[Dune] false accusations

[Martin Nolte]

Dear Christian,

I was indeed assuming that you should at least have tested with gcc-4.3. So
simply return to your version, and run the tests with gcc-4.3.4 (without
optimization). It will compile but, e.g., YaspGrid will produce a segmentation
fault.

For us, the problem occurred in ALUGrid, though, and it took a lot of time to
figure out where the problem originated from. Hadn't Robert mentioned that
something in the EntityPointer changed, we would have looked in ALUGrid for
the bug. Since this is a very central place, we were of the opinion that such
changes need heavy testing.

So, in case you really did the required testing, I apologize for the harshness
of the commit message. There were simply too many commits in the last weeks
that simply couldn't ever have compiled.

Maybe you can explain to me why it might work at all: You are calling the copy
constructor of the entity pointer onto itself, aren't you? Is it safe to
assume that this constructor will not change anything in memory? As far as I
know, the ALUGrid entity pointer holds a pointer to an entity. The entity
pointer's copy constructor then allocates a copy of the entity. Hence, I
assume this technique might cause a memory leak. Can we further assume that it
will be optimized out (otherwise we could really copy the entity pointer and
the cast is not needed)?

Martin

Christian Engwer wrote:
> From the logs:
> 
> ------------------------------------------------------------------------
> r6036 | mnolte | 2009-12-04 16:47:37 +0100 (Fr, 04. Dez 2009) | 4
> Zeilen
> 
> !!!before committing basic changes run make check!!!
> 
> This should simply be natural. It took Andreas, Robert and me 30 minutes to find this bug.
> 
> Dear Martin,
> 
> first of all, I did run the tests and they worked on my machine.
> 
> second, if you revert a patch, you should at least state why it was
> wrong. So, what were the problems you encountered? The version you
> submitted is also wrong and gives bogus results if you allow strict
> aliasing.
> 
> Perhaps you aren't the only one thinking in this world, other people
> do this as well and I submitted this particular version _on purpose_.
> 
> Christian
> 
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-- 
Martin Nolte <nolte at mathematik.uni-freiburg.de>

Universität Freiburg                                   phone: +49-761-203-5642
Abteilung für angewandte Mathematik                    fax:   +49-761-203-5632
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79104 Freiburg, Germany