Merge pull request #3026 from matrix-org/bwindels/tabcompletionfixup

Fixup for tab completion: take part length into account as well

src/editor/parts.js

@@ -314,7 +314,7 @@ export class PillCandidatePart extends PlainPart {
     }
 
     acceptsInsertion(chr, i) {
-        if (i === 0) {
+        if ((this.text.length + i) === 0) {
             return true;
         } else {
             return super.acceptsInsertion(chr, i);