[debugger] fix debug-evaluate wrt shadowed context var.

src/ast/scopes.cc

Index: src/ast/scopes.cc
diff --git a/src/ast/scopes.cc b/src/ast/scopes.cc
index 1eda493d6e5d7880e709824e659c4958319a2cca..946f304b940ee831d3ba8950ebf0467a7c6d7266 100644
--- a/src/ast/scopes.cc
+++ b/src/ast/scopes.cc
@@ -842,6 +842,22 @@ void Scope::GetNestedScopeChain(Isolate* isolate,
 }
 
 
+void Scope::CollectNonLocals(HashMap* non_locals) {
+  // Collect non-local variables referenced in the scope.
+  for (int i = 0; i < unresolved_.length(); i++) {

[rossberg, 2015/12/09 14:53:46]

This scares me! It assumes that all non-locals are still unresolved, which is
very (too) brittle. It may not even be the case for all variables (we may
resolve some more eagerly, I'm not sure, or may want to do so in the future).

+    VariableProxy* proxy = unresolved_[i];
+    if (proxy->is_resolved() && proxy->var()->IsStackAllocated()) continue;
+    Handle<String> name = proxy->name();
+    void* key = reinterpret_cast<void*>(name.location());
+    HashMap::Entry* entry = non_locals->LookupOrInsert(key, name->Hash());
+    entry->value = key;
+  }
+  for (int i = 0; i < inner_scopes_.length(); i++) {
+    inner_scopes_[i]->CollectNonLocals(non_locals);
+  }
+}
+
+
 void Scope::ReportMessage(int start_position, int end_position,
                           MessageTemplate::Template message,
                           const AstRawString* arg) {