[Users] Suggestion for release-patch

[Frank Loeffler]

On Sun, Jun 20, 2010 at 09:53:40PM +0000, knarf at cct.lsu.edu wrote:
>  Fix error in ppm when using GRHydro_enable_internal_excision == no (which is _not_ the default setting). Thanks go to Christian Ott.

Hi,

I suggest to apply this patch also to the just-released version of
GRHydro.

Here are some details first (if you care to know):

  The old code (now also released) produces bogus data if ppm is
  used and the internal GRHydro-excision is turned off by the parameter
  GRHydro::GRHydro_enable_internal_excision. However, the default is
  to have it on and let the excision mask decide. This works.
  The only reason not to use the internal excision method is to use
  your own. To the best of my knowledge the only other method is
  used by Christian Ott, who got bitten by this bug and who also
  found the specific location of the problem. On the other hand,
  someone might just think it would be a good idea to turn this
  off just because there is no excision happening in their runs.

Now, in short, arguments for applying this to the released version:

- It fixes a severe bug.
- The patch is not big. Reviewing it should not take long.

A reason _not_ to apply it is

- The bug is not triggered with default settings and there is no
  strong reason to change that unless you know what you are doing
  anyway.

As I see it, the reasons to apply this patch out-weight the reason
not to do so.

This is one of (at least) two patches I would like to have discussed at
tomorrows call. (the other being the GetComponent-git-update-patch)

Frank

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