[Regression] DTED driver cannot read any more files with VOL or HDR
|Reported by:||Even Rouault||Owned by:||Even Rouault|
This capacity was lost in r11405 for GDAL 1.5.0. For example, for http://download.osgeo.org/gdal/data/dted/l5102.dhm. The strstr to detect the UHL marker doesn't work because of NUL bytes between it and the first bytes of the file.