Fix named struct dataType null field names [databricks]

sql-plugin/src/main/scala/org/apache/spark/sql/rapids/complexTypeCreator.scala

@@ -29,6 +29,7 @@ import org.apache.spark.sql.catalyst.analysis.FunctionRegistry.FUNC_ALIAS
 import org.apache.spark.sql.catalyst.expressions.{EmptyRow, Expression, NamedExpression}
 import org.apache.spark.sql.catalyst.util.TypeUtils
 import org.apache.spark.sql.internal.SQLConf
+import org.apache.spark.sql.rapids.shims.CreateNamedStructShims
 import org.apache.spark.sql.types.{ArrayType, DataType, MapType, Metadata, NullType, StringType, StructField, StructType}
 import org.apache.spark.sql.vectorized.ColumnarBatch
 
@@ -205,7 +206,7 @@ case class GpuCreateNamedStruct(children: Seq[Expression]) extends GpuExpression
           case ne: NamedExpression => ne.metadata
           case _ => Metadata.empty
         }
-        StructField(name.toString, expr.dataType, expr.nullable, metadata)
+        StructField(CreateNamedStructShims.fieldName(name), expr.dataType, expr.nullable, metadata)
     }
     StructType(fields)
   }

sql-plugin/src/main/spark330/scala/org/apache/spark/sql/rapids/shims/CreateNamedStructShims.scala

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2026, NVIDIA CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*** spark-rapids-shim-json-lines
+{"spark": "330"}
+{"spark": "330db"}
+{"spark": "331"}
+{"spark": "332"}
+{"spark": "332db"}
+{"spark": "333"}
+{"spark": "334"}
+{"spark": "340"}
+{"spark": "341"}
+{"spark": "341db"}
+{"spark": "342"}
+{"spark": "343"}
+{"spark": "344"}
+{"spark": "350"}
+{"spark": "350db143"}
+{"spark": "351"}
+{"spark": "352"}
+{"spark": "353"}
+{"spark": "354"}
+{"spark": "355"}
+{"spark": "356"}
+{"spark": "357"}
+{"spark": "358"}
+{"spark": "400"}
+{"spark": "400db173"}
+{"spark": "401"}
+{"spark": "402"}
+{"spark": "403"}
+{"spark": "411"}
+{"spark": "412"}
+spark-rapids-shim-json-lines ***/
+
+package org.apache.spark.sql.rapids.shims
+
+object CreateNamedStructShims {
+  def fieldName(name: Any): String = name.toString
+}

sql-plugin/src/main/spark404/scala/org/apache/spark/sql/rapids/shims/CreateNamedStructShims.scala

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2026, NVIDIA CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*** spark-rapids-shim-json-lines
+{"spark": "404"}
+{"spark": "413"}
+{"spark": "420"}
+spark-rapids-shim-json-lines ***/
+
+package org.apache.spark.sql.rapids.shims
+
+object CreateNamedStructShims {
+  def fieldName(name: Any): String = if (name == null) null else name.toString
+}

sql-plugin/src/test/spark330/scala/org/apache/spark/sql/rapids/GpuCreateNamedStructSuite.scala

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2026, NVIDIA CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*** spark-rapids-shim-json-lines
+{"spark": "330"}
+{"spark": "330db"}
+{"spark": "331"}
+{"spark": "332"}
+{"spark": "332db"}
+{"spark": "333"}
+{"spark": "334"}
+{"spark": "340"}
+{"spark": "341"}
+{"spark": "341db"}
+{"spark": "342"}
+{"spark": "343"}
+{"spark": "344"}
+{"spark": "350"}
+{"spark": "350db143"}
+{"spark": "351"}
+{"spark": "352"}
+{"spark": "353"}
+{"spark": "354"}
+{"spark": "355"}
+{"spark": "356"}
+{"spark": "357"}
+{"spark": "358"}
+{"spark": "400"}
+{"spark": "400db173"}
+{"spark": "401"}
+{"spark": "402"}
+{"spark": "403"}
+{"spark": "411"}
+{"spark": "412"}
+spark-rapids-shim-json-lines ***/
+
+package org.apache.spark.sql.rapids
+
+import com.nvidia.spark.rapids.{FQSuiteName, GpuLiteral}
+import org.scalatest.funsuite.AnyFunSuite
+
+import org.apache.spark.sql.types.{IntegerType, StringType}
+
+class GpuCreateNamedStructSuite extends AnyFunSuite with FQSuiteName {
+  test("dataType follows legacy Spark behavior for a null field name") {
+    val struct = GpuCreateNamedStruct(Seq(
+      GpuLiteral.create(null, StringType),
+      GpuLiteral.create(1, IntegerType)))
+
+    intercept[NullPointerException] {
+      struct.dataType
+    }
+    assert(struct.checkInputDataTypes().isFailure)
+  }
+}

sql-plugin/src/test/spark404/scala/org/apache/spark/sql/rapids/GpuCreateNamedStructSuite.scala

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2026, NVIDIA CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*** spark-rapids-shim-json-lines
+{"spark": "404"}
+{"spark": "413"}
+{"spark": "420"}
+spark-rapids-shim-json-lines ***/
+
+package org.apache.spark.sql.rapids
+
+import com.nvidia.spark.rapids.{FQSuiteName, GpuLiteral}
+import org.scalatest.funsuite.AnyFunSuite
+
+import org.apache.spark.sql.types.{IntegerType, StringType}
+
+class GpuCreateNamedStructSuite extends AnyFunSuite with FQSuiteName {
+  test("dataType is null-safe for a null field name") {
+    val struct = GpuCreateNamedStruct(Seq(
+      GpuLiteral.create(null, StringType),
+      GpuLiteral.create(1, IntegerType)))
+    val dataType = struct.dataType
+
+    assert(dataType.length === 1)
+    assert(dataType.head.name === null)
+    assert(dataType.head.dataType === IntegerType)
+    assert(dataType.head.nullable === false)
+    assert(struct.checkInputDataTypes().isFailure)
+  }
+}