[tarantool-patches] [PATCH] Test for LuaJIT fold machinery incorrect behavior

[sergos at tarantool.org]

There's a problem in LuaJIT fold transformations machinery. The test
exposes the wrong behavior and will be used for local temporary fix
in Tarantool repo. Follow up for the problem resolution is planned.

https://github.com/LuaJIT/LuaJIT/issues/505

Follow-up #4376
---
 test/luajit-tap/fold_bug_LuaJIT_505.test.lua | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100755 test/luajit-tap/fold_bug_LuaJIT_505.test.lua

diff --git a/test/luajit-tap/fold_bug_LuaJIT_505.test.lua b/test/luajit-tap/fold_bug_LuaJIT_505.test.lua
new file mode 100755
index 000000000..666a08eaf
--- /dev/null
+++ b/test/luajit-tap/fold_bug_LuaJIT_505.test.lua
@@ -0,0 +1,20 @@
+#!/usr/bin/env tarantool
+
+tap = require('tap')
+
+test = tap.test("505")
+test:plan(1)
+
+-- Test file to demonstrate Lua table hash chain bugs discussed in
+--     https://github.com/LuaJIT/LuaJIT/issues/505
+
+jit.opt.start("hotloop=1")
+for _ = 1, 20 do
+    local value = "abc"
+    local pos_c = string.find(value, "c", 1, true)
+    local value2 = string.sub(value, 1, pos_c - 1)
+    local pos_b = string.find(value2, "b", 2, true)
+    assert(pos_b == 2, "FAIL: position of 'b' is " .. pos_b)
+end
+
+test:ok("PASS")
-- 
2.17.1