fix bug when saving non-text notes

src/services/consistency_checks.js

@@ -209,6 +209,16 @@ async function runAllChecks() {
             AND type != 'relation-map'`,
         "Note has invalid type", errorList);
 
+    await runCheck(`
+          SELECT
+            noteId
+          FROM
+            notes
+          WHERE
+            isDeleted = 0
+            AND content IS NULL`,
+        "Note content is null even though it is not deleted", errorList);
+
     await runCheck(`
           SELECT 
             parentNoteId

src/services/notes.js

@@ -219,7 +219,7 @@ function findRelationMapLinks(content, foundLinks) {
 
 async function saveLinks(note, content) {
     if (note.type !== 'text' && note.type !== 'relation-map') {
-        return;
+        return content;
     }
 
     const foundLinks = [];