Memtx MVCC does not respect collation-based and MsgPack equivalence classes #11292
Description
This code assumes that equivalence classes of keys are defined by the MsgPack encoding:
Lines 362 to 372 in 23d4771
However, this is not true for collation-based comparisons, and this is also not true for suboptimal MsgPack encodings (#9965).
Steps to reproduce
os.execute('rm -rf *.snap *.xlog *.vylog 512')
local log = require('log')
local txn_proxy = require('test.box.lua.txn_proxy')
box.cfg{memtx_use_mvcc_engine = true}
box.schema.space.create('s'):create_index('p')
box.schema.space.create('c'):create_index('p', {parts = {{1, 'str', collation = 'unicode_ci'}}})
local tx1 = txn_proxy:new()
local tx2 = txn_proxy:new()
local tx3 = txn_proxy:new()
tx1:begin()
tx2:begin()
tx3:begin()
log.info(tx1("box.space.c:get{'ЁлКа'}"))
log.info(tx1("box.space.s:insert{0}"))
log.info(tx2("box.space.c:get{'ЁЛКа'}"))
log.info(tx1("box.space.s:insert{1}"))
log.info(tx3("box.space.c:insert{'ёлка'}"))
log.info(tx3:commit())
log.info(tx1:commit())
log.info(tx2:commit())
os.exit()Actual behavior
Only one of tx1 and tx2 gets conflicted.
Expected behavior
Both tx1 and tx2 get conflicted.