[construction.t] Added tests for an unreported bug fixed in Rakudo 03…

…7775e.

S12-construction/construction.t

@@ -2,7 +2,7 @@ use v6;
 
 use Test;
 
-plan 15;
+plan 19;
 
 # L<S12/"Construction and Initialization">
 
@@ -66,6 +66,18 @@ is Foo.new("a string").a, 'a string', "our own 'new' was called";
   is $foo.x[0], 3, "... and keeps its value properly."
 }	
 
+# Test for a bug fixed in Rakudo 037775eb.
+{
+    class SeqAttr { has $.x };
+    my $f = { SeqAttr.new: :$^x };
+
+    my $o = $f(<a b>);
+    isa_ok $o, SeqAttr, 'Created SeqAttr object';
+    isa_ok $o.x, Seq, '...with a Seq attribute';
+    is ($o.x)[0], 'a', '...with the right first element';
+    is ($o.x)[1], 'b', '...and the right second element.';
+}
+
 # RT #64116
 {
     class RT64116 { has %.env is rw };