Opened 16 years ago

Closed 16 years ago

#2502 closed defect (fixed)

Failure to read a warped VRT generated with gdalwarp -dstalpha

Reported by: Even Rouault Owned by: Even Rouault
Priority: normal Milestone: 1.6.0
Component: GDAL_Raster Version: unspecified
Severity: normal Keywords: VRT warped
Cc: warmerdam

Description

A warped VRT of a 3-band dataset with -dstalpha option used cannot be read. For example : 

gdalwarp -dstalpha -of VRT rgbsmall.tif rgbsmall_warped.vrt
gdalinfo -checksum rgbsmall_warped.vrt

I/O errors are reported when computing the checksum.

This is due to the fact that GDALWarpDstAlphaMasker calls GDALRasterIO to write the 4th band, but there's no IWriteBlock method implemented in VRTWarpedRasterBand. We just need a dummy implementation of IWriteBlock since the data just needs to be stored in the cache block and it should be safe to rely on it since the IReadBlock has taken the lock on the cached block ! See the commit to follow.

Change History (2)

comment:1 by Even Rouault, 16 years ago

Fixed in trunk in r15021. Test case added in r15022

comment:2 by Even Rouault, 16 years ago

Resolution: → fixed
Status: new → closed
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