[Issue 765] New: ArrayBoundsError when assigning slice of pointer

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=765

           Summary: ArrayBoundsError when assigning slice of pointer
           Product: D
           Version: 0.178
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Keywords: wrong-code
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla at digitalmars.com
        ReportedBy: fvbommel at wxs.nl


void main() {
    uint* where = (new uint[](5)).ptr;

    // either of these lines will throw an ArrayBoundsError
    // without even accessing an array variable :( (just a pointer)
    where[0 .. 5] = 1;
    where[0 .. 0] = 0;          // not even actually accessing anything!
}
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Error: ArrayBoundsError test.d(6)

This did not happen in DMD 0.173

The only reason I can think of for bounds checks to even be made on pointer
slices are:
* check (upper >= lower)
* check (upper * T.sizeof <= 2**32) (on 32-bit machine) to make sure stuff fits
into memory...

Both of these conditions are definitely satisfied here, so I don't see any
legitimate reason for this to happen...


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