diff --git a/pkg/front_end/test/spell_checking_list_common.txt b/pkg/front_end/test/spell_checking_list_common.txt
index 86ae2aa3378..b8a5ce2b833 100644
--- a/pkg/front_end/test/spell_checking_list_common.txt
+++ b/pkg/front_end/test/spell_checking_list_common.txt
@@ -251,6 +251,7 @@ best
 bets
 better
 between
+beyond
 big
 bigint
 binaries
diff --git a/pkg/front_end/testcases/general/error_locations/error_location_05.dart b/pkg/front_end/testcases/general/error_locations/error_location_05.dart
new file mode 100644
index 00000000000..98a013da369
--- /dev/null
+++ b/pkg/front_end/testcases/general/error_locations/error_location_05.dart
@@ -0,0 +1,7 @@
+// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library error_location_05;
+
+part 'error_location_05_lib1.dart';
diff --git a/pkg/front_end/testcases/general/error_locations/error_location_05.dart.outline.expect b/pkg/front_end/testcases/general/error_locations/error_location_05.dart.outline.expect
new file mode 100644
index 00000000000..ee7a72e6c08
--- /dev/null
+++ b/pkg/front_end/testcases/general/error_locations/error_location_05.dart.outline.expect
@@ -0,0 +1,18 @@
+library error_location_05;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart:7:8: Error: Duplicated parameter name 'z'.
+// x1(z, {z}) {}
+//        ^
+// pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart:7:4: Context: Other parameter named 'z'.
+// x1(z, {z}) {}
+//    ^
+//
+import self as self;
+
+part error_location_05_lib1.dart;
+static method /* from org-dartlang-testcase:///error_location_05_lib1.dart */ x1(dynamic z, {dynamic z}) → dynamic
+  ;
+static method /* from org-dartlang-testcase:///error_location_05_lib1.dart */ x2() → dynamic
+  ;
diff --git a/pkg/front_end/testcases/general/error_locations/error_location_05.dart.strong.expect b/pkg/front_end/testcases/general/error_locations/error_location_05.dart.strong.expect
new file mode 100644
index 00000000000..a52047a7ed5
--- /dev/null
+++ b/pkg/front_end/testcases/general/error_locations/error_location_05.dart.strong.expect
@@ -0,0 +1,30 @@
+library error_location_05;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart:7:8: Error: Duplicated parameter name 'z'.
+// x1(z, {z}) {}
+//        ^
+// pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart:7:4: Context: Other parameter named 'z'.
+// x1(z, {z}) {}
+//    ^
+//
+// pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart:10:9: Error: 'z' is already declared in this scope.
+//   y(z, {z}) {}
+//         ^
+// pkg/front_end/testcases/general/error_locations/error_location_05.dart:7:27: Context: Previous declaration of 'z'.
+// part 'error_location_05_lib1.dart';
+//                           ^
+//
+import self as self;
+import "dart:core" as core;
+
+part error_location_05_lib1.dart;
+static method /* from org-dartlang-testcase:///error_location_05_lib1.dart */ x1(dynamic z = #C1, {dynamic z = #C1}) → dynamic {}
+static method /* from org-dartlang-testcase:///error_location_05_lib1.dart */ x2() → dynamic {
+  function y(dynamic z, {dynamic z = #C1}) → core::Null? {}
+}
+
+constants  {
+  #C1 = null
+}
diff --git a/pkg/front_end/testcases/general/error_locations/error_location_05.dart.strong.transformed.expect b/pkg/front_end/testcases/general/error_locations/error_location_05.dart.strong.transformed.expect
new file mode 100644
index 00000000000..a52047a7ed5
--- /dev/null
+++ b/pkg/front_end/testcases/general/error_locations/error_location_05.dart.strong.transformed.expect
@@ -0,0 +1,30 @@
+library error_location_05;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart:7:8: Error: Duplicated parameter name 'z'.
+// x1(z, {z}) {}
+//        ^
+// pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart:7:4: Context: Other parameter named 'z'.
+// x1(z, {z}) {}
+//    ^
+//
+// pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart:10:9: Error: 'z' is already declared in this scope.
+//   y(z, {z}) {}
+//         ^
+// pkg/front_end/testcases/general/error_locations/error_location_05.dart:7:27: Context: Previous declaration of 'z'.
+// part 'error_location_05_lib1.dart';
+//                           ^
+//
+import self as self;
+import "dart:core" as core;
+
+part error_location_05_lib1.dart;
+static method /* from org-dartlang-testcase:///error_location_05_lib1.dart */ x1(dynamic z = #C1, {dynamic z = #C1}) → dynamic {}
+static method /* from org-dartlang-testcase:///error_location_05_lib1.dart */ x2() → dynamic {
+  function y(dynamic z, {dynamic z = #C1}) → core::Null? {}
+}
+
+constants  {
+  #C1 = null
+}
diff --git a/pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart b/pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart
new file mode 100644
index 00000000000..f896142d63e
--- /dev/null
+++ b/pkg/front_end/testcases/general/error_locations/error_location_05_lib1.dart
@@ -0,0 +1,11 @@
+// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+part of error_location_05;
+
+x1(z, {z}) {}
+
+x2() {
+  y(z, {z}) {}
+}
diff --git a/pkg/front_end/testcases/general/error_locations/error_location_06.dart b/pkg/front_end/testcases/general/error_locations/error_location_06.dart
new file mode 100644
index 00000000000..b97ac236c37
--- /dev/null
+++ b/pkg/front_end/testcases/general/error_locations/error_location_06.dart
@@ -0,0 +1,7 @@
+// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library error_location_06;
+
+part 'error_location_06_lib1.dart';
diff --git a/pkg/front_end/testcases/general/error_locations/error_location_06.dart.outline.expect b/pkg/front_end/testcases/general/error_locations/error_location_06.dart.outline.expect
new file mode 100644
index 00000000000..6f0dc86f762
--- /dev/null
+++ b/pkg/front_end/testcases/general/error_locations/error_location_06.dart.outline.expect
@@ -0,0 +1,18 @@
+library error_location_06;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/error_locations/error_location_06_lib1.dart:12:8: Error: Duplicated parameter name 'z'.
+// x1(z, {z}) {}
+//        ^
+// pkg/front_end/testcases/general/error_locations/error_location_06_lib1.dart:12:4: Context: Other parameter named 'z'.
+// x1(z, {z}) {}
+//    ^
+//
+import self as self;
+
+part error_location_06_lib1.dart;
+static method /* from org-dartlang-testcase:///error_location_06_lib1.dart */ x1(dynamic z, {dynamic z}) → dynamic
+  ;
+static method /* from org-dartlang-testcase:///error_location_06_lib1.dart */ x2() → dynamic
+  ;
diff --git a/pkg/front_end/testcases/general/error_locations/error_location_06_lib1.dart b/pkg/front_end/testcases/general/error_locations/error_location_06_lib1.dart
new file mode 100644
index 00000000000..47a8883fc9b
--- /dev/null
+++ b/pkg/front_end/testcases/general/error_locations/error_location_06_lib1.dart
@@ -0,0 +1,16 @@
+// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Lots of comment lines that pushes the length of this file beyond that of
+// error_location_06. This in turn causes the (first) 'z' in 'x2' to get an
+// offset that is larger than the largest valid offset in error_location_06.
+// This in turn can cause a crash, if the fileUri for that z is the wrong file.
+
+part of error_location_06;
+
+x1(z, {z}) {}
+
+x2() {
+  y(z, {z}) {}
+}
diff --git a/pkg/front_end/testcases/strong.status b/pkg/front_end/testcases/strong.status
index 631d8d53648..e3eb239cdef 100644
--- a/pkg/front_end/testcases/strong.status
+++ b/pkg/front_end/testcases/strong.status
@@ -6,6 +6,9 @@
 # Kernel ASTs directly, that is, code in pkg/fasta/lib/src/kernel/ with
 # strong-mode enabled.
 
+general/error_locations/error_location_05: RuntimeError # Has errors in it.
+general/error_locations/error_location_06: Crash # Has errors in it.
+
 extensions/instance_access_of_static: RuntimeError
 extensions/invalid_explicit_access: RuntimeError
 extensions/static_access_of_instance: RuntimeError
diff --git a/pkg/front_end/testcases/text_serialization.status b/pkg/front_end/testcases/text_serialization.status
index 05fec194ac8..f8bdbecfa1e 100644
--- a/pkg/front_end/testcases/text_serialization.status
+++ b/pkg/front_end/testcases/text_serialization.status
@@ -131,6 +131,8 @@ general/error_locations/error_location_01: TextSerializationFailure
 general/error_locations/error_location_02: TextSerializationFailure
 general/error_locations/error_location_03: TextSerializationFailure
 general/error_locations/error_location_04: TextSerializationFailure
+general/error_locations/error_location_05: TextSerializationFailure
+general/error_locations/error_location_06: Crash
 general/escape: TextSerializationFailure # Was: Pass
 general/export_main: TextSerializationFailure # Was: Pass
 general/export_test: TextSerializationFailure # Was: Pass