drawPaletted(dst0, r, src, sp, false)
				return
			}
		}
	case *image.NRGBA:
		if op == Src && mask == nil {
			if src0, ok := src.(*image.NRGBA); ok {
				d0 := dst0.PixOffset(r.Min.X, r.Min.Y)
				s0 := src0.PixOffset(sp.X, sp.Y)
				drawCopySrc(
					dst0.Pix[d0:], dst0.Stride, r, src0.Pix[s0:], src0.Stride, sp, 4*r.Dx())
				return
			}
		}
	case *image.NRGBA64:

	{"copy", `var src, dst []byte; copy(dst, src)`, `func([]byte, []byte) int`},
	{"copy", `type T [][]int; var src, dst T; _ = copy(dst, src)`, `func(p.T, p.T) int`},
	{"copy", `var src string; var dst []byte; copy(dst, src)`, `func([]byte, string) int`},
	{"copy", `type T string; type U []byte; var src T; var dst U; copy(dst, src)`, `func(p.U, p.T) int`},

	{"copy", `var src, dst []byte; copy(dst, src)`, `func([]byte, []byte) int`},
	{"copy", `type T [][]int; var src, dst T; _ = copy(dst, src)`, `func(p.T, p.T) int`},
	{"copy", `var src string; var dst []byte; copy(dst, src)`, `func([]byte, string) int`},
	{"copy", `type T string; type U []byte; var src T; var dst U; copy(dst, src)`, `func(p.U, p.T) int`},

				}
				continue
			}
		}

		// Move any untransformed source bytes to the start of the buffer
		// and read more bytes.
		if r.src0 != 0 {
			r.src0, r.src1 = 0, copy(r.src, r.src[r.src0:r.src1])
		}
		n, r.err = r.r.Read(r.src[r.src1:])
		r.src1 += n
	}
}

// TODO: implement ReadByte (and ReadRune??).

// Writer wraps another io.Writer by transforming the bytes read.

				}
				continue
			}
		}

		// Move any untransformed source bytes to the start of the buffer
		// and read more bytes.
		if r.src0 != 0 {
			r.src0, r.src1 = 0, copy(r.src, r.src[r.src0:r.src1])
		}
		n, r.err = r.r.Read(r.src[r.src1:])
		r.src1 += n
	}
}

// TODO: implement ReadByte (and ReadRune??).

// Writer wraps another io.Writer by transforming the bytes read.

        collection.withActualValue {
            it.from("src1", "src2")
            it.from("src3")
        }
        then:
        collection.from as List == ["src0", "src1", "src2", "src3"]
        collection.explicit
    }

    def "can incrementally set paths as convention to the collection using from"() {
        when:
        collection.convention("src0")
        collection.from("src1", "src2")

	dst0 := image.NewRGBA(image.Rect(0, 0, 100, 100))
	src0 := image.NewRGBA(image.Rect(0, 0, 100, 100))
	mask0 := image.NewRGBA(image.Rect(0, 0, 100, 100))
	for _, c := range clipTests {
		dst := dst0.SubImage(c.dr).(*image.RGBA)
		src := src0.SubImage(c.sr).(*image.RGBA)
		r, sp, mp := c.r, c.sp, c.mp
		if c.nilMask {
			clip(dst, &r, src, &sp, nil, nil)
		} else {
			clip(dst, &r, src, &sp, mask0.SubImage(c.mr), &mp)
		}

		dst, _ := coreType(x.typ).(*Slice)

		y := args[1]
		src0 := coreString(y.typ)
		if src0 != nil && isString(src0) {
			src0 = NewSlice(universeByte)
		}
		src, _ := src0.(*Slice)

		if dst == nil || src == nil {
			check.errorf(x, InvalidCopy, invalidArg+"copy expects slice arguments; found %s and %s", x, y)
			return
		}

		if !Identical(dst.elem, src.elem) {

		dst, _ := coreType(x.typ).(*Slice)

		y := args[1]
		src0 := coreString(y.typ)
		if src0 != nil && isString(src0) {
			src0 = NewSlice(universeByte)
		}
		src, _ := src0.(*Slice)

		if dst == nil || src == nil {
			check.errorf(x, InvalidCopy, invalidArg+"copy expects slice arguments; found %s and %s", x, y)
			return
		}

		if !Identical(dst.elem, src.elem) {

			t.Fatalf("%s: got %v; want package types", test, pkg)
		}
	}

	f("src0", src0)
	f("src1", src1)
	f("src2", src2)
}

func TestIssue22525(t *testing.T) {
	const src = `package p; func f() { var a, b, c, d, e int }`

	got := "\n"
	conf := Config{Error: func(err error) { got += err.Error() + "\n" }}
	typecheck(src, &conf, nil) // do not crash
	want := "\n" +
		"p:1:27: declared and not used: a\n" +