Created attachment 31351 [details] thumbnail get tag patch As described in http://poi.apache.org/hpsf/thumbnails.html tag value must be -1, -2 ,-3 or 0l bu on lines 205 and 237 of org.apache.poi.hpsf.Thumbnail : long clipboardFormatTag = LittleEndian.getUInt(getThumbnail(), OFFSET_CFTAG); Must be LittleEndian.getInt() FF FF FF FF will be intepreted as -1 as expected, not ‘4294967295’.
Your patch seems to be missing the file test-data/hpsf/TestThumbnail.xls - we have the metadata of it, but not the contents... Any chance you could attach that file? We can then apply the patch!
Created attachment 31571 [details] sample file test Here's TestThumbnail.xls Thanks
Thanks for the patch and file, applied (with minor tweaks) in r1613256.