From cfbb3d3d4717347e407fca0f7547ce99317f8842 Mon Sep 17 00:00:00 2001
From: Dan Stillman <dstillman@zotero.org>
Date: Mon, 11 Jun 2018 12:16:09 -0400
Subject: [PATCH] Mendeley import: Fix "Collection undefined not found" error

If a folder appeared in the DocumentFolders table but not in
Folders/RemoteFolders, it caused an error.
---
 chrome/content/zotero/import/mendeley/mendeleyImport.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/chrome/content/zotero/import/mendeley/mendeleyImport.js b/chrome/content/zotero/import/mendeley/mendeleyImport.js
index 4f739c6a2..c7b56f082 100644
--- a/chrome/content/zotero/import/mendeley/mendeleyImport.js
+++ b/chrome/content/zotero/import/mendeley/mendeleyImport.js
@@ -428,7 +428,12 @@ Zotero_Import_Mendeley.prototype._getDocumentCollections = async function (group
 	for (let row of rows) {
 		let keys = map.get(row.documentId);
 		if (!keys) keys = [];
-		keys.push(folderKeys.get(row.folderId));
+		let key = folderKeys.get(row.folderId);
+		if (!key) {
+			Zotero.debug(`Document folder ${row.folderId} not found -- skipping`, 2);
+			continue;
+		}
+		keys.push(key);
 		map.set(row.documentId, keys);
 	}
 	return map;