Update of LZW compressed TIFF sometimes fail

[rouault]

When rewriting a LZW tile/strip whose existing size is very close to a multiple of 1024 bytes (and larger than 8192 bytes) with compressed data that is larger, the new data is not placed at the end of the file, causing corruption.

Can be demonstrated with

from osgeo import gdal
import shutil
shutil.copy('to_be_updated_lzw.tif', 'out.tif')
ds = gdal.Open( 'out.tif', gdal.GA_Update)
src_ds = gdal.Open('update_lzw.tif')
ds.WriteRaster(0,0,4096,1,src_ds.ReadRaster())
ds = None
ds = gdal.Open( 'out.tif')
print ds.GetRasterBand(1).Checksum()

input_data.zip