Fix watching specific files on windows

When you are only watching specific file paths, you
get change events for all files in the same directory.
On linux only changes to watched files get reported.

Author: mgreter

lib/Filesys/Notify/Simple.pm

@@ -120,6 +120,7 @@ sub mk_wait_win32 {
         my @path = @_;
 
         my $fs = _full_scan(@path);
+        my %watched = map { (Cwd::realpath($_), 1) } @path;
         my (@notify, @fskey);
         for my $path (keys %$fs) {
             my $winpath = $is_cygwin ? Cygwin::posix_to_win_path($path) : $path;
@@ -137,7 +138,28 @@ sub mk_wait_win32 {
                 Carp::croak("Can't wait notifications, maybe ".scalar(@notify)." directories exceeds limitation.") if ! defined $idx;
                 if($idx > 0) {
                     --$idx;
+                    # get all file changes in path
                     my $new_fs = _full_scan($fskey[$idx]);
+                    # process all reported file changes in path
+                    foreach my $root (keys %{$new_fs}) {
+                        # check if we watch particular path
+                        unless (exists $fs->{$root}) {
+                            # remove paths not watched by us
+                            delete $new_fs->{$root};
+                        } else {
+                            foreach my $file (keys %{$new_fs->{$root}}) {
+                                # check if we watch particular file
+                                unless (exists $fs->{$root}->{$file}) {
+                                    # check if we watch the directory
+                                    unless (exists $watched{$root}) {
+                                        # remove files not watched by us
+                                        delete $new_fs->{$root}->{$file};
+                                    }
+                                }
+                            }
+                        }
+                    }
+
                     $notify[$idx]->reset;
                     my $old_fs = +{ map { ($_ => $fs->{$_}) } keys %$new_fs };
                     _compare_fs($old_fs, $new_fs, sub { push @events, { path => $_[0] } });
@@ -210,7 +232,7 @@ sub _full_scan {
 
         # remove root entry
         # NOTE: On MSWin32, realpath and rel2abs disagree with path separator.
-        delete $map{$fp}{File::Spec->rel2abs($fp)};
+        delete $map{$fp}{File::Spec->rel2abs($fp)} if exists $map{$fp};
     }
 
     return \%map;