Src bounds checking fails and Transform results in index out of range panics

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Compile the following program

package main

import "image"
import "graphics-go.googlecode.com/hg/graphics"

func main() {

    src := image.NewGray(image.Rect(50,50,60,60))
    dst := image.NewGray(image.Rect(0,0,100,100))
    graphics.I.Transform(dst, src)
}

2. Run it.

What is the expected output? What do you see instead?
Absolutely nothing. Instead I get:

panic: runtime error: index out of range

goroutine 1 [running]:
graphics-go%2egooglecode%2ecom/hg/graphics.binterpRGBA(0xf84001c870, 
0x3200000032, 0xf84001c570, 0x4049400000000000, 0x4049400000000000, ...)
    /Users/gunca/Code/go/src/pkg/graphics-go.googlecode.com/hg/graphics/bilinear.go:104 +0x5e4
graphics-go%2egooglecode%2ecom/hg/graphics.Affine.Transform(0x3ff0000000000000, 
0x0, 0x0, 0x0, 0x3ff0000000000000, ...)
    /Users/gunca/Code/go/src/pkg/graphics-go.googlecode.com/hg/graphics/affine.go:66 +0x348
main.main()
    /Users/gunca/Code/go-rotate/rotate.go:10 +0x144

What version of the product are you using? On what operating system?
hg identify -> d7322ae4d055+ weekly/weekly.2011-09-21
latest graphics-go on Snow Leopard

Original issue reported on code.google.com by Gunchars on 12 Nov 2011 at 1:48