n:            27,
			want:         26,
			wantErr:      io.EOF,
			wantBuffered: 0,
		},
		// Any error from filling shouldn't show up until we
		// get past the valid bytes. Here we return 5 valid bytes at the same time
		// as an error, but test that we don't see the error from Discard.
		{
			name: "fill error, discard less",

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package cgotest

// Test that we have no more than one build ID.  In the past we used
// to generate a separate build ID for each package using cgo, and the
// linker concatenated them all.  We don't want that--we only want
// one.

import (
	"bytes"
	"debug/elf"
	"os"
	"testing"
)

		}
		return subdir, true, nil
	}

	for _, p := range filepath.SplitList(build.Default.GOPATH) {
		pabs, err := filepath.EvalSymlinks(p)
		if err != nil {
			return "", false, err
		}
		if !strings.HasPrefix(cwd, pabs) {
			continue
		}
		subdir, err := filepath.Rel(pabs, cwd)
		if err == nil {
			return subdir, false, nil
		}
	}
	return "", false, fmt.Errorf(

	b := make([]byte, n+1)
	for _, len := range lengths {
		// randomish but deterministic data. No 0 or 255.
		for i := 0; i < len; i++ {
			a[i] = byte(1 + 31*i%254)
			b[i] = byte(1 + 31*i%254)
		}
		// data past the end is different
		for i := len; i <= n; i++ {
			a[i] = 8
			b[i] = 9
		}
		cmp := Compare(a[:len], b[:len])
		if cmp != 0 {
			t.Errorf(`CompareIdentical(%d) = %d`, len, cmp)
		}
		if len > 0 {

// The bytes written matches the number of remaining bytes in the current file.
//
// If the current file is sparse and w is an io.WriteSeeker,
// then writeTo uses Seek to skip past holes defined in Header.SparseHoles,
// assuming that skipped regions are filled with NULs.
// This always writes the last byte to ensure w is the right size.
//
// TODO(dsnet): Re-export this when adding sparse file support.