Simple find regexes and some regex cause golang tracebacks

[Kellel]

A simple find with a one letter match

diff --git a/_tests/test.lua b/_tests/test.lua
index 6364aec..0ce8927 100644
--- a/_tests/test.lua
+++ b/_tests/test.lua
@@ -19,6 +19,8 @@ assert(not pcall(re.find, "aaa", "(aaaa"))
 assert(re.find("aaaa", "(b|c)*") == nil)
 a, b, s = re.find("abcd efgh ijk", "i([jk])")
 assert(a == 11 and b == 12 and s == "j")
+a, b = re.find("m", "m")
+assert(a == 1 and b == 0)

And the traceback:

kellen@chewbacca:~/.GOPATH/src/github.com/yuin/gluare$ go test
testing _tests/test.lua
--- FAIL: TestGluaRe (0.00s)
        gluare_test.go:24: runtime error: index out of range
                goroutine 18 [running]:
                github.com/yuin/gopher-lua.(*LState).PCall.func1(0xc4200a9040, 0x5f8c90, 0xc420063e40, 0x0, 0x0, 0x0)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/state.go:1631 +0x7a9
                panic(0x5bbe60, 0x6cdbb0)
                        /usr/lib/go-1.8/src/runtime/panic.go:489 +0x2cf
                github.com/yuin/gluare.reFind(0xc4200a9040, 0x1)
                        /home/kellen/.GOPATH/src/github.com/yuin/gluare/gluare.go:60 +0x59e
                github.com/yuin/gopher-lua.callGFunction(0xc4200a9040, 0x0, 0xc4200d8901)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/vm.go:123 +0x40
                github.com/yuin/gopher-lua.init.3.func26(0xc4200a9040, 0x7c180603, 0xc42012e000, 0x0)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/vm.go:699 +0x40a
                github.com/yuin/gopher-lua.mainLoop(0xc4200a9040, 0xc42012e000)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/vm.go:31 +0xd2
                github.com/yuin/gopher-lua.(*LState).callR(0xc4200a9040, 0x0, 0xffffffffffffffff, 0x0)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/state.go:876 +0x277
                github.com/yuin/gopher-lua.(*LState).Call(0xc4200a9040, 0x0, 0xffffffffffffffff)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/state.go:1610 +0x48
                github.com/yuin/gopher-lua.(*LState).PCall(0xc4200a9040, 0x0, 0xffffffffffffffff, 0x0, 0x6b85e0, 0xc420165000)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/state.go:1671 +0x116
                github.com/yuin/gopher-lua.(*LState).DoFile(0xc4200a9040, 0x5ee248, 0x8, 0x5f8708, 0x2)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/auxlib.go:394 +0xd1
                github.com/yuin/gluare.testScriptDir(0xc420090680, 0xc420063f88, 0x1, 0x1, 0x5ed91f, 0x6)
                        /home/kellen/.GOPATH/src/github.com/yuin/gluare/gluare_test.go:23 +0x2ea
                github.com/yuin/gluare.TestGluaRe(0xc420090680)
                        /home/kellen/.GOPATH/src/github.com/yuin/gluare/gluare_test.go:31 +0x74
                testing.tRunner(0xc420090680, 0x5f8710)
                        /usr/lib/go-1.8/src/testing/testing.go:657 +0x96
                created by testing.(*T).Run
                        /usr/lib/go-1.8/src/testing/testing.go:697 +0x2ca

                stack traceback:
                        [G]: in function 'find'
                        test.lua:22: in main chunk
                        [G]: ?
FAIL
exit status 1
FAIL    github.com/yuin/gluare  0.004s

And an issue with match:

@@ -65,3 +67,5 @@ assert(re.match("hello world", "\\w+", 6) == "world")
 assert(re.match("hello world", "\\w+", -5) == "world")
 a, b = re.match("from=world", "(\\w+)=(\\w+)")
 assert(a == "from" and b == "world")
+a, b, c = re.match("123ab123", "([0-9]+)([a-z]+)([0-9]+)|(bc)([0-9]+)")
+assert (a == "123" and b == "ab" and c == "123")

kellen@chewbacca:~/.GOPATH/src/github.com/yuin/gluare$ go test
testing _tests/test.lua
--- FAIL: TestGluaRe (0.00s)
        gluare_test.go:24: runtime error: slice bounds out of range
                goroutine 5 [running]:
                github.com/yuin/gopher-lua.(*LState).PCall.func1(0xc42008b040, 0x5f8c90, 0xc420063e40, 0x0, 0x0, 0x0)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/state.go:1631 +0x7a9
                panic(0x5bbe60, 0x6cdbc0)
                        /usr/lib/go-1.8/src/runtime/panic.go:489 +0x2cf
                github.com/yuin/gluare.reMatch(0xc42008b040, 0x1)
                        /home/kellen/.GOPATH/src/github.com/yuin/gluare/gluare.go:260 +0x2e9
                github.com/yuin/gopher-lua.callGFunction(0xc42008b040, 0x0, 0x1)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/vm.go:123 +0x40
                github.com/yuin/gopher-lua.init.3.func26(0xc42008b040, 0x7c180803, 0xc42010a000, 0x0)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/vm.go:699 +0x40a
                github.com/yuin/gopher-lua.mainLoop(0xc42008b040, 0xc42010a000)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/vm.go:31 +0xd2
                github.com/yuin/gopher-lua.(*LState).callR(0xc42008b040, 0x0, 0xffffffffffffffff, 0x0)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/state.go:876 +0x277
                github.com/yuin/gopher-lua.(*LState).Call(0xc42008b040, 0x0, 0xffffffffffffffff)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/state.go:1610 +0x48
                github.com/yuin/gopher-lua.(*LState).PCall(0xc42008b040, 0x0, 0xffffffffffffffff, 0x0, 0x6b85e0, 0xc42013f800)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/state.go:1671 +0x116
                github.com/yuin/gopher-lua.(*LState).DoFile(0xc42008b040, 0x5ee248, 0x8, 0x5f8708, 0x2)
                        /home/kellen/.GOPATH/src/github.com/yuin/gopher-lua/auxlib.go:394 +0xd1
                github.com/yuin/gluare.testScriptDir(0xc42006cc30, 0xc420063f88, 0x1, 0x1, 0x5ed91f, 0x6)
                        /home/kellen/.GOPATH/src/github.com/yuin/gluare/gluare_test.go:23 +0x2ea
                github.com/yuin/gluare.TestGluaRe(0xc42006cc30)
                        /home/kellen/.GOPATH/src/github.com/yuin/gluare/gluare_test.go:31 +0x74
                testing.tRunner(0xc42006cc30, 0x5f8710)
                        /usr/lib/go-1.8/src/testing/testing.go:657 +0x96
                created by testing.(*T).Run
                        /usr/lib/go-1.8/src/testing/testing.go:697 +0x2ca

                stack traceback:
                        [G]: in function 'match'
                        test.lua:70: in main chunk
                        [G]: ?
FAIL
exit status 1
FAIL    github.com/yuin/gluare  0.003s

[Kellel]

I moved a slightly different version of this regex from some go code into lua.