Add a test case for bug [perl #19545]

p4raw-id: //depot/perl@18487

diff --git a/t/op/do.t b/t/op/do.t
index a92a918..b611d0d 100755 (executable)
--- a/t/op/do.t
+++ b/t/op/do.t
@@ -31,7 +31,7 @@ sub ok {
     return $ok;
 }
 
-print "1..21\n";
+print "1..22\n";
 
 # Test do &sub and proper @_ handling.
 $_[0] = 0;
@@ -90,6 +90,10 @@ ok( !$@, "do on a non-existing file, second try"  );
 # 6 must be interpreted as a file name here
 ok( (!defined do 6) && $!, "'do 6' : $!" );
 
+# [perl #19545]
+push @t, ($u = (do {} . "This should be pushed."));
+ok( $#t == 0, "empty do result value" );
+
 END {
     1 while unlink("$$.16", "$$.17", "$$.18");
 }