SAP Note 12517 - Hex zero as ZERO value in extracts (SORT, AT)

Symptom:

Customer inquiry about the semantics of the ABAP/4 statements
SORT, AT NEW, and AT END OF when processing an extracted dataset
when the extract dataset contains fields set to hex zero.

Cause and prerequisites

In extracts, the value hex zero is the same as a ZERO value.

Within extracts, fields set to hex zero
- are always sorted before all occupied fields during a sort,
regardless of the sort sequence (ascending, descending)
- Are always skipped with AT NEW and AT END OF in control break.

Using hex zeros as ZERO values in extracts is especially important
when the data for extraction is read using a multi-level logical
database, and when subordinate segments of that logical database
are not always filled.

Solution
Using hex zero as ZERO values does not work properly when
the extract dataset contains fields that are regularly set to hex zero.
This can occur, for example, with fields of type X, I, or F.

For reasons of compatibility, however, the hex zero handling cannot
be changed at the present time.

Key word: ABAP/4