[petrasovaa]

Registering maps into a relative-time dataset with the documented name|start|end file format silently produced wrong results:

printf 'a|0|1\nb|1|2\n' > maps.txt
t.register type=raster input=test file=maps.txt unit=days
t.rast.list input=test columns=name,start_time,end_time,semantic_label

a|0|None|1
b|1|None|2

The end times were dropped (maps registered as point time instead of intervals) and were instead written as semantic labels — including into the raster metadata in the spatial database, where they persist even after t.remove.

The cause is the three-column disambiguation in register_maps_in_space_time_dataset(): the last column is treated as an end
time only when it parses as a datetime, which can never happen for relative time, so the semantic label branch was unconditional for relative datasets. This is a regression from the band references implementation (a83af32); the input file format documentation still describes the original behavior.

Changes:

• An integer third column is now interpreted as an end time for relative-time datasets; a non-integer remains a semantic label. Absolute-time behavior is unchanged.
• New pytest tests for registering from a file (interval, semantic label, increment, no-dataset, and failure cases for both temporal types).
• Removed test.t.register.raster.file.reltime.sh, an assertion-less relic of the pre-gunittest shell framework that is not executed by any harness; its cases are covered by the new tests.
• Documented how the last column is disambiguated in the semantic labels section of the manual.

Written with the help of Claude Code.