Add type checks to directory listing.

runtime/bin/directory.cc

Index: runtime/bin/directory.cc
diff --git a/runtime/bin/directory.cc b/runtime/bin/directory.cc
index 5cb4296a395e510bd1da6038dbbd8466dcf23b74..24e1326cbc8f847323686302274d89dec8b4989a 100644
--- a/runtime/bin/directory.cc
+++ b/runtime/bin/directory.cc
@@ -18,37 +18,47 @@ static intptr_t GetHandlerPort(Dart_Handle handle) {
 void FUNCTION_NAME(Directory_List)(Dart_NativeArguments args) {
   Dart_EnterScope();
   Dart_Handle path = Dart_GetNativeArgument(args, 1);
-  bool recursive = DartUtils::GetBooleanValue(Dart_GetNativeArgument(args, 2));
+  Dart_Handle recursive = Dart_GetNativeArgument(args, 2);
   Dart_Port dir_port = GetHandlerPort(Dart_GetNativeArgument(args, 3));
   Dart_Port file_port = GetHandlerPort(Dart_GetNativeArgument(args, 4));
   Dart_Port done_port = GetHandlerPort(Dart_GetNativeArgument(args, 5));
   Dart_Port error_port =
       GetHandlerPort(Dart_GetNativeArgument(args, 6));
-  ASSERT(Dart_IsString(path));
-  Directory::List(DartUtils::GetStringValue(path),
-                  recursive,
-                  dir_port,
-                  file_port,
-                  done_port,
-                  error_port);
+  if (!Dart_IsString(path) || !Dart_IsBoolean(recursive)) {
+    Dart_SetReturnValue(args, Dart_NewBoolean(false));
+  } else {
+    Directory::List(DartUtils::GetStringValue(path),
+                    DartUtils::GetBooleanValue(recursive),
+                    dir_port,
+                    file_port,
+                    done_port,
+                    error_port);
+    Dart_SetReturnValue(args, Dart_NewBoolean(true));
+  }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(Directory_Exists)(Dart_NativeArguments args) {
+  static const int kError = -1;
+  static const int kExists = 1;
+  static const int kDoesNotExist = 0;
   Dart_EnterScope();
   Dart_Handle path = Dart_GetNativeArgument(args, 1);
-  ASSERT(Dart_IsString(path));
-  Directory::ExistsResult result =
-      Directory::Exists(DartUtils::GetStringValue(path));
-  int return_value = -1;
-  if (result == Directory::EXISTS) {
-    return_value = 1;
-  }
-  if (result == Directory::DOES_NOT_EXIST) {
-    return_value = 0;
+  if (Dart_IsString(path)) {
+    Directory::ExistsResult result =
+        Directory::Exists(DartUtils::GetStringValue(path));
+    int return_value = kError;
+    if (result == Directory::EXISTS) {
+      return_value = kExists;
+    }
+    if (result == Directory::DOES_NOT_EXIST) {
+      return_value = kDoesNotExist;
+    }
+    Dart_SetReturnValue(args, Dart_NewInteger(return_value));
+  } else {
+    Dart_SetReturnValue(args, Dart_NewInteger(kDoesNotExist));
   }
-  Dart_SetReturnValue(args, Dart_NewInteger(return_value));
   Dart_ExitScope();
 }
 
@@ -56,9 +66,12 @@ void FUNCTION_NAME(Directory_Exists)(Dart_NativeArguments args) {
 void FUNCTION_NAME(Directory_Create)(Dart_NativeArguments args) {
   Dart_EnterScope();
   Dart_Handle path = Dart_GetNativeArgument(args, 1);
-  ASSERT(Dart_IsString(path));
-  bool created = Directory::Create(DartUtils::GetStringValue(path));
-  Dart_SetReturnValue(args, Dart_NewBoolean(created));
+  if (Dart_IsString(path)) {
+    bool created = Directory::Create(DartUtils::GetStringValue(path));
+    Dart_SetReturnValue(args, Dart_NewBoolean(created));
+  } else {
+    Dart_SetReturnValue(args, Dart_NewBoolean(false));
+  }
   Dart_ExitScope();
 }
 
@@ -66,8 +79,11 @@ void FUNCTION_NAME(Directory_Create)(Dart_NativeArguments args) {
 void FUNCTION_NAME(Directory_Delete)(Dart_NativeArguments args) {
   Dart_EnterScope();
   Dart_Handle path = Dart_GetNativeArgument(args, 1);
-  ASSERT(Dart_IsString(path));
-  bool deleted = Directory::Delete(DartUtils::GetStringValue(path));
-  Dart_SetReturnValue(args, Dart_NewBoolean(deleted));
+  if (Dart_IsString(path)) {
+    bool deleted = Directory::Delete(DartUtils::GetStringValue(path));
+    Dart_SetReturnValue(args, Dart_NewBoolean(deleted));
+  } else {
+    Dart_SetReturnValue(args, Dart_NewBoolean(false));
+  }
   Dart_ExitScope();
 }