IO: add a test for sync()

We already had a test which called sync(), but the new test exercises a
much more common scenario.

1 files changed, 10 insertions, 1 deletions

diff --git a/dist/IO/t/io_xs.t b/dist/IO/t/io_xs.t
index 4657088629..c9b8836b32 100644
--- a/dist/IO/t/io_xs.t
+++ b/dist/IO/t/io_xs.t
@@ -11,7 +11,7 @@ BEGIN {
     }
 }
 
-use Test::More tests => 10;
+use Test::More tests => 11;
 use IO::File;
 use IO::Seekable;
 
@@ -36,6 +36,15 @@ $x->setpos(undef);
 ok($!, "setpos(undef) makes errno non-zero");
 
 SKIP:
+{
+    $Config{d_fsync} || $^O eq 'MSWin32'
+        or skip "No fsync", 1;
+
+    ok($x->sync, "sync on a writable handle")
+        or diag "sync(): ", $!;
+}
+
+SKIP:
 { # [perl #64772] IO::Handle->sync fails on an O_RDONLY descriptor
     $Config{d_fsync}
        or skip "No fsync", 1;