http://d.puremagic.com/issues/show_bug.cgi?id=1038

           Summary: explicit class cast breakage in 1.007
           Product: D
           Version: 1.007
          Platform: PC
        OS/Version: All
            Status: NEW
          Severity: critical
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla@digitalmars.com
        ReportedBy: default_357-line@yahoo.de


Consider the following code:
import std.stdio;

class A { }
class B : A { }

void main() {
  A test=new B;
  writefln("Test is ", test.toString);
  A test_2=cast(A)(new B);
  writefln("Test 2 is ", test_2.toString);
}

What we would expect to see is "test7.B" twice.
However, what we see is "test7.B" and "test7.A", which of course completely
breaks polymorphism.

The error doesn't appear on 1.005, so it was introduced either in '006 or '007. Greetings --downs


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=1038


fvbommel@wxs.nl changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code




------- Comment #1 from fvbommel@wxs.nl  2007-03-08 05:20 -------
Judging by the disassembled code, it appears "cast(A)(new B)"is compiled as if
it was "new A", it passes the ClassInfo for A instead of that for B to
_d_newclass...

By the way, the same thing happens in GDC[1], so it's most likely an error in the front-end.


[1]: (gdc 0.23, using dmd 1.007), the x86-64 Linux binary from sourceforge.


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=1038





------- Comment #2 from thomas-dloop@kuehne.cn  2007-03-11 06:20 -------
Added to DStress as http://dstress.kuehne.cn/run/c/cast_34_A.d http://dstress.kuehne.cn/run/c/cast_34_B.d


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=1038


thomas-dloop@kuehne.cn changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED




------- Comment #3 from thomas-dloop@kuehne.cn  2007-03-12 01:23 -------
Fixed in DMD-1.009


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