}
	if _, err := b.Read(buf); err != nil {
		t.Fatalf("3rd Read with buffer = %v; want nil", err)
	}
	if r.nread != 2 {
		t.Errorf("num reads = %d; want 2", r.nread)
	}
}

// Test for golang.org/issue/5947
func TestWriterReadFromWhileFull(t *testing.T) {
	buf := new(bytes.Buffer)
	w := NewWriterSize(buf, 10)

	// Fill buffer exactly.
	n, err := w.Write([]byte("0123456789"))

not be referenced from Go code; static functions are permitted.

See $GOROOT/cmd/cgo/internal/teststdio and $GOROOT/misc/cgo/gmp for examples. See
"C? Go? Cgo!" for an introduction to using cgo:
https://golang.org/doc/articles/c_go_cgo.html.

CFLAGS, CPPFLAGS, CXXFLAGS, FFLAGS and LDFLAGS may be defined with pseudo
#cgo directives within these comments to tweak the behavior of the C, C++

	Name     string
	Source   func() (r io.ReaderAt, size int64) // if non-nil, used instead of testdata/<Name> file
	Comment  string
	File     []ZipTestFile
	Obscured bool  // needed for Apple notarization (golang.org/issue/34986)
	Error    error // the error that Opening this file should return
}

type ZipTestFile struct {
	Name     string
	Mode     fs.FileMode
	NonUTF8  bool
	ModTime  time.Time
	Modified time.Time

		if !validPAXRecord(k, v) {
			return FormatUnknown, nil, headerError{fmt.Sprintf("invalid PAX record: %q", k+" = "+v)}
		}
	}

	// TODO(dsnet): Re-enable this when adding sparse support.
	// See https://golang.org/issue/22735
	/*
		// Check sparse files.
		if len(h.SparseHoles) > 0 || h.Typeflag == TypeGNUSparse {
			if isHeaderOnlyType(h.Typeflag) {
				return FormatUnknown, nil, headerError{"header-only type cannot be sparse"}

// If the allocation fails, it panics with ErrTooLarge.
func growSlice(b []byte, n int) []byte {
	defer func() {
		if recover() != nil {
			panic(ErrTooLarge)
		}
	}()
	// TODO(http://golang.org/issue/51462): We should rely on the append-make
	// pattern so that the compiler can call runtime.growslice. For example:
	//	return append(b, make([]byte, n)...)
	// This avoids unnecessary zero-ing of the first len(b) bytes of the

			fatalf("reading DWARF entry: %s", err)
		}
		if e == nil {
			break
		}
		switch e.Tag {
		case dwarf.TagVariable:
			name, _ := e.Val(dwarf.AttrName).(string)
			// As of https://reviews.llvm.org/D123534, clang
			// now emits DW_TAG_variable DIEs that have
			// no name (so as to be able to describe the
			// type and source locations of constant strings)
			// like the second arg in the call below:
			//

			Name:       "file4",
			ModTime:    time.Unix(1400000000, 0),
			PAXRecords: map[string]string{"mtime": "1400000000"},
			Format:     FormatPAX,
		}},
	}, {
		file: "testdata/nil-uid.tar", // golang.org/issue/5290
		headers: []*Header{{
			Name:     "P1050238.JPG.log",
			Mode:     0664,
			Uid:      0,
			Gid:      0,
			Size:     14,
			ModTime:  time.Unix(1365454838, 0),
			Typeflag: TypeReg,

		case "linux":
			// Copied from golang.org/x/sys/unix/dev_linux.go.
			major := uint32((dev & 0x00000000000fff00) >> 8)
			major |= uint32((dev & 0xfffff00000000000) >> 32)
			minor := uint32((dev & 0x00000000000000ff) >> 0)
			minor |= uint32((dev & 0x00000ffffff00000) >> 12)
			h.Devmajor, h.Devminor = int64(major), int64(minor)
		case "darwin", "ios":
			// Copied from golang.org/x/sys/unix/dev_darwin.go.

the main variation having to do with addressing modes. Input is
run through a simplified C preprocessor that implements #include,
#define, #ifdef/endif, but not #if or ##.

For more information, see https://golang.org/doc/asm.
*/

// For example, on return:
//
//	w.importMap["math"] = "math"
//	w.importDir["math"] = "<goroot>/src/math"
//
//	w.importMap["golang.org/x/net/route"] = "vendor/golang.org/x/net/route"
//	w.importDir["vendor/golang.org/x/net/route"] = "<goroot>/src/vendor/golang.org/x/net/route"
//
// Since the set of packages that exist depends on context, the result of