panic: runtime error: index out of range

[stevemeier]

Hello,

please excuse if this is not an issue with your code but as a beginner in Golang it seems to me like it could be.

Here is the sample code I run:

package main

import "fmt"
import "github.com/davecgh/go-spew/spew"
import "github.com/agext/levenshtein"

func main () {
	var myparams = levenshtein.NewParams()
	myparams.MinScore(0.92)
	spew.Dump(myparams)

	fmt.Println(levenshtein.Match(`foo`, `foo`, myparams))
	fmt.Println(levenshtein.Match(`foo`, `bar`, myparams))
	fmt.Println(levenshtein.Match(`NetworkManager-glib-0.8.1-5.el6_0.1.i686.rpm`, `gdm-plugin-fingerprint-2.30.4-39.el6.i686.rpm`, myparams))
}

It produces the following output:

(*levenshtein.Params)(0xc000094100)({
 insCost: (int) 1,
 subCost: (int) 1,
 delCost: (int) 1,
 maxCost: (int) 0,
 minScore: (float64) 0.92,
 bonusPrefix: (int) 4,
 bonusScale: (float64) 0.1,
 bonusThreshold: (float64) 0.7
})
1
0
panic: runtime error: index out of range

goroutine 1 [running]:
github.com/agext/levenshtein.Calculate(0xc0000ca000, 0x24, 0x2c, 0xc0000cc000, 0x23, 0x30, 0x5, 0x1, 0x1, 0x1, ...)
	/Users/smeier/go/src/github.com/agext/levenshtein/levenshtein.go:112 +0x8ba
github.com/agext/levenshtein.Match(0x11036f6, 0x2c, 0x11037ff, 0x2d, 0xc000094100, 0x2)
	/Users/smeier/go/src/github.com/agext/levenshtein/levenshtein.go:272 +0x1a8
main.main()
	/Users/smeier/Documents/grabbag/levenshtein_bug.go:14 +0x271
exit status 2

I am running go version go1.12.5 darwin/amd64.

Any help or comments are appreciated.

[alex-alrux]

Hi Steve,

Thanks for finding and reporting this - it does look like a bug. We'll look into it right away and should have a fix within the next couple of days.

[alex-alrux]

Just pushed a fix. I will leave the issue open for now, in case anyone has a related comment (e.g. issue still occurring for them). If no new activity, I will close it in a few days and cut a new patch-version release.

[stevemeier]

Looks good. My full script (not the snippet in the report) no longer crashes and the run-time with MinScore set is now roughly 25% less. Thanks for this quick fix!