Triage Expect.

dart/frog/leg/ssa/codegen.dart

Index: dart/frog/leg/ssa/codegen.dart
diff --git a/dart/frog/leg/ssa/codegen.dart b/dart/frog/leg/ssa/codegen.dart
index 9898eedbea91b91dc9da966a5020f7f769987656..76e76b2f465a7aedf8c757509c196814c15413e3 100644
--- a/dart/frog/leg/ssa/codegen.dart
+++ b/dart/frog/leg/ssa/codegen.dart
@@ -805,8 +805,11 @@ class SsaCodeGenerator implements HVisitor {
       checkObject(input, '===');
       buffer.add(' && (');
       if (element == coreLibrary.find(const SourceString('List'))) {
+        buffer.add('(');
+        checkObject(input, '===');

[ngeoffray, 2012/02/21 12:23:51]

checkObject is already done line 805.

+        buffer.add(' && ');
         checkArray(input, '===');
-        buffer.add(' || ');
+        buffer.add(') || ');
       }
       buffer.add('!!(');
       use(input);
@@ -890,15 +893,19 @@ class SsaOptimizedCodeGenerator extends SsaCodeGenerator {
       bailout(node, 'Not a string');
     } else if (node.isArray()) {
       buffer.add('if (');
+      checkObject(input, '!==');

[ngeoffray, 2012/02/21 12:23:51]

Please add a comment that this is actually a null check.

+      buffer.add('||');
       checkArray(input, '!==');
       buffer.add(') ');
       bailout(node, 'Not an array');
     } else if (node.isStringOrArray()) {
       buffer.add('if (');
       checkString(input, '!==');
-      buffer.add(' && ');
+      buffer.add(' && (');
+      checkObject(input, '!==');
+      buffer.add('||');
       checkArray(input, '!==');
-      buffer.add(') ');
+      buffer.add(')) ');
       bailout(node, 'Not a string or array');
     } else {
       unreachable();