[Mono-bugs] [Bug 32193][Wis] New - bug with arrays, object constructors, and ref types

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Changed by vladimir@pobox.com.

http://bugzilla.ximian.com/show_bug.cgi?id=32193

--- shadow/32193	Sat Oct 12 04:55:03 2002
+++ shadow/32193.tmp.20507	Sat Oct 12 04:55:03 2002
@@ -0,0 +1,121 @@
+Bug#: 32193
+Product: Mono/Runtime
+Version: unspecified
+OS: 
+OS Details: 
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Wishlist
+Component: misc
+AssignedTo: mono-bugs@ximian.com                            
+ReportedBy: vladimir@pobox.com               
+QAContact: mono-bugs@ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: bug with arrays, object constructors, and ref types
+
+Given:
+/*t13.cs*/
+using System;
+
+public class Foo {
+        public static int counter = 0;
+        public int my_counter;
+        public Foo last_foo;
+
+        public Foo () {
+                my_counter = counter++;
+                Console.WriteLine (" Foo: my_counter = " + my_counter);
+        }
+
+        public Foo (ref Foo last)
+                : this ()
+        {
+                last_foo = last;
+                if (last_foo == null) {
+                        Console.WriteLine ("  with null last_foo!");
+                } else {
+                        Console.WriteLine ("  with reference to " +
+last_foo.my_counter);
+                }
+        }
+
+        ~Foo () {
+                Console.WriteLine ("~Foo: my_counter = " + my_counter);
+        }
+
+        public string LastFrob () {
+                if (last_foo != null) {
+                        return last_foo.Frob ();
+                } else {
+                        return "!";
+                }
+        }
+
+        public string Frob () {
+                return "#" + my_counter + " " + LastFrob ();
+        }
+}
+
+public class Driver {
+        public static void Main () {
+                Foo[] foos = new Foo[5];
+
+                Console.WriteLine ("About to create foos");
+
+                for (int i = 0; i < foos.Length; i++) {
+                        if (i != 0)
+                                foos[i] = new Foo (ref foos[i-1]);
+                        else
+                                foos[i] = new Foo ();
+                }
+
+                Console.WriteLine (foos[4].Frob ());
+        }
+}
+/*end*/
+
+(Note: may be related to 32192.  Foo class is pretty much the same, except
+with an extra print.)
+
+Expected output (microsoft runtime):
+
+About to create foos
+ Foo: my_counter = 0
+ Foo: my_counter = 1
+  with reference to 0
+ Foo: my_counter = 2
+  with reference to 1
+ Foo: my_counter = 3
+  with reference to 2
+ Foo: my_counter = 4
+  with reference to 3
+#4 #3 #2 #1 #0 !
+~Foo: my_counter = 4
+~Foo: my_counter = 3
+~Foo: my_counter = 2
+~Foo: my_counter = 1
+~Foo: my_counter = 0
+
+mono output:
+About to create foos
+ Foo: my_counter = 0
+ Foo: my_counter = 1
+  with reference to 0
+ Foo: my_counter = 2
+  with null last_foo!
+ Foo: my_counter = 3
+
+Unhandled Exception: System.NullReferenceException: A null value was found
+where an object
+instance was required
+in <0x0007e> 00 .Foo:.ctor (Foo&)
+in <0x000a4> 00 .Driver:Main ()
+
+mint executes correctly.
+
+I can't quite see what's going on here.. executes correctly without the
+ref's.  Same results with both mcs and csc-compiled assemblies.  (Please
+change the summary to something more indicative of what this bug is)