Fix Dir#info on Windows

spec/std/dir_spec.cr

@@ -68,15 +68,14 @@ describe "Dir" do
       end
     end
 
-    # TODO: do we even want this?
-    pending_win32 "tests empty? on a directory path to a file" do
+    it "tests empty? on a directory path to a file" do
       expect_raises(File::Error, "Error opening directory: '#{datapath("dir", "f1.txt", "/").inspect_unquoted}'") do
         Dir.empty?(datapath("dir", "f1.txt", "/"))
       end
     end
   end
 
-  pending_win32 "tests info on existing directory" do
+  it "tests info on existing directory" do
     Dir.open(datapath) do |dir|
       info = dir.info
       info.directory?.should be_true

src/crystal/system/win32/dir.cr

@@ -6,10 +6,11 @@ require "c/processenv"
 
 module Crystal::System::Dir
   private class DirHandle
-    property handle : LibC::HANDLE
+    property iter_handle : LibC::HANDLE
+    property file_handle : LibC::HANDLE = LibC::INVALID_HANDLE_VALUE
     getter query : LibC::LPWSTR
 
-    def initialize(@handle, @query)
+    def initialize(@iter_handle, @query)
     end
   end
 
@@ -22,11 +23,11 @@ module Crystal::System::Dir
   end
 
   def self.next_entry(dir : DirHandle, path : String) : Entry?
-    if dir.handle == LibC::INVALID_HANDLE_VALUE
+    if dir.iter_handle == LibC::INVALID_HANDLE_VALUE
       # Directory is at start, use FindFirstFile
       handle = LibC.FindFirstFileW(dir.query, out data)
       if handle != LibC::INVALID_HANDLE_VALUE
-        dir.handle = handle
+        dir.iter_handle = handle
         data_to_entry(data)
       else
         error = WinError.value
@@ -38,7 +39,7 @@ module Crystal::System::Dir
       end
     else
       # Use FindNextFile
-      if LibC.FindNextFileW(dir.handle, out data_) != 0
+      if LibC.FindNextFileW(dir.iter_handle, out data_) != 0
         data_to_entry(data_)
       else
         error = WinError.value
@@ -64,31 +65,49 @@ module Crystal::System::Dir
   end
 
   def self.info(dir : DirHandle, path) : ::File::Info
-    if dir.handle == LibC::INVALID_HANDLE_VALUE
-      handle = LibC.FindFirstFileW(dir.query, out data)
-      begin
-        Crystal::System::FileDescriptor.system_info handle, LibC::FILE_TYPE_DISK
-      ensure
-        close(handle, path) rescue nil
+    if dir.file_handle == LibC::INVALID_HANDLE_VALUE
+      handle = LibC.CreateFileW(
+        System.to_wstr(path),
+        LibC::FILE_READ_ATTRIBUTES,
+        LibC::FILE_SHARE_READ | LibC::FILE_SHARE_WRITE | LibC::FILE_SHARE_DELETE,
+        nil,
+        LibC::OPEN_EXISTING,
+        LibC::FILE_FLAG_BACKUP_SEMANTICS,
+        LibC::HANDLE.null,
+      )
+
+      if handle == LibC::INVALID_HANDLE_VALUE
+        raise ::File::Error.from_winerror("Unable to get directory info", file: path)
       end
-    else
-      Crystal::System::FileDescriptor.system_info dir.handle, LibC::FILE_TYPE_DISK
+
+      dir.file_handle = handle
     end
+
+    Crystal::System::FileDescriptor.system_info dir.file_handle, LibC::FILE_TYPE_DISK
   end
 
   def self.close(dir : DirHandle, path : String) : Nil
-    close(dir.handle, path)
-    dir.handle = LibC::INVALID_HANDLE_VALUE
+    close_iter(dir.iter_handle, path)
+    close_file(dir.file_handle, path)
+    dir.iter_handle = dir.file_handle = LibC::INVALID_HANDLE_VALUE
   end
 
-  def self.close(handle : LibC::HANDLE, path : String) : Nil
+  private def self.close_iter(handle : LibC::HANDLE, path : String) : Nil
     return if handle == LibC::INVALID_HANDLE_VALUE
 
     if LibC.FindClose(handle) == 0
       raise ::File::Error.from_winerror("Error closing directory", file: path)
     end
   end
 
+  private def self.close_file(handle : LibC::HANDLE, path : String) : Nil
+    return if handle == LibC::INVALID_HANDLE_VALUE
+
+    if LibC.CloseHandle(handle) == 0
+      raise ::File::Error.from_winerror("CloseHandle", file: path)
+    end
+  end
+
   def self.current : String
     System.retry_wstr_buffer do |buffer, small_buf|
       len = LibC.GetCurrentDirectoryW(buffer.size, buffer)