Move debug assertion inside loop to remove loop duplication

Author: pepijnve

datafusion/physical-expr/src/expressions/case.rs

@@ -456,21 +456,19 @@ impl ResultBuilder {
 
         match &mut self.state {
             Partial { arrays, indices } => {
-                // This is check is only active for debug config because the callers of this method,
-                // `case_when_with_expr` and `case_when_no_expr`, already ensure that
-                // they only calculate a value for each row at most once.
-                #[cfg(debug_assertions)]
-                for row_ix in row_indices.as_primitive::<UInt32Type>().values().iter() {
-                    if !indices[*row_ix as usize].is_none() {
-                        return internal_err!("Duplicate value for row {}", *row_ix);
-                    }
-                }
-
                 let array_index = PartialResultIndex::try_new(arrays.len())?;
 
                 arrays.push(row_values);
 
                 for row_ix in row_indices.as_primitive::<UInt32Type>().values().iter() {
+                    // This is check is only active for debug config because the callers of this method,
+                    // `case_when_with_expr` and `case_when_no_expr`, already ensure that
+                    // they only calculate a value for each row at most once.
+                    #[cfg(debug_assertions)]
+                    if !indices[*row_ix as usize].is_none() {
+                        return internal_err!("Duplicate value for row {}", *row_ix);
+                    }
+
                     indices[*row_ix as usize] = array_index;
                 }
                 Ok(())