gdalwarp with proj pipeline does not write CRS to header

[bpurinton]

Expected behavior and actual behavior.

Running this command:

gdalwarp -s_srs EPSG:32603 -t_srs EPSG:6393 source_epsg32603.tif dest_epsg6393.tif

And this command:

gdalwarp -ct "+proj=pipeline +step +inv +proj=utm +zone=3 +ellps=WGS84 +step +proj=aea +lat_0=50 +lon_0=-154 +lat_1=55 +lat_2=65 +x_0=0 +y_0=0 +ellps=GRS80" source_epsg32603.tif dest_epsg6393.tif

(with the proj pipeline passed to -ct gathered from this command:

projinfo -s EPSG:32603 -t EPSG:6393 -o PROJ --hide-ballpark --spatial-test intersects

)

Should produce the same results.

They do produce the same GeoTiff; but in the second command with the ct pipeline; the CRS info is not written to the dest_*.tif header.

Am I misusing the -ct flag? Or should these equivalent operations produce the same output, including the correct CRS info in the dest_*.tif header when I run a gdalinfo?

Operating system

macOS 13.4.1

GDAL version and provenance

GDAL 3.6.4, released 2023/04/17 installed via brew install gdal

[rouault]

@bpurinton #8243 should clarify the usage