From 6a8c81205a724f9ca5d181f1891216a943418335 Mon Sep 17 00:00:00 2001
From: Robert Nystrom <rnystrom@google.com>
Date: Tue, 2 Aug 2022 01:43:14 +0000
Subject: [PATCH] Fix a null safety migration bug in update_errors.dart.

It was assigning a List<String> to List<String?> which is allowed due
to (unsound) covariance but would then fail at runtime when null was
assigned to a list element.

Change-Id: Ia893998e8866067b54cfa354b9c4e13d76b6d9ea
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/253303
Auto-Submit: Bob Nystrom <rnystrom@google.com>
Commit-Queue: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Srujan Gaddam <srujzs@google.com>
Commit-Queue: Srujan Gaddam <srujzs@google.com>
---
 pkg/test_runner/lib/src/update_errors.dart   | 4 ++--
 pkg/test_runner/test/update_errors_test.dart | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/pkg/test_runner/lib/src/update_errors.dart b/pkg/test_runner/lib/src/update_errors.dart
index d0640dfa0a3..cb30f048ced 100644
--- a/pkg/test_runner/lib/src/update_errors.dart
+++ b/pkg/test_runner/lib/src/update_errors.dart
@@ -29,7 +29,7 @@ String updateErrorExpectations(String source, List<StaticError> errors,
     }
   }
 
-  List<String?> lines = source.split("\n");
+  var lines = List<String?>.of(source.split("\n"));
 
   // Keep track of the indentation on any existing expectation markers. If
   // found, it will try to preserve that indentation.
@@ -116,7 +116,7 @@ String updateErrorExpectations(String source, List<StaticError> errors,
               error.length != previousLength)) {
         // If the error can't fit in a line comment, or no source location is
         // specified, use an explicit location.
-        if (error.column <= 2 || error.length == 0) {
+        if (error.column <= 2) {
           if (error.length == 0) {
             result.add("$comment [error column "
                 "${error.column}]");
diff --git a/pkg/test_runner/test/update_errors_test.dart b/pkg/test_runner/test/update_errors_test.dart
index 612e69f053e..cf7cb8b58ad 100644
--- a/pkg/test_runner/test/update_errors_test.dart
+++ b/pkg/test_runner/test/update_errors_test.dart
@@ -400,7 +400,7 @@ x
     makeError(line: 1, column: 1, length: 0, cfeError: "Foo"),
   ], expected: """
 x
-// [error column 1, length 0]
+// [error column 1]
 // [cfe] Foo""");
 
   contextMessages();