return
	}

	// bail if file is not zip
	if err == ErrFormat {
		return
	}

	// bail here if no Files expected to be tested
	// (there may actually be files in the zip, but we don't care)
	if zt.File == nil {
		return
	}

	if z.Comment != zt.Comment {
		t.Errorf("comment=%q, want %q", z.Comment, zt.Comment)
	}
	if len(z.File) != len(zt.File) {

const (
	// Type '0' indicates a regular file.
	TypeReg = '0'

	// Deprecated: Use TypeReg instead.
	TypeRegA = '\x00'

	// Type '1' to '6' are header-only flags and may not have a data body.
	TypeLink    = '1' // Hard link
	TypeSymlink = '2' // Symbolic link
	TypeChar    = '3' // Character device node
	TypeBlock   = '4' // Block device node
	TypeDir     = '5' // Directory
	TypeFifo    = '6' // FIFO node

	// Type '7' is reserved.

</pre>

<!--
These conversions also apply to type parameters with suitable core types.
Determine if we can simply use core type instead of underlying type here,
of if the general conversion rules take care of this.
-->

<p>
A <code>Pointer</code> is a <a href="#Pointer_types">pointer type</a> but a <code>Pointer</code>
value may not be <a href="#Address_operators">dereferenced</a>.

}

var listCache sync.Map // map[string]listImports, keyed by contextName

// listSem is a semaphore restricting concurrent invocations of 'go list'. 'go
// list' has its own internal concurrency, so we use a hard-coded constant (to
// allow the I/O-intensive phases of 'go list' to overlap) instead of scaling
// all the way up to GOMAXPROCS.
var listSem = make(chan semToken, 2)

type semToken struct{}

			Name:     "sticky.txt",
			Mode:     0600 | c_ISVTX,
			Size:     7,
			ModTime:  time.Unix(1360602540, 0),
			Typeflag: TypeReg,
		},
		fm: 0600 | fs.ModeSticky,
	}, {
		// hard link.
		h: &Header{
			Name:     "hard.txt",
			Mode:     0644,
			Size:     0,
			Linkname: "file.txt",
			ModTime:  time.Unix(1360600916, 0),
			Typeflag: TypeLink,
		},
		fm: 0644,
	}, {
		// More information.

			testWrite{"hello\n", 6, nil},
			testClose{nil},
		},
	}, {
		// This file was produced using GNU tar v1.26:
		//	echo "Slartibartfast" > file.txt
		//	ln file.txt hard.txt
		//	tar -b 1 --format=ustar -c -f hardlink.tar file.txt hard.txt
		file: "testdata/hardlink.tar",
		tests: []testFnc{
			testHeader{Header{
				Typeflag: TypeReg,
				Name:     "file.txt",
				Size:     15,
				Mode:     0644,

allowing a racing thread to read 1 as well.
</p>

<p>
Note that all these optimizations are permitted in C/C++ compilers:
a Go compiler sharing a back end with a C/C++ compiler must take care
to disable optimizations that are invalid for Go.
</p>

<p>
Note that the prohibition on introducing data races
does not apply if the compiler can prove that the races