[PATCH] Clamp output values to the bounds of the output buffer

[Even Rouault]

Andrey,

attached you'll find a patch for GDALGridCreate() that clamps the value of the dfValue returned by pfnGDALGridMethod() to the validity range of the output type. I'm not sure if this is really needed in real-word situations but I could get out of range output being casted to improper values in the following scenario.

For example, if you have the following test.csv :

WKT,z
POINT(0 0),-32768
POINT(2 2),32767

And you try :

gdal_grid -ot Int16 -a range test.csv grid.tif -l test -zfield z

the expected value is 32767-(-32768)=65535. Without the patch you'd get -32768. With the patch, you get 32767.

[dron]

Even,

Thanks for the patch, clamping is certainly required here. I have applied the slightly modified patch with r18040.

Best regards, Andrey

[dron]

After a bit of thinking on this issue I've used a different approach utilizing the GDALCopyWords() function. See the r18041.

Best regards, Andrey.