This is an automated cherry-pick of pingcap#7901

Signed-off-by: ti-chi-bot <ti-community-prow-bot@tidb.io>

dbms/src/Storages/DeltaMerge/RowKeyRange.h

@@ -83,6 +83,46 @@ struct RowKeyValue
         {
             size_t cursor = 0;
             int_value = DB::DecodeInt64(cursor, *value);
+            if (unlikely(value->size() != sizeof(Int64)))
+            {
+                // For int type handle, the standard key enconding format should be t{table_id}_r{handle_value}.
+                // But TiKV may generate region range keys which are not strictly following the standard format.
+                // More concretely, the key may be t{table_id}_r{handle_value} + some other bytes.
+                // We need to adapt the key to the standard format.
+                // For example, the key may be t100_r1000 + 0x00, we need to adapt it to t100_r1001.
+                // This is ok, because
+                //  1) if the key is the start range, then [t100_r1000 + 0x00, xxx) has the same semantics with [t100_r1001, xxx)
+                //  2) if the key is the end range, then [xxx, t100_r1000 + 0x00) also has the same semantics with [xxx, t100_r1001)
+                //
+                // Note if the `int_value` is Int64::max_value,
+                // it is a value generated by tiflash itself to means +inf()(which is RowKeyValue::INT_HANDLE_MAX_KEY).
+                // So we can just ignore it.
+                if (value->size() != sizeof(UInt64) + 1 || value->back() != 0x00)
+                {
+                    LOG_WARNING(
+                        Logger::get(),
+                        "Meet rowkey {} with unexpected encoding format",
+                        Redact::keyToDebugString(value->data(), value->size()));
+                }
+                else
+                {
+                    if (int_value < std::numeric_limits<Int64>::max())
+                    {
+                        LOG_WARNING(
+                            Logger::get(),
+                            "Meet rowkey {} which has an extra zero suffix",
+                            Redact::keyToDebugString(value->data(), value->size()));
+                        int_value = int_value + 1;
+                        WriteBufferFromOwnString ss;
+                        DB::EncodeInt64(int_value, ss);
+                        value = std::make_shared<String>(ss.releaseStr());
+                    }
+                    else
+                    {
+                        // ignore RowKeyValue::INT_HANDLE_MAX_KEY
+                    }
+                }
+            }
         }
     }
 

dbms/src/Storages/DeltaMerge/tests/gtest_key_range.cpp

@@ -98,6 +98,90 @@ TEST(RowKeyRange_test, RedactRangeFromCommonHandle)
     Redact::setRedactLog(false); // restore flags
 }
 
+<<<<<<< HEAD
+=======
+TEST(RowKey, ToNextKeyIntHandle)
+{
+    const auto key = RowKeyValue::fromHandle(20);
+    const auto next = key.toNext();
+    EXPECT_EQ("21", next.toDebugString());
+
+    {
+        const auto expected_next_int = RowKeyValue::fromHandle(21);
+        EXPECT_EQ(0, compare(next.toRowKeyValueRef(), expected_next_int.toRowKeyValueRef()));
+    }
+    {
+        const auto range_keys = std::make_shared<RegionRangeKeys>(
+            RecordKVFormat::genKey(1, 0),
+            RecordKVFormat::genKey(1, 21));
+        const auto range = RowKeyRange::fromRegionRange(
+            range_keys,
+            /* table_id */ 1,
+            /* is_common_handle */ false,
+            /* row_key_column_size */ 1);
+        EXPECT_EQ(0, compare(next.toRowKeyValueRef(), range.getEnd()));
+    }
+    // Note: {20,00} will be regarded as Key=21 in RowKeyRange::fromRegionRange.
+    {
+        auto key_end = RecordKVFormat::genRawKey(1, 20);
+        key_end.push_back(0);
+        auto tikv_key_end = RecordKVFormat::encodeAsTiKVKey(key_end);
+        const auto range_keys = std::make_shared<RegionRangeKeys>(
+            RecordKVFormat::genKey(1, 0),
+            std::move(tikv_key_end));
+        const auto range = RowKeyRange::fromRegionRange(
+            range_keys,
+            /* table_id */ 1,
+            /* is_common_handle */ false,
+            /* row_key_column_size */ 1);
+        EXPECT_EQ(0, compare(next.toRowKeyValueRef(), range.getEnd()));
+    }
+}
+
+TEST(RowKey, ToNextKeyCommonHandle)
+{
+    using namespace std::literals::string_literals;
+
+    const auto key = RowKeyValue(/* is_common_handle */ true, std::make_shared<String>("\xcc\xab"s), 0);
+    const auto next = key.toNext();
+    EXPECT_EQ("CCAB00", next.toDebugString());
+
+    const auto my_next = RowKeyValue(/* is_common_handle */ true, std::make_shared<String>("\xcc\xab\x00"s), 0);
+    EXPECT_EQ(0, compare(my_next.toRowKeyValueRef(), next.toRowKeyValueRef()));
+}
+
+TEST(RowKey, NextIntHandleCompare)
+{
+    auto int_max = RowKeyValue::INT_HANDLE_MAX_KEY;
+    auto int_max_i64 = RowKeyValue::fromHandle(Handle(std::numeric_limits<HandleID>::max()));
+
+    EXPECT_EQ(1, compare(int_max.toRowKeyValueRef(), int_max_i64.toRowKeyValueRef()));
+
+    auto int_max_i64_pnext = int_max_i64.toPrefixNext();
+    EXPECT_EQ(int_max, int_max_i64_pnext);
+    EXPECT_EQ(0, compare(int_max.toRowKeyValueRef(), int_max_i64_pnext.toRowKeyValueRef()));
+    EXPECT_EQ(0, compare(int_max_i64_pnext.toRowKeyValueRef(), int_max.toRowKeyValueRef()));
+
+    auto int_max_i64_next = int_max_i64.toNext();
+    EXPECT_EQ(int_max, int_max_i64_next);
+    EXPECT_EQ(0, compare(int_max.toRowKeyValueRef(), int_max_i64_next.toRowKeyValueRef()));
+    EXPECT_EQ(0, compare(int_max_i64_next.toRowKeyValueRef(), int_max.toRowKeyValueRef()));
+}
+
+TEST(RowKey, NextIntHandleMinMax)
+{
+    auto v0 = RowKeyValue::fromHandle(Handle(1178400));
+    auto v0_next = v0.toNext();
+    auto v1 = RowKeyValue::fromHandle(Handle(1178401));
+
+    EXPECT_EQ(v0, min(v0, v1));
+    EXPECT_EQ(v0, min(v0, v0_next));
+
+    EXPECT_EQ(v1, max(v0, v1));
+    EXPECT_EQ(v1, max(v0, v0_next));
+}
+
+>>>>>>> 7dccf2c76b (fix row key not in standard format (#7901))
 } // namespace tests
 } // namespace DM
 } // namespace DB