Antalya 26.3 Backport of #102628 - Fix LOGICAL_ERROR crash in Parquet reader for nullable columns with filter

src/Processors/Formats/Impl/Parquet/Reader.cpp

@@ -1334,11 +1334,20 @@ void Reader::decodePrimitiveColumn(ColumnChunk & column, const PrimitiveColumnIn
     /// use_filter_in_decoder path reads ALL pages sequentially, so it would crash trying to access
     /// those reset handles. Only use this optimization when reading the whole column chunk
     /// sequentially (no offset index, i.e. data_pages is empty).
+    ///
+    /// Also disabled for nullable columns (need_null_map): the filter-in-decoder path processes
+    /// ALL rows (passing + non-passing) through processDefLevelsForInnermostColumn, so the
+    /// null_map ends up with entries for all rows rather than just filtered rows. Additionally,
+    /// the decoder applies the filter at consecutive encoded-value indices, but with nulls the
+    /// encoded values don't correspond 1:1 to rows (null rows have no encoded values), causing
+    /// the filter to be applied at wrong positions. The standard row-range iteration path
+    /// correctly handles both issues by only reading rows in passing filter ranges.
     const bool use_filter_in_decoder = (column_info.levels.back().rep == 0) &&
         !row_subgroup.filter.filter.empty() &&
         column.page.initialized &&
         !column.page.is_dictionary_encoded &&
-        column.data_pages.empty();
+        column.data_pages.empty() &&
+        !column.need_null_map;
     const size_t subgroup_end_row_idx = row_subgroup.start_row_idx + row_subgroup.filter.rows_total;
 
     if (use_filter_in_decoder)
@@ -1417,7 +1426,9 @@ void Reader::decodePrimitiveColumn(ColumnChunk & column, const PrimitiveColumnIn
     if (subchunk.null_map && !column_info.output_nullable && !options.format.null_as_default)
     {
         const auto & null_map = assert_cast<const ColumnUInt8 &>(*subchunk.null_map).getData();
-        if (memchr(null_map.data(), 0, null_map.size()) != nullptr)
+        /// null_map uses standard ClickHouse convention: 1 = NULL, 0 = NOT NULL.
+        /// Check if any values are null — those can't be inserted into a non-Nullable column.
+        if (memchr(null_map.data(), 1, null_map.size()) != nullptr)
             throw Exception(ErrorCodes::CANNOT_INSERT_NULL_IN_ORDINARY_COLUMN, "Cannot convert NULL value to non-Nullable type for column {}", column_info.name);
         subchunk.null_map = nullptr;
     }

tests/queries/0_stateless/04099_parquet_nullable_null_check_fix.reference

@@ -0,0 +1,14 @@
+--- null_as_default=1 non-nullable ---
+0	
+3	
+6	
+--- nullable output ---
+0	\N
+3	\N
+6	\N
+--- non-nullable null_as_default=0 should error ---
+CANNOT_INSERT_NULL_IN_ORDINARY_COLUMN
+--- non-nullable null_as_default=0 no nulls in file ---
+1	1
+2	2
+4	4

tests/queries/0_stateless/04099_parquet_nullable_null_check_fix.sh

@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+# Tags: no-fasttest
+
+# Regression test for a LOGICAL_ERROR crash in the Parquet V3 native reader:
+#   "Unexpected number of rows in column subchunk 0 1"
+#
+# The bug was an inverted memchr check in Reader.cpp that searched for byte 0
+# (non-null marker) instead of byte 1 (null marker) in the null_map. When ALL
+# values in a filtered subchunk were NULL and the output column was non-nullable
+# with null_as_default disabled, the check incorrectly cleared the null_map
+# instead of throwing CANNOT_INSERT_NULL_IN_ORDINARY_COLUMN. This left the
+# column with 0 rows while rows_pass was 1, causing the assertion failure.
+#
+# Requires V3 native reader (input_format_parquet_use_native_reader_v3 = 1)
+# because the V3 reader applies filter pushdown during reading. The legacy
+# Arrow-based reader reads ALL rows first then casts, giving different behavior.
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CURDIR"/../shell_config.sh
+
+DATA_FILE="${CLICKHOUSE_TEST_UNIQUE_NAME}.parquet"
+DATA_FILE_NO_NULLS="${CLICKHOUSE_TEST_UNIQUE_NAME}_no_nulls.parquet"
+
+# Create a Parquet file with a Nullable(String) column containing NULLs.
+# Every row where id % 3 == 0 has val = NULL.
+$CLICKHOUSE_CLIENT -q "
+    INSERT INTO FUNCTION file('$DATA_FILE', Parquet)
+    SELECT number AS id, if(number % 3 = 0, NULL, toString(number)) AS val
+    FROM numbers(20)
+    SETTINGS output_format_parquet_use_custom_encoder = 0
+"
+
+# Create a second Parquet file with a Nullable(String) column but NO NULLs.
+$CLICKHOUSE_CLIENT -q "
+    INSERT INTO FUNCTION file('$DATA_FILE_NO_NULLS', Parquet)
+    SELECT number AS id, toString(number) AS val
+    FROM numbers(20)
+    SETTINGS output_format_parquet_use_custom_encoder = 0
+"
+
+# 1) Reading with null_as_default=1 (default) — NULLs become empty strings.
+echo "--- null_as_default=1 non-nullable ---"
+$CLICKHOUSE_CLIENT -q "
+    SELECT id, val FROM file('$DATA_FILE', Parquet, 'id UInt64, val String')
+    WHERE id IN (0, 3, 6) ORDER BY id
+    SETTINGS input_format_null_as_default = 1, input_format_parquet_use_native_reader_v3 = 1
+"
+
+# 2) Reading nullable output — NULLs preserved.
+echo "--- nullable output ---"
+$CLICKHOUSE_CLIENT -q "
+    SELECT id, val FROM file('$DATA_FILE', Parquet, 'id UInt64, val Nullable(String)')
+    WHERE id IN (0, 3, 6) ORDER BY id
+    SETTINGS input_format_parquet_use_native_reader_v3 = 1
+"
+
+# 3) Non-nullable with null_as_default=0 and a filter that hits only NULL rows:
+#    should throw CANNOT_INSERT_NULL, NOT crash with LOGICAL_ERROR.
+#    Use head -1 because CI's --send_logs_level=warning can cause the error code
+#    to appear in both a server log line and the exception message.
+echo "--- non-nullable null_as_default=0 should error ---"
+$CLICKHOUSE_CLIENT -q "
+    SELECT id, val FROM file('$DATA_FILE', Parquet, 'id UInt64, val String')
+    WHERE id = 0
+    SETTINGS input_format_null_as_default = 0, input_format_parquet_use_native_reader_v3 = 1
+" 2>&1 | grep -o 'CANNOT_INSERT_NULL_IN_ORDINARY_COLUMN' | head -1
+
+# 4) Non-nullable with null_as_default=0 reading from a file with NO nulls — should succeed.
+#    (Tests that the fix doesn't break the non-null case.)
+echo "--- non-nullable null_as_default=0 no nulls in file ---"
+$CLICKHOUSE_CLIENT -q "
+    SELECT id, val FROM file('$DATA_FILE_NO_NULLS', Parquet, 'id UInt64, val String')
+    WHERE id IN (1, 2, 4) ORDER BY id
+    SETTINGS input_format_null_as_default = 0, input_format_parquet_use_native_reader_v3 = 1
+"