Merge pull request ClickHouse#78982 from Avogar/fix-variant-bad-binary-data

Fix logical error during parsing of bad binary data of Variant column

Author: Avogar

src/DataTypes/Serializations/SerializationVariant.cpp

@@ -738,13 +738,17 @@ void SerializationVariant::deserializeBinary(IColumn & column, ReadBuffer & istr
     {
         col.insertDefault();
     }
-    else
+    else if (global_discr < variants.size())
     {
         auto & variant_column = col.getVariantByGlobalDiscriminator(global_discr);
         variants[global_discr]->deserializeBinary(variant_column, istr, settings);
         col.getLocalDiscriminators().push_back(col.localDiscriminatorByGlobal(global_discr));
         col.getOffsets().push_back(variant_column.size() - 1);
     }
+    else
+    {
+        throw Exception(ErrorCodes::INCORRECT_DATA, "Cannot read value of {}: unexpected discriminator {}", variant_name, UInt64(global_discr));
+    }
 }
 
 namespace

tests/queries/0_stateless/03410_variant_bad_binary_data.reference

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CURDIR"/../shell_config.sh
+
+$CLICKHOUSE_LOCAL -m -q "
+CREATE TABLE tx (c0 Tuple(Map(Variant(DateTime),Variant(Decimal)))) ENGINE = Memory();
+INSERT INTO TABLE tx (c0) FROM INFILE '$CURDIR/data_binary/bad_variant_data.bin' FORMAT RowBinary; -- {clientError INCORRECT_DATA} 
+DROP TABLE tx;
+"