fix: Fixed handling surrogate characters in insert-after mode in Vim

Author: andrewnester

src/keyboard/vim.js

@@ -3390,9 +3390,11 @@ domLib.importCssString(`.normal-mode .ace_cursor{
         } else if (insertAt == 'bol') {
           head = new Pos(head.line, 0);
         } else if (insertAt == 'charAfter') {
-          head = offsetCursor(head, 0, 1);
+          var newPosition = updateSelectionForSurrogateCharacters(cm, head, offsetCursor(head, 0, 1));
+          head = newPosition.end;
         } else if (insertAt == 'firstNonBlank') {
-          head = motions.moveToFirstNonWhiteSpaceCharacter(cm, head);
+          var newPosition = updateSelectionForSurrogateCharacters(cm, head, motions.moveToFirstNonWhiteSpaceCharacter(cm, head));
+          head = newPosition.end;
         } else if (insertAt == 'startOfSelectedArea') {
           if (!vim.visualMode)
               return;

src/keyboard/vim_test.js

@@ -1850,6 +1850,13 @@ testVim('a_eol', function(cm, vim, helpers) {
   helpers.assertCursorAt(0, lines[0].length);
   eq('vim-insert', cm.getOption('keyMap'));
 });
+testVim('a with surrogate characters', function(cm, vim, helpers) {
+  cm.setCursor(0, 0);
+  helpers.doKeys('a');
+  helpers.doKeys('test');
+  helpers.doKeys('<Esc>');
+  eq('😀test', cm.getValue());
+}, {value: '😀'});
 testVim('A_endOfSelectedArea', function(cm, vim, helpers) {
   cm.setCursor(0, 0);
   helpers.doKeys('v', 'j', 'l');