[Mono-bugs] [Bug 75042][Nor] Changed - Struct ctor does not 0 init return value

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Changed by bmaurer at users.sf.net.

http://bugzilla.ximian.com/show_bug.cgi?id=75042

--- shadow/75042	2005-05-25 14:01:59.000000000 -0400
+++ shadow/75042.tmp.29018	2005-05-25 14:06:19.000000000 -0400
@@ -11,13 +11,13 @@
 AssignedTo: mono-bugs at ximian.com                            
 ReportedBy: nazgul at omega.pl               
 QAContact: mono-bugs at ximian.com
 TargetMilestone: ---
 URL: 
 Cc: 
-Summary: Runtime see nonnull value in notinitialized struct field
+Summary: Struct ctor does not 0 init return value
 
 Please fill in this template when reporting a bug, unless you know what you
 are doing.
 Description of Problem:
 The attached program (out.exe) comes from following Nemerle source code
 (just for reference).
@@ -83,6 +83,20 @@
 ------- Additional Comments From bmaurer at users.sf.net  2005-05-25 14:01 -------
 This is a better, IL only, test case.
 
 On mono it gets a SIGTRAP, on .net it runs fine.
 
 I believe the issue is the calling of the ctor for the value type.
+
+------- Additional Comments From bmaurer at users.sf.net  2005-05-25 14:06 -------
+The issue is the code generated for the ctor
+
+00000000 <xxx__ctor>:
+   0:	55                   	push   ebp
+   1:	8b ec                	mov    ebp,esp
+   3:	c9                   	leave  
+   4:	c3                   	ret   
+
+In C#, the def assignment rules are applied to the ctor -- that is,
+all fields of the struct must be assigned a value before control
+returns from the value type ctor. Thus, we would never have noticed if
+the runtime does not 0 init the fields of a struct