[gdal-dev] FYI - embedding overviews into read only file

[Frank Warmerdam]

Martin,

In general GDAL is very poor about checking read-only vs. read-write
status.  I presume the overviews where in a .ovr file, not in the original
file itself, right?

I will note it is desirable that we can build overviews for files
even if we can only open the files readonly (ie. formats
that don't support update), so I wouldn't want to introduce
careful update permission checking now.

Best regards,
Frank

On Mon, Jan 9, 2012 at 6:03 PM, Martin Chapman <chapmanm at pixia.com> wrote:
> Frank,
>
>
>
> It just dawned on me that yesterday I used the following code to open a
> raster file like so:
>
>
>
> mDataSource = (GDALDataset*) GDALOpen(filePath.c_str(), GA_ReadOnly);
>
>
>
> And then used the GDALDefaultOverviews class to embed some overviews into
> the file.  Shouldn’t the API prevent that if I opened the file as read only?
>  I initialized the default overviews class using the dataset pointer.  I am
> using GDAL 1.8.1. .  I used the BuildOverviews() method of the default
> overviews class to execute the process.
>
>
>
> Best regards
>
> Martin
>
>
>
>
>
>
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