diff --git a/src/vs/editor/contrib/linesOperations/linesOperations.ts b/src/vs/editor/contrib/linesOperations/linesOperations.ts
index 6fbd9de47dd541c6d56599ea5d41370d1ffb2deb..0e2e13b66b6e14bff6bb135a1c4253a2be97730b 100644
--- a/src/vs/editor/contrib/linesOperations/linesOperations.ts
+++ b/src/vs/editor/contrib/linesOperations/linesOperations.ts
@@ -595,9 +595,9 @@ export class JoinLinesAction extends EditorAction {
 			let selection = reducedSelections[i];
 			let startLineNumber = selection.startLineNumber;
 			let startColumn = 1;
+			let columnDeltaOffset = 0;
 			let endLineNumber: number,
-				endColumn: number,
-				columnDeltaOffset: number;
+				endColumn: number;
 
 			let selectionEndPositionOffset = model.getLineContent(selection.endLineNumber).length - selection.endColumn;
 
diff --git a/src/vs/editor/contrib/linesOperations/test/linesOperations.test.ts b/src/vs/editor/contrib/linesOperations/test/linesOperations.test.ts
index d7ed7bcbf60d159e229920333c527cad218b6f7e..ae01a2682eb91677fbc3189e5775e43cc223a22d 100644
--- a/src/vs/editor/contrib/linesOperations/test/linesOperations.test.ts
+++ b/src/vs/editor/contrib/linesOperations/test/linesOperations.test.ts
@@ -265,6 +265,23 @@ suite('Editor Contrib - Line Operations', () => {
 				});
 		});
 
+		test('#50471 Join lines at the end of document', function () {
+			withTestCodeEditor(
+				[
+					'hello',
+					'world'
+				], {}, (editor, cursor) => {
+					let model = editor.getModel();
+					let joinLinesAction = new JoinLinesAction();
+
+					editor.setSelection(new Selection(2, 1, 2, 1));
+					joinLinesAction.run(null, editor);
+					assert.equal(model.getLineContent(1), 'hello', '001');
+					assert.equal(model.getLineContent(2), 'world', '002');
+					assert.deepEqual(editor.getSelection().toString(), new Selection(2, 6, 2, 6).toString(), '003');
+				});
+		});
+
 		test('should work in multi cursor mode', function () {
 			withTestCodeEditor(
 				[