[raster] ST_SummaryStats should return null stats on nodata rasters

[pracine]

SELECT ST_SummaryStats(ST_AddBand(ST_MakeEmptyRaster(10, 10, 0, 0, 1, 1, 0, 0, 4326), '16BSI'::text, 0, 0));

returns:

"(0,0,0,-1,0,0)"

If zero pixel were taken into account in the stats, then there should be no results for the other metrics. If I fetch only the min, the max, or the average, how do I know there are actually not significant? It should return:

"(0,null,null,null,null,null)"

[dustymugs]

robe, can I make this change to 2.0? Or only in trunk (2.1)?

[robe]

hmm -- your and Pierre's call I would say. Technically I guess you could say its a change in behavior but then if you say the behavior was a bug in the first place, then its a bug fix and can go in 2.0.1 as long its not an invasive change that risks breaking something else.

[dustymugs]

Bug it is!

[dustymugs]

Fixed in r9931. Still need to commit changes for trunk.

[dustymugs]

Fixed in r9943 for trunk.