Scan of hash index returns the same tuple twice #11354
Description
Discovered with MVCC fuzzing (#5999).
Steps to reproduce
os.execute('rm -rf *.snap *.xlog *.vylog 512 513')
local json = require('json')
local log = require('log')
local txn_proxy = require('test.box.lua.txn_proxy')
box.cfg{memtx_use_mvcc_engine = true}
local tx9 = txn_proxy:new()
local tx10 = txn_proxy:new()
local tx11 = txn_proxy:new()
local tx15 = txn_proxy:new()
local tx16 = txn_proxy:new()
local tx19 = txn_proxy:new()
local tx22 = txn_proxy:new()
local tx24 = txn_proxy:new()
local tx25 = txn_proxy:new()
local tx26 = txn_proxy:new()
local tx31 = txn_proxy:new()
box.schema.space.create('m', {engine = 'memtx'})
box.space.m:create_index('p', {parts = {
{1, 'uint'},
{2, 'uint'}}})
box.space.m:create_index('s1', {parts = {
{3, 'uint', exclude_null = true},
{2, 'uint'}}})
box.space.m:create_index('s2', {parts = {
{1, 'uint'},
{4, 'uint', exclude_null = true}}})
box.space.m:create_index('s3', {parts = {
{3, 'uint', exclude_null = true},
{4, 'uint', exclude_null = true}}})
box.space.m:create_index('s4', {type = 'HASH', parts = {
{1, 'uint'},
{2, 'uint'}}})
box.schema.space.create('v', {engine = 'vinyl'})
box.space.v:create_index('p', {parts = {
{1, 'uint'},
{2, 'uint'}}})
box.space.v:create_index('s1', {parts = {
{3, 'uint', exclude_null = true},
{2, 'uint'}}})
box.space.v:create_index('s2', {parts = { {1, 'uint'},
{4, 'uint', exclude_null = true}}})
box.space.v:create_index('s3', {parts = { {3, 'uint', exclude_null = true},
{4, 'uint', exclude_null = true}}})
box.space.m:drop()
box.space.v:drop()
box.schema.space.create('m', {engine = 'memtx'})
box.space.m:create_index('p', {parts = {
{1, 'uint'},
{2, 'uint'}}})
box.space.m:create_index('s1', {parts = {
{3, 'uint', exclude_null = true},
{2, 'uint'}}})
box.space.m:create_index('s2', {parts = {
{1, 'uint'},
{4, 'uint', exclude_null = true}}})
box.space.m:create_index('s3', {parts = {
{3, 'uint', exclude_null = true},
{4, 'uint', exclude_null = true}}})
box.space.m:create_index('s4', {type = 'HASH', parts = {
{1, 'uint'},
{2, 'uint'}}})
box.schema.space.create('v', {engine = 'vinyl'})
box.space.v:create_index('p', {parts = {
{1, 'uint'},
{2, 'uint'}}})
box.space.v:create_index('s1', {parts = {
{3, 'uint', exclude_null = true},
{2, 'uint'}}})
box.space.v:create_index('s2', {parts = { {1, 'uint'},
{4, 'uint', exclude_null = true}}})
box.space.v:create_index('s3', {parts = { {3, 'uint', exclude_null = true},
{4, 'uint', exclude_null = true}}})
tx11('box.begin()') -- null
tx22('box.begin()') -- null
tx10('box.begin()') -- null
tx9('box.begin()') -- null
tx9('box.space.m:upsert({2, 4, 5, 3}, {{"=", 3, 8}, {"=", 4, box.NULL}})') -- null
tx19('box.begin()') -- null
tx19('box.space.m:upsert({6, 1, 2, 5}, {{"=", 3, 4}, {"=", 4, box.NULL}})') -- null
tx26('box.begin()') -- null
tx26('box.space.m:insert{8, 6, 6, 7}') -- [8,6,6,7]
tx31('box.begin()') -- null
tx25('box.begin()') -- null
tx26('box.commit()') -- null
tx24('box.begin()') -- null
tx24('box.space.m:replace{7, 7, 4, 1}') -- [7,7,4,1]
tx15('box.begin()') -- null
tx15('box.space.m:replace{5, 5, box.NULL, 6}') -- [5,5,null,6]
tx10('box.space.m:insert{1, 3, 6, 6}') -- [1,3,6,6]
tx16('box.begin()') -- null
tx22('box.space.m:upsert({3, 8, 4, 7}, {{"=", 3, 1}, {"=", 4, 1}})') -- null
tx16('box.space.m:insert{2, 1, 3, 5}') -- [2,1,3,5]
tx24('box.space.m:upsert({7, 8, 7, 4}, {{"=", 3, 8}, {"=", 4, 6}})') -- null
tx24('box.commit()') -- null
tx15('box.space.m:upsert({6, 8, 1, box.NULL}, {{"=", 3, 1}, {"=", 4, 5}})') -- null
tx25('box.space.m:upsert({8, 5, 6, 4}, {{"=", 3, box.NULL}, {"=", 4, 3}})') -- null
tx31('box.space.m:upsert({6, 7, 3, box.NULL}, {{"=", 3, 5}, {"=", 4, 4}})') -- null
tx31('box.commit()') -- null
tx25('box.commit()') -- null
tx10('box.rollback()') -- null
tx22('box.space.m:upsert({1, 8, 5, 2}, {{"=", 3, 6}, {"=", 4, 1}})') -- null
tx22('box.commit()') -- null
tx15('box.rollback()') -- null
tx19('box.rollback()') -- null
tx16('box.rollback()') -- null
tx9('box.rollback()') -- null
log.info(json.encode(tx11('box.space.m.index[4]:select({}, {fullscan = true})'))) -- [[6,7,3,null],[8,6,6,7],[2,6,1,2],[1,8,5,2],[8,3,7,1],[7,7,4,1],[3,8,4,7],[8,5,6,4],[7,8,7,4],[6,7,3,null]]
os.exit()Actual behavior
I> [[[1,8,5,2],[8,6,6,7],[7,7,4,1],[3,8,4,7],[6,7,3,null],[7,8,7,4],[6,7,3,null],[8,5,6,4]]]I.e., tuple [6,7,3,null] is returned twice.
Expected behavior
No tuples are returned twice.