Clearing GCPs on TIFF fails

[warmerdam]

Clearing the GCPs on this TIFF file with the following script has no effect. Why?

from osgeo import gdal
vrt_ds = gdal.Open('work.tif',gdal.GA_Update)
vrt_ds.SetGCPs([], '')
vrt_ds = None

$ python clear_gcps.py 
warmerdam@gdal.cmo:~/wrk1
$ gdalinfo work.tif 
Driver: GTiff/GeoTIFF
Files: work.tif
Size is 5, 5
Coordinate System is `'
GCP Projection = 
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
GCP[  0]: Id=1, Info=
          (0.5,0.5) -> (-115.195,32.6336111111111,0)
GCP[  1]: Id=2, Info=
          (11778.5,0.5) -> (-114.318611111111,32.4977777777778,0)
GCP[  2]: Id=3, Info=
          (11778.5,7619.5) -> (-114.443611111111,32.0633333333333,0)
GCP[  3]: Id=4, Info=
          (0.5,7619.5) -> (-115.316111111111,32.1986111111111,0)
...

[Even Rouault]

trunk r29039 "GTiff: fix clearing of GCPs (#5945)"

[Even Rouault]

trunk r29041 "GTiff: Amend previous commit to fix failures in overviewds_3 and vrtwarp_7. The ForceUnset flags can only be set to TRUE in the SetProjection, SetGeoTransform and SetGCPs method, and reset in WriteGeoTIFFInfo() (#5945)"

[Even Rouault]

Milestone renamed