Fix cursor position after executing J in visual mode

src/actions/commands/actions.ts

@@ -3160,7 +3160,8 @@ class ActionJoin extends BaseCommand {
           manuallySetCursorPositions: true,
         });
 
-        vimState.cursorStartPosition = vimState.cursorStopPosition = startPosition.withColumn(
+        vimState.cursorStartPosition = vimState.cursorStopPosition = new Position(
+          startPosition.line,
           trimmedLinesContent.length - columnDeltaOffset
         );
         await vimState.setCurrentMode(Mode.Normal);

test/mode/modeVisual.test.ts

@@ -1446,4 +1446,12 @@ suite('Mode Visual', () => {
       endMode: Mode.Normal,
     });
   });
+
+  newTest({
+    title: "Can handle 'J' when the selected area spans multiple lines",
+    start: ['o|ne', 'two', 'three', 'four'],
+    keysPressed: 'vjjJ',
+    end: ['one two| three', 'four'],
+    endMode: Mode.Normal,
+  });
 });

test/mode/modeVisualBlock.test.ts

@@ -201,15 +201,15 @@ suite('Mode Visual Block', () => {
     title: "Can handle 'J' when the visual block spans multiple lines",
     start: ['o|ne', 'two', 'three', 'four'],
     keysPressed: '<C-v>jjlJ',
-    end: ['one| two three', 'four'],
+    end: ['one two| three', 'four'],
     endMode: Mode.Normal,
   });
 
   newTest({
     title: "Can handle 'J' when start position of the visual block is below the stop",
     start: ['one', 'two', 't|hree', 'four'],
     keysPressed: '<C-v>kkJ',
-    end: ['one| two three', 'four'],
+    end: ['one two| three', 'four'],
     endMode: Mode.Normal,
   });
 

test/mode/modeVisualLine.test.ts

@@ -520,4 +520,12 @@ suite('Mode Visual Line', () => {
       endMode: Mode.Normal,
     });
   });
+
+  newTest({
+    title: "Can handle 'J' when the selected area spans multiple lines",
+    start: ['o|ne', 'two', 'three', 'four'],
+    keysPressed: 'VjjJ',
+    end: ['one two| three', 'four'],
+    endMode: Mode.Normal,
+  });
 });