From 690ee63bb460273c10b616b10f301fb97bc468ba Mon Sep 17 00:00:00 2001
From: Bruno Windels <brunow@matrix.org>
Date: Thu, 16 May 2019 19:14:24 +0100
Subject: [PATCH] prevent zero-length removals from deleting uneditable parts

This solves an issue where, when backspacing the proceeding character next to a pill,
chrome reports the caret as being in the pill node, not at
the start of the proceeding text node. This would cause the pill
to be removed together with proceeding character.

This is a bug in any case, removing 0 characters
shouldn't remove the part
---
 src/editor/model.js | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/editor/model.js b/src/editor/model.js
index 5a571640c6..13066897b9 100644
--- a/src/editor/model.js
+++ b/src/editor/model.js
@@ -183,21 +183,26 @@ export default class EditorModel {
             // part might be undefined here
             let part = this._parts[index];
             const amount = Math.min(len, part.text.length - offset);
-            if (part.canEdit) {
-                const replaceWith = part.remove(offset, amount);
-                if (typeof replaceWith === "string") {
-                    this._replacePart(index, this._partCreator.createDefaultPart(replaceWith));
-                }
-                part = this._parts[index];
-                // remove empty part
-                if (!part.text.length) {
-                    this._removePart(index);
+            // don't allow 0 amount deletions
+            if (amount) {
+                if (part.canEdit) {
+                    const replaceWith = part.remove(offset, amount);
+                    if (typeof replaceWith === "string") {
+                        this._replacePart(index, this._partCreator.createDefaultPart(replaceWith));
+                    }
+                    part = this._parts[index];
+                    // remove empty part
+                    if (!part.text.length) {
+                        this._removePart(index);
+                    } else {
+                        index += 1;
+                    }
                 } else {
-                    index += 1;
+                    removedOffsetDecrease += offset;
+                    this._removePart(index);
                 }
             } else {
-                removedOffsetDecrease += offset;
-                this._removePart(index);
+                index += 1;
             }
             len -= amount;
             offset = 0;