ErikBPF opened a new issue, #5884:
URL: https://github.com/apache/datafusion-comet/issues/5884

   ## Description
   
   Implement Spark-compatible duplicate Parquet sibling-name resolution in the 
native reader, replacing the explicit rejection proposed in PR #5786 for issue 
#5783.
   
   As reported in [the PR 
review](https://github.com/apache/datafusion-comet/pull/5786#pullrequestreview-5187242277),
 Spark's behavior depends on where the duplicate occurs:
   
   - Root group: with `message spark_schema { optional int64 a; optional int64 
a; optional int64 b; }` and one raw row `a=1, a=2, b=3`, an explicit `a bigint` 
read schema returns `[1]` (first child wins).
   - Nested structs: issue #5783 demonstrates last-wins resolution through 
`caseSensitiveParquetFieldMap`.
   
   The native Arrow decoder can combine distinct leaves into one column before 
schema adaptation, multiplying rows or failing with a decoder synchronization 
error. Resolution must select the correct physical leaf before decoding, rather 
than dropping duplicate logical fields afterward.
   
   ## Acceptance criteria
   
   Match Spark results, row counts, and error behavior for root, nested struct, 
array-element, and map-value duplicates using explicit read schemas. Cover case 
sensitivity and field-ID reads; preserve unrelated-column projection, filter 
pruning, and metadata-cache behavior. Replace the scan compatibility limitation 
once supported.
   
   Related: #5783, #5786.
   


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