Post on the error handler in the Directory API when errors are encountered.

runtime/bin/directory_win.cc

Index: runtime/bin/directory_win.cc
diff --git a/runtime/bin/directory_win.cc b/runtime/bin/directory_win.cc
index d3adfb83e46e3fbc19e026017d6b1a8249f4314c..8fc4cc0aec17daa48abbc7408086891137607de8 100644
--- a/runtime/bin/directory_win.cc
+++ b/runtime/bin/directory_win.cc
@@ -106,6 +106,24 @@ static void ComputeFullSearchPath(const char* dir_name,
   *path_length += written;
 }
 
+static void PostError(Dart_Port error_port,
+                      const char* prefix,
+                      const char* suffix) {
+  if (error_port != 0) {
+    int error_message_size = strlen(prefix) + strlen(suffix);
+    char* buffer = static_cast<char*>(malloc(error_message_size + 1));
+    int written = snprintf(buffer,
+                           error_message_size + 1,
+                           "%s%s",
+                           prefix,
+                           suffix);
+    ASSERT(written == error_message_size);
+    Dart_Post(error_port, Dart_NewString(buffer));
+    free(buffer);
+  }
+}
+
+
 static bool ListRecursively(const char* dir_name,
                             bool recursive,
                             Dart_Port dir_port,
@@ -124,7 +142,7 @@ static bool ListRecursively(const char* dir_name,
   path[path_length] = '\0';
 
   if (find_handle == INVALID_HANDLE_VALUE) {
-    // TODO(ager): Post on error port.
+    PostError(error_port, "Directory listing failed for: ", path);
     free(path);
     return false;
   }
@@ -138,7 +156,7 @@ static bool ListRecursively(const char* dir_name,
                                done_port,
                                error_port);
 
-  while (FindNextFile(find_handle, &find_file_data) != 0) {
+  while ((FindNextFile(find_handle, &find_file_data) != 0) && completed) {
     completed = completed && HandleEntry(&find_file_data,
                                          path,
                                          path_length,
@@ -149,10 +167,18 @@ static bool ListRecursively(const char* dir_name,
                                          error_port);
   }
 
-  completed = completed && (GetLastError() == ERROR_NO_MORE_FILES);
+  if (GetLastError() != ERROR_NO_MORE_FILES) {
+    completed = false;
+    PostError(error_port, "Directory listing failed", "");
+  }
 
-  // TODO(ager): Post on error port if close fails.
-  FindClose(find_handle);
+  if (FindClose(find_handle) != 0) {
+    static const int kBufferSize = 10;
+    char error_str[kBufferSize];
+    int written = snprintf(error_str, kBufferSize, "%d", GetLastError());
+    ASSERT(written < kBufferSize);
+    PostError(error_port, "Failed to close directory. ErrorCode: ", error_str);
+  }
   free(path);
 
   return completed;