From 2b3691e7cc1831e5a7cb9c8fc3ccbfee4a6c269d Mon Sep 17 00:00:00 2001
From: Alexander Skvortsov <sasha.skvortsov109@gmail.com>
Date: Tue, 18 May 2021 01:37:19 -0400
Subject: [PATCH] Fix insertText

In 60dea59815e10d453421117fa681a6474eb29ec8, insertText was modified from the original to work with reply mentioning. This was done due to a misunderstanding of the API: the selection range isn't the selection to replace, but rather the final selection state after replacing the *current* selection with the text. This commit restores the original, correct implementation of insertText and instead adjusts the `insertBetween`method of BasicEditorDriver to set selection state before executing `insertText`.

Fixes https://github.com/flarum/core/issues/2877
---
 .../js/src/common/utils/BasicEditorDriver.ts  |  6 +++---
 .../core/js/src/common/utils/insertText.ts    | 19 +++++++++++--------
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/framework/core/js/src/common/utils/BasicEditorDriver.ts b/framework/core/js/src/common/utils/BasicEditorDriver.ts
index 077853863..a57bf27c9 100644
--- a/framework/core/js/src/common/utils/BasicEditorDriver.ts
+++ b/framework/core/js/src/common/utils/BasicEditorDriver.ts
@@ -78,10 +78,10 @@ export default class BasicEditorDriver implements EditorDriverInterface {
   }
 
   insertBetween(selectionStart: number, selectionEnd: number, text: string) {
-    insertText(this.el, { text, selectionStart, selectionEnd });
+    this.setSelectionRange(selectionStart, selectionEnd);
 
-    // Move the textarea cursor to the end of the content we just inserted.
-    this.moveCursorTo(selectionStart + text.length);
+    const cursorPos = selectionStart + text.length;
+    insertText(this.el, { text, selectionStart: cursorPos, selectionEnd: cursorPos });
   }
 
   replaceBeforeCursor(start: number, text: string) {
diff --git a/framework/core/js/src/common/utils/insertText.ts b/framework/core/js/src/common/utils/insertText.ts
index 5e44ec637..4f8377c70 100644
--- a/framework/core/js/src/common/utils/insertText.ts
+++ b/framework/core/js/src/common/utils/insertText.ts
@@ -16,16 +16,13 @@ export default function insertText(textarea: HTMLTextAreaElement, { text, select
   const before = textarea.value.slice(0, originalSelectionStart);
   const after = textarea.value.slice(textarea.selectionEnd);
 
-  if (selectionStart != null && selectionEnd != null) {
-    textarea.setSelectionRange(selectionStart, selectionEnd + 1);
-  } else {
-    textarea.setSelectionRange(originalSelectionStart, textarea.selectionEnd);
-  }
-  textarea.focus();
-
   if (canInsertText === null || canInsertText === true) {
     textarea.contentEditable = 'true';
-    canInsertText = document.execCommand('insertText', false, text);
+    try {
+      canInsertText = document.execCommand('insertText', false, text);
+    } catch (error) {
+      canInsertText = false;
+    }
     textarea.contentEditable = 'false';
   }
 
@@ -37,4 +34,10 @@ export default function insertText(textarea: HTMLTextAreaElement, { text, select
     textarea.value = before + text + after;
     textarea.dispatchEvent(new CustomEvent('input', { bubbles: true, cancelable: true }));
   }
+
+  if (selectionStart != null && selectionEnd != null) {
+    textarea.setSelectionRange(selectionStart, selectionEnd);
+  } else {
+    textarea.setSelectionRange(originalSelectionStart, textarea.selectionEnd);
+  }
 }