// descriptors and should account for either case when reading
	// ZIP files to ensure compatibility."
	//
	// dataDescriptorLen includes the size of the signature but
	// first read just those 4 bytes to see if it exists.
	if _, err := io.ReadFull(r, buf[:4]); err != nil {
		return err
	}
	off := 0
	maybeSig := readBuf(buf[:4])
	if maybeSig.uint32() != dataDescriptorSignature {
		// No data descriptor signature. Keep these four

func mustHaveSwigOnce(t *testing.T) {
	swig, err := exec.LookPath("swig")
	if err != nil {
		t.Skipf("swig not in PATH: %s", err)
	}

	// Check that swig was installed with Go support by checking
	// that a go directory exists inside the swiglib directory.
	// See https://golang.org/issue/23469.
	output, err := exec.Command(swig, "-go", "-swiglib").Output()
	if err != nil {
		t.Skip("swig is missing Go support")
	}

			if window > len(b[i:]) {
				window = len(b[i:])
			}
			// Fill the window with non-match
			for j := 0; j < window; j++ {
				b[i+j] = byte(100)
			}
			// Try to find something that doesn't exist
			p := Count(b[i:i+window], []byte{0})
			if p != 0 {
				t.Errorf("TestCountByteNoMatch(%q, 0) = %d", b[i:i+window], p)
			}
			for j := 0; j < window; j++ {
				b[i+j] = byte(0)
			}
		}
	}
}

// license that can be found in the LICENSE file.

package tar

import (
	"bytes"
	"fmt"
	"strconv"
	"strings"
	"time"
)

// hasNUL reports whether the NUL character exists within s.
func hasNUL(s string) bool {
	return strings.Contains(s, "\x00")
}

// isASCII reports whether the input is an ASCII C-style string.
func isASCII(s string) bool {
	for _, c := range s {

			paxHdrs[paxSchilyXattr+k] = v
		}
		whyOnlyPAX = "only PAX supports Xattrs"
		format.mayOnlyBe(FormatPAX)
	}
	if len(h.PAXRecords) > 0 {
		for k, v := range h.PAXRecords {
			switch _, exists := paxHdrs[k]; {
			case exists:
				continue // Do not overwrite existing records
			case h.Typeflag == TypeXGlobalHeader:
				paxHdrs[k] = v // Copy all records
			case !basicKeys[k] && !strings.HasPrefix(k, paxGNUSparse):

// If the command exits with a non-zero exit status, runGcc prints
// details about what was run and exits.
// Otherwise runGcc returns the data written to standard output and standard error.
// Note that for some of the uses we expect useful data back
// on standard error, but for those uses gcc must still exit 0.
func runGcc(stdin []byte, args []string) (string, string) {

may include command line options.

The cgo tool will always invoke the C compiler with the source file's
directory in the include path; i.e. -I${SRCDIR} is always implied. This
means that if a header file foo/bar.h exists both in the source
directory and also in the system include directory (or some other place
specified by a -I flag), then "#include <foo/bar.h>" will always find the
local version in preference to any other version.

			for _, c := range blk {
				if c == '\n' {
					cntNewline++
				}
			}
		}
		return nil
	}

	// nextToken gets the next token delimited by a newline. This assumes that
	// at least one newline exists in the buffer.
	nextToken := func() string {
		cntNewline--
		tok, _ := buf.ReadString('\n')
		return strings.TrimRight(tok, "\n")
	}

	// Parse for the number of entries.

	if !strings.Contains(f, "(") {
		return f
	}
	return spaceParensRx.ReplaceAllString(f, "")
}

// portRemoved reports whether the given port-specific API feature is
// okay to no longer exist because its port was removed.
func portRemoved(feature string) bool {
	return strings.Contains(feature, "(darwin-386)") ||
		strings.Contains(feature, "(darwin-386-cgo)")
}