issue: #44909
When requery optimization is enabled, search results contain IDs
but empty FieldsData. During reduce/rerank operations, if the
first shard has empty FieldsData while others have data,
PrepareResultFieldData initializes an empty array, causing
AppendFieldData to panic when accessing array indices.
Changes:
- Find first non-empty FieldsData as template in 3 functions:
reduceAdvanceGroupBy, reduceSearchResultDataWithGroupBy,
reduceSearchResultDataNoGroupBy
- Add length check before 2 AppendFieldData calls in reduce
functions to prevent panic
- Improve newRerankOutputs to find first non-empty fieldData
using len(FieldsData) check instead of GetSizeOfIDs
- Add length check in appendResult before AppendFieldData
- Add comprehensive unit tests for empty and partial empty
FieldsData scenarios in both reduce and rerank functions
This fix handles both pure requery (all empty) and mixed
scenarios (some empty, some with data) without breaking normal
search flow. The key improvement is checking FieldsData length
directly rather than IDs, as requery may have IDs but empty
FieldsData.
Signed-off-by: Wei Liu <wei.liu@zilliz.com>
