Place cursor at the end when correcting a message

src/converse-chatview.js

@@ -1012,21 +1012,23 @@
 
                 insertIntoTextArea (value, replace=false, correcting=false) {
                     const textarea = this.el.querySelector('.chat-textarea');
+                    if (correcting) {
+                        u.addClass('correcting', textarea);
+                    } else {
+                        u.removeClass('correcting', textarea);
+                    }
                     if (replace) {
+                        textarea.value = '';
                         textarea.value = value;
                     } else {
                         let existing = textarea.value;
                         if (existing && (existing[existing.length-1] !== ' ')) {
                             existing = existing + ' ';
                         }
+                        textarea.value = '';
                         textarea.value = existing+value+' ';
                     }
-                    if (correcting) {
-                        u.addClass('correcting', textarea);
-                    } else {
-                        u.removeClass('correcting', textarea);
-                    }
-                    textarea.focus()
+                    u.putCurserAtEnd(textarea);
                 },
 
                 createEmojiPicker () {

src/utils/core.js

@@ -849,6 +849,19 @@
         return result;
     };
 
+    u.putCurserAtEnd = function (textarea) {
+        if (textarea !== document.activeElement) {
+            textarea.focus();
+        }
+        // Double the length because Opera is inconsistent about whether a carriage return is one character or two.
+        const len = textarea.value.length * 2;
+        // Timeout seems to be required for Blink
+        setTimeout(() => textarea.setSelectionRange(len, len), 1);
+        // Scroll to the bottom, in case we're in a tall textarea
+        // (Necessary for Firefox and Chrome)
+        this.scrollTop = 999999;
+    };
+
     u.getUniqueId = function () {
         return 'xxxxxxxx-xxxx'.replace(/[x]/g, function(c) {
             var r = Math.random() * 16 | 0,