[CALCITE-7704] ARRAY_INSERT crashes in code generation with array-of-arrays argument

core/src/main/java/org/apache/calcite/sql/validate/SqlValidatorUtil.java

@@ -1476,14 +1476,18 @@ private static void adjustTypeForArrayFunctions(
             // such as spark array, the SqlKind is other function.
             // however, the name is same for those different array forms.
             && "ARRAY".equals(((SqlBasicCall) operand).getOperator().getName())) {
-          call.setOperand(idx, castArrayElementTo(validator, operand, targetType));
+          RelDataType elementType =
+              arrayOperands ? targetType
+                  : requireNonNull(targetType.getComponentType(),
+                      () -> "componentType of " + targetType);
+          call.setOperand(idx, castArrayElementTo(validator, operand, elementType));
           // The rewrite changes the element types of the array constructor,
           // so the type the validator has recorded for it must change too
           RelDataType priorType = validator.getValidatedNodeTypeIfKnown(operand);
           if (priorType != null) {
             validator.setValidatedNodeType(operand,
                 SqlTypeUtil.createArrayType(opBinding.getTypeFactory(),
-                    targetType, priorType.isNullable()));
+                    elementType, priorType.isNullable()));
           }
         } else {
           RelDataType castType = targetType;

testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java

@@ -8358,6 +8358,10 @@ void checkRegexpExtract(SqlOperatorFixture f0, FunctionAlias functionAlias) {
             + "array[cast(3 as double)])",
         "[[1.0, 2.0], [3.0]]",
         "DOUBLE NOT NULL ARRAY NOT NULL ARRAY NOT NULL");
+    // Test case for [CALCITE-7704]
+    // ARRAY_INSERT crashes in code generation with array-of-arrays argument
+    f.checkScalar("array_append(array[array[cast(1 as double)]], array[2])",
+        "[[1.0], [2.0]]", "DOUBLE NOT NULL ARRAY NOT NULL ARRAY NOT NULL");
 
     // element cast to the biggest type
     f.checkScalar("array_append(array(cast(1 as tinyint)), 2)", "[1, 2]",
@@ -8707,6 +8711,10 @@ void checkRegexpExtract(SqlOperatorFixture f0, FunctionAlias functionAlias) {
     f.checkScalar("array_prepend(array_distinct(array[1, 2, 3]), "
             + "cast(4 as double))",
         "[4.0, 1.0, 2.0, 3.0]", "DOUBLE NOT NULL ARRAY NOT NULL");
+    // Test case for [CALCITE-7704]
+    // ARRAY_INSERT crashes in code generation with array-of-arrays argument
+    f.checkScalar("array_prepend(array[array[cast(1 as double)]], array[2])",
+        "[[2.0], [1.0]]", "DOUBLE NOT NULL ARRAY NOT NULL ARRAY NOT NULL");
 
     // element cast to the biggest type
     f.checkScalar("array_prepend(array(1), cast(3 as float))", "[3.0, 1.0]",
@@ -9064,6 +9072,12 @@ void checkArrayReverseFunc(SqlOperatorFixture f0, SqlFunction function,
             + "cast(array[array[1, 2]] as integer array array), 1, "
             + "array[cast(3 as double)])",
         "[[3.0], [1.0, 2.0]]", "DOUBLE NOT NULL ARRAY ARRAY NOT NULL");
+    // Test case for [CALCITE-7704]
+    // ARRAY_INSERT crashes in code generation with array-of-arrays argument
+    f1.checkScalar("array_insert(array[array[cast(1 as double)]], 1, array[2])",
+        "[[2.0], [1.0]]", "DOUBLE NOT NULL ARRAY ARRAY NOT NULL");
+    f1.checkScalar("array_insert(array[array[1]], 1, array[2.5])",
+        "[[2.5], [1.0]]", "DECIMAL(11, 1) NOT NULL ARRAY ARRAY NOT NULL");
 
     f1.checkScalar("array_insert(array[1, 2, 3], 3, 4)",
         "[1, 2, 4, 3]", "INTEGER ARRAY NOT NULL");