Virtual bands may compute wrong results for non-zero levels of image pyramids

Reproduce:

(1) Open product in VISAT
(2) Look at raster width (e.g. 1121 pixels)
(3) Add virtual band with band maths expresiion "X" (value of pixel X coordinate)
(4) Look at Colour Manipulation window: min=0, max=139 (Rough statistics!) --> WRONG (corresponds to image level > 0, e.g. 3)
(5) Press "Rough statistics!" label
(6) min=0, max=1120 --> NOW CORRECT (corresponds to image level 0)
(7) Open image view for X, zoom in and out --> different zoom levels show different images (different levels of grey)

Problematic class is org.esa.beam.jai.VirtualBandOpImage which obviously does not take actual source coordinates into account, lines 264 and 276 are wrong: "env.setElemIndex(i + j);"

Check: similar problem might occur if image pyramids are created from bands that store their entire raster data in a buffer (if band.setRasterData(buffer) has been used).