Tests for reading from $*IN from threads.

Covers RT #124005.

Author: jnthn

S16-io/handles-between-threads.t

@@ -1,7 +1,9 @@
 use v6;
 use Test;
+use lib 't/spec/packages';
+use Test::Util;
 
-plan 6;
+plan 8;
 
 my $filename = $*TMPDIR ~ '/tmp.' ~ $*PID ~ '-' ~ time;
 
@@ -14,3 +16,27 @@ my $rfh = await start { open($filename, :r) };
 is $rfh.get, 'abc', 'Can read handle in main thread opened in another thread';
 is (await start $rfh.get), 'def', 'Can read handle on thread pool';
 lives-ok { $rfh.close }, 'Can close handle on main thread after opening on another thread';
+
+is_run('await start { say $*IN.get.uc for ^3 }',
+       "foo\nbar\nbaz\n",
+       {
+           status => 0,
+           out    => "FOO\nBAR\nBAZ\n",
+           err    => "",
+       },
+       'reading from $*IN from another thread works (file)');
+
+# RT #124005
+{
+    my $temp-file = 'handle-between-threads-' ~ $*PID;
+    spurt $temp-file, "foo";
+    LEAVE unlink $temp-file;
+
+    my $cat = $*DISTRO.is-win ?? 'type' !! 'cat';
+    my $quote = $*DISTRO.is-win ?? '"' !! "'";
+    my $proc = shell(
+        Q:s"$cat $temp-file | $*EXECUTABLE -e $quote await start { say get().uc } $quote",
+        :out);
+    is $proc.out.get, "FOO", 'reading from $*IN from another thread works (pipe)';
+    so $proc.out.close;
+}