Fixes #113318: Show having no change when diffing two empty files

src/vs/editor/common/diff/diffComputer.ts

@@ -313,6 +313,13 @@ export class DiffComputer {
 
 		if (this.original.lines.length === 1 && this.original.lines[0].length === 0) {
 			// empty original => fast path
+			if (this.modified.lines.length === 1 && this.modified.lines[0].length === 0) {
+				return {
+					quitEarly: false,
+					changes: []
+				};
+			}
+
 			return {
 				quitEarly: false,
 				changes: [{

src/vs/editor/test/common/diff/diffComputer.test.ts

@@ -462,6 +462,13 @@ suite('Editor Diff - DiffComputer', () => {
 		assertDiff(original, modified, expected, true, false, true);
 	});
 
+	test('empty diff 5', () => {
+		let original = [''];
+		let modified = [''];
+		let expected: ILineChange[] = [];
+		assertDiff(original, modified, expected, true, false, true);
+	});
+
 	test('pretty diff 1', () => {
 		let original = [
 			'suite(function () {',