldCheckRemoteTopicTitle(previous wikiDeployManifestPage, pageTitle, des
 
 func recoverCreateCollision(plan wikiDeployPlan, manifest wikiDeployManifest, client *nodeBBClient, summary string) (bool, error) {
 	entry, ok, err := findExistingNodeBBPage(plan.Page, plan.Entry.CID, client)
+	if err != nil {
+		return false, err
+	}
+	if !ok {
+		// Search-based lookup failed. NodeBB confirmed the collision, so the page definitely
+		// exists — fall back to listing the category and matching by title.
+		entry, ok, err = findCollisionPageByTitle(plan.Page, plan.Entry.CID, client)
 		if err != nil || !ok {
-		return ok, err
+			return false, err
+		}
 	}
 	remote, err := client.getPost(entry.PID)
 	if err != nil {
@@ -801,6 +809,15 @@ func adoptExistingNodeBBPage(page wikiDeployPage, cid int, remotePagesByCID map[
 		if err := nestedCanonicalAdoptionFallbackError(page, remotePages); err != nil {
 			return wikiDeployManifestPage{}, false, err
 		}
+		// For nested-path pages: nestedCanonicalAdoptionFallbackError only examined pages
+		// without WikiPath/CanonicalPath. Pages that have those fields set but whose stored
+		// path doesn't normalize to match the local PublicPath (e.g. different slug format)
+		// still need to be adopted. Try an unambiguous title match across all remote pages.
+		if isNestedCanonicalWikiPath(page.PublicPath) {
+			if remotePage, ok := matchByTitle(page, remotePages); ok && remotePage.TID != 0 {
+				return fetchNodeBBWikiPageMapping(page, cid, remotePage, client)
+			}
+		}
 		return wikiDeployManifestPage{}, false, nil
 	}
 	return fetchNodeBBWikiPageMapping(page, cid, remotePage, client)
@@ -834,6 +851,42 @@ func findExistingNodeBBPage(page wikiDeployPage, cid int, client *nodeBBClient)
 	return wikiDeployManifestPage{}, false, nil
 }
 
+func findCollisionPageByTitle(page wikiDeployPage, cid int, client *nodeBBClient) (wikiDeployManifestPage, bool, error) {
+	remotePages, err := client.listNamespacePages(cid)
+	if err != nil {
+		return wikiDeployManifestPage{}, false, err
+	}
+	remotePage, ok := matchByTitle(page, remotePages)
+	if !ok || remotePage.TID == 0 {
+		return wikiDeployManifestPage{}, false, nil
+	}
+	return fetchNodeBBWikiPageMapping(page, cid, remotePage, client)
+}
+
+func matchByTitle(page wikiDeployPage, remotePages []nodeBBWikiPage) (nodeBBWikiPage, bool) {
+	desiredTitle := normalizeWikiTitle(page.Title)
+	if desiredTitle == "" {
+		return nodeBBWikiPage{}, false
+	}
+	var match *nodeBBWikiPage
+	for i, candidate := range remotePages {
+		for _, title := range []string{candidate.TitleLeaf, candidate.Title} {
+			if normalizeWikiTitle(title) == desiredTitle {
+				if match != nil {
+					return nodeBBWikiPage{}, false // ambiguous — refuse to guess
+				}
+				cp := remotePages[i]
+				match = &cp
+				break
+			}
+		}
+	}
+	if match == nil {
+		return nodeBBWikiPage{}, false
+	}
+	return *match, true
+}
+
 func uniqueNodeBBPageSearchQueries(values ...string) []string {
 	queries := []string{}
 	seen := map[string]struct{}{}