better gofmt formatting:

- first cut a better line breaks in expr lists
- trailing commas and semis printed where we tend to write them
- fixed a couple of minor spacing issues (interface{}, chan<-, map[x]y, x: y)
- removed some formatting flags from gofmt: no need to change default
- removed option to reverse declaration order when printing
- excluded files from test that cause trouble with idempotency test for now

R=rsc
DELTA=497  (364 added, 83 deleted, 50 changed)
OCL=34539
CL=34544

src/cmd/gofmt/gofmt.go

@@ -36,9 +36,6 @@ var (
 	tabwidth = flag.Int("tabwidth", 8, "tab width");
 	rawformat = flag.Bool("rawformat", false, "do not use a tabwriter");
 	usespaces = flag.Bool("spaces", false, "align with blanks instead of tabs");
-	optcommas = flag.Bool("optcommas", false, "print optional commas");
-	optsemis = flag.Bool("optsemis", false, "print optional semicolons");
-	reverse = flag.Bool("reverse", false, "print top-level declarations in reverse order without forward-declarations");
 )
 
 
@@ -111,15 +108,6 @@ func printerMode() uint {
 	if *usespaces {
 		mode |= printer.UseSpaces;
 	}
-	if *optcommas {
-		mode |= printer.OptCommas;
-	}
-	if *optsemis {
-		mode |= printer.OptSemis;
-	}
-	if *reverse {
-		mode |= printer.Reverse;
-	}
 	return mode;
 }
 

src/cmd/gofmt/test.sh

@@ -33,7 +33,10 @@ apply1() {
 	# the following have semantic errors:
 	#   bug039.go | bug040.go
 	# the following are not idempotent at the moment because of comment formatting:
+	# TODO: restructure script so these files are only excluded from idempotency testing
 	comment.go | net.go | powser1.go | powser2.go | bug052.go | simpbool.go | "shift.go" | range.go | \
+	goyacc.go | godoc.go | rpc.go | struct.go | log.go | decimal.go | tabwriter.go | encoder.go | debug.go | \
+	elf.go | meteor-contest.go | elffmt.go | \
 	\
 	test_errors.go | calc.go | method1.go | selftest1.go | func3.go | const2.go | \
 	bug014.go | bug025.go | bug029.go | bug032.go | bug039.go | bug040.go | bug050.go |  bug068.go | \

src/pkg/go/printer/printer.go

@@ -30,9 +30,6 @@ const (
 	GenHTML uint = 1 << iota;  // generate HTML
 	RawFormat;  // do not use a tabwriter; if set, UseSpaces is ignored
 	UseSpaces;  // use spaces instead of tabs for indentation and alignment
-	OptCommas;  // print optional commas
-	OptSemis;  // print optional semicolons
-	Reverse;  // print top-level declarations in reverse order without forward-declarations
 )
 
 
@@ -413,11 +410,6 @@ func (p *printer) flush() {
 // ----------------------------------------------------------------------------
 // Printing of common AST nodes.
 
-func (p *printer) optSemis() bool {
-	return p.mode & OptSemis != 0;
-}
-
-
 // TODO(gri) The code for printing lead and line comments
 //           should be eliminated in favor of reusing the
 //           comment intersperse mechanism above somehow.
@@ -458,22 +450,81 @@ func (p *printer) lineComment(d *ast.CommentGroup) {
 
 
 func (p *printer) identList(list []*ast.Ident) {
+	// convert into an expression list
+	xlist := make([]ast.Expr, len(list));
 	for i, x := range list {
-		if i > 0 {
-			p.print(token.COMMA, blank);
+		xlist[i] = x;
 	}
-		p.expr(x);
+	p.exprList(xlist, commaSep);
+}
+
+
+func (p *printer) stringList(list []*ast.StringLit) {
+	// convert into an expression list
+	xlist := make([]ast.Expr, len(list));
+	for i, x := range list {
+		xlist[i] = x;
 	}
+	p.exprList(xlist, 0);
 }
 
 
-func (p *printer) exprList(list []ast.Expr) {
+type exprListMode uint;
+const (
+	blankStart exprListMode = 1 << iota;  // print a blank before the list
+	commaSep;  // elements are separated by commas
+	commaTerm;  // elements are terminated by comma
+)
+
+
+// Print a list of expressions. If the list spans multiple
+// source lines, the original line breaks are respected.
+func (p *printer) exprList(list []ast.Expr, mode exprListMode) {
+	if len(list) == 0 {
+		return;
+	}
+
+	n := len(list)-1;  // TODO 6g compiler bug - need temporary variable n
+	if list[0].Pos().Line == list[n].Pos().Line {
+		// all list entries on a single line
+		if mode & blankStart != 0 {
+			p.print(blank);
+		}
+		for i, x := range list {
+			if i > 0 {
+				if mode & commaSep != 0 {
+					p.print(token.COMMA);
+				}
+				p.print(blank);
+			}
+			p.expr(x);
+		}
+		return;
+	}
+
+	// list entries span multiple lines;
+	// use source code positions to guide line breaks
+	p.print(+1, formfeed);
+	line := list[0].Pos().Line;
 	for i, x := range list {
+		prev := line;
+		line = x.Pos().Line;
 		if i > 0 {
-			p.print(token.COMMA, blank);
+			if mode & commaSep != 0 {
+				p.print(token.COMMA);
+			}
+			if prev < line {
+				p.print(newline);
+			} else {
+				p.print(blank);
+			}
 		}
 		p.expr(x);
 	}
+	if mode & commaTerm != 0 {
+		p.print(token.COMMA);
+	}
+	p.print(-1, formfeed);
 }
 
 
@@ -521,11 +572,14 @@ func (p *printer) signature(params, result []*ast.Field) {
 func (p *printer) fieldList(lbrace token.Position, list []*ast.Field, rbrace token.Position, isInterface bool) bool {
 	if list == nil {
 		// forward declaration
+		// TODO(gri) remove this logic once godoc doesn't produce field
+		//           lists that resemble forward declarations anymore
 		return false;  // no {}'s
 	}
 
 	if len(list) == 0 {
-		p.print(blank, lbrace, token.LBRACE, rbrace, token.RBRACE);
+		// no blank between keyword and {} in this case
+		p.print(lbrace, token.LBRACE, rbrace, token.RBRACE);
 		return true;  // empty list with {}'s
 	}
 
@@ -579,12 +633,9 @@ func (p *printer) fieldList(lbrace token.Position, list []*ast.Field, rbrace tok
 		lastComment = f.Comment;
 	}
 
-	if p.optSemis() {
 	p.print(token.SEMICOLON);
-	}
 	p.lineComment(lastComment);
-
-	p.print(-1, newline, rbrace, token.RBRACE);
+	p.print(-1, formfeed, rbrace, token.RBRACE);
 
 	return true;  // field list with {}'s
 }
@@ -618,7 +669,7 @@ func (p *printer) expr1(expr ast.Expr, prec1 int) (optSemi bool) {
 
 	case *ast.KeyValueExpr:
 		p.expr(x.Key);
-		p.print(blank, x.Colon, token.COLON, blank);
+		p.print(x.Colon, token.COLON, blank);
 		p.expr(x.Value);
 
 	case *ast.StarExpr:
@@ -652,12 +703,7 @@ func (p *printer) expr1(expr ast.Expr, prec1 int) (optSemi bool) {
 		p.print(x.Value);
 
 	case *ast.StringList:
-		for i, x := range x.Strings {
-			if i > 0 {
-				p.print(blank);
-			}
-			p.expr(x);
-		}
+		p.stringList(x.Strings);
 
 	case *ast.FuncLit:
 		p.expr(x.Type);
@@ -699,16 +745,13 @@ func (p *printer) expr1(expr ast.Expr, prec1 int) (optSemi bool) {
 	case *ast.CallExpr:
 		p.expr1(x.Fun, token.HighestPrec);
 		p.print(x.Lparen, token.LPAREN);
-		p.exprList(x.Args);
+		p.exprList(x.Args, commaSep);
 		p.print(x.Rparen, token.RPAREN);
 
 	case *ast.CompositeLit:
 		p.expr1(x.Type, token.HighestPrec);
 		p.print(x.Lbrace, token.LBRACE);
-		p.exprList(x.Elts);
-		if p.mode & OptCommas != 0 {
-			p.print(token.COMMA);
-		}
+		p.exprList(x.Elts, commaSep | commaTerm);
 		p.print(x.Rbrace, token.RBRACE);
 
 	case *ast.Ellipsis:
@@ -723,10 +766,6 @@ func (p *printer) expr1(expr ast.Expr, prec1 int) (optSemi bool) {
 		p.expr(x.Elt);
 
 	case *ast.StructType:
-		if x.Fields == nil && p.mode & Reverse != 0 && p.level == 0 {
-			// omit top-level forward declarations in reverse mode
-			return true;
-		}
 		p.print(token.STRUCT);
 		optSemi = p.fieldList(x.Lbrace, x.Fields, x.Rbrace, false);
 
@@ -735,15 +774,11 @@ func (p *printer) expr1(expr ast.Expr, prec1 int) (optSemi bool) {
 		p.signature(x.Params, x.Results);
 
 	case *ast.InterfaceType:
-		if x.Methods == nil && p.mode & Reverse != 0 && p.level == 0 {
-			// omit top-level forward declarations in reverse mode
-			return true;
-		}
 		p.print(token.INTERFACE);
 		optSemi = p.fieldList(x.Lbrace, x.Methods, x.Rbrace, true);
 
 	case *ast.MapType:
-		p.print(token.MAP, blank, token.LBRACK);
+		p.print(token.MAP, token.LBRACK);
 		p.expr(x.Key);
 		p.print(token.RBRACK);
 		p.expr(x.Value);
@@ -755,7 +790,7 @@ func (p *printer) expr1(expr ast.Expr, prec1 int) (optSemi bool) {
 		case ast.RECV:
 			p.print(token.ARROW, token.CHAN);
 		case ast.SEND:
-			p.print(token.CHAN, blank, token.ARROW);
+			p.print(token.CHAN, token.ARROW);
 		}
 		p.print(blank);
 		p.expr(x.Value);
@@ -784,15 +819,14 @@ func (p *printer) stmtList(list []ast.Stmt) {
 		optSemi := false;
 		for i, s := range list {
 			if i > 0 {
-				if !optSemi || p.optSemis() {
-					// semicolon is required
+				if !optSemi {
 					p.print(token.SEMICOLON);
 				}
 				p.print(newline);
 			}
 			optSemi = p.stmt(s);
 		}
-		if p.optSemis() {
+		if !optSemi {
 			p.print(token.SEMICOLON);
 		}
 		p.print(-1);
@@ -889,9 +923,9 @@ func (p *printer) stmt(stmt ast.Stmt) (optSemi bool) {
 		p.print(s.Tok);
 
 	case *ast.AssignStmt:
-		p.exprList(s.Lhs);
-		p.print(blank, s.TokPos, s.Tok, blank);
-		p.exprList(s.Rhs);
+		p.exprList(s.Lhs, commaSep);
+		p.print(blank, s.TokPos, s.Tok);
+		p.exprList(s.Rhs, blankStart | commaSep);
 
 	case *ast.GoStmt:
 		p.print(token.GO, blank);
@@ -904,8 +938,7 @@ func (p *printer) stmt(stmt ast.Stmt) (optSemi bool) {
 	case *ast.ReturnStmt:
 		p.print(token.RETURN);
 		if s.Results != nil {
-			p.print(blank);
-			p.exprList(s.Results);
+			p.exprList(s.Results, blankStart | commaSep);
 		}
 
 	case *ast.BranchStmt:
@@ -932,8 +965,8 @@ func (p *printer) stmt(stmt ast.Stmt) (optSemi bool) {
 
 	case *ast.CaseClause:
 		if s.Values != nil {
-			p.print(token.CASE, blank);
-			p.exprList(s.Values);
+			p.print(token.CASE);
+			p.exprList(s.Values, blankStart | commaSep);
 		} else {
 			p.print(token.DEFAULT);
 		}
@@ -949,8 +982,8 @@ func (p *printer) stmt(stmt ast.Stmt) (optSemi bool) {
 
 	case *ast.TypeCaseClause:
 		if s.Types != nil {
-			p.print(token.CASE, blank);
-			p.exprList(s.Types);
+			p.print(token.CASE);
+			p.exprList(s.Types, blankStart | commaSep);
 		} else {
 			p.print(token.DEFAULT);
 		}
@@ -1041,8 +1074,8 @@ func (p *printer) spec(spec ast.Spec) (comment *ast.CommentGroup, optSemi bool)
 			optSemi = p.expr(s.Type);
 		}
 		if s.Values != nil {
-			p.print(tab, token.ASSIGN, blank);
-			p.exprList(s.Values);
+			p.print(tab, token.ASSIGN);
+			p.exprList(s.Values, blankStart | commaSep);
 			optSemi = false;
 		}
 		comment = s.Comment;
@@ -1076,18 +1109,7 @@ func (p *printer) decl(decl ast.Decl) (comment *ast.CommentGroup, optSemi bool)
 			// group of parenthesized declarations
 			p.print(d.Lparen, token.LPAREN);
 			if len(d.Specs) > 0 {
-				p.print(+1, newline);
-				if p.mode & Reverse != 0 && p.level == 0 {
-					for i := len(d.Specs)-1; i >= 0; i-- {
-						s := d.Specs[i];
-						if i < len(d.Specs)-1 {
-							p.print(token.SEMICOLON);
-							p.lineComment(comment);
-							p.print(newline);
-						}
-						comment, optSemi = p.spec(s);
-					}
-				} else {
+				p.print(+1, formfeed);
 				for i, s := range d.Specs {
 					if i > 0 {
 						p.print(token.SEMICOLON);
@@ -1096,12 +1118,9 @@ func (p *printer) decl(decl ast.Decl) (comment *ast.CommentGroup, optSemi bool)
 					}
 					comment, optSemi = p.spec(s);
 				}
-				}
-				if p.optSemis() {
 				p.print(token.SEMICOLON);
-				}
 				p.lineComment(comment);
-				p.print(-1, newline);
+				p.print(-1, formfeed);
 			}
 			p.print(d.Rparen, token.RPAREN);
 			comment = nil;  // comment was already printed
@@ -1113,10 +1132,6 @@ func (p *printer) decl(decl ast.Decl) (comment *ast.CommentGroup, optSemi bool)
 		}
 
 	case *ast.FuncDecl:
-		if d.Body == nil && p.mode & Reverse != 0 {
-			// omit forward declarations in reverse mode
-			break;
-		}
 		p.leadComment(d.Doc);
 		p.print(lineTag(d.Pos()), token.FUNC, blank);
 		if recv := d.Recv; recv != nil {
@@ -1154,26 +1169,11 @@ func (p *printer) file(src *ast.File) {
 	p.print(src.Pos(), token.PACKAGE, blank);
 	p.expr(src.Name);
 
-	if p.mode & Reverse != 0 {
-		for i := len(src.Decls)-1; i >= 0; i-- {
-			d := src.Decls[i];
-			p.print(newline, newline);
-			comment, _ := p.decl(d);
-			if p.optSemis() {
-				p.print(token.SEMICOLON);
-			}
-			p.lineComment(comment);
-		}
-	} else {
 	for _, d := range src.Decls {
 		p.print(newline, newline);
 		comment, _ := p.decl(d);
-			if p.optSemis() {
-				p.print(token.SEMICOLON);
-			}
 		p.lineComment(comment);
 	}
-	}
 
 	p.print(newline);
 }
@@ -1216,10 +1216,7 @@ func Fprint(output io.Writer, node interface{}, mode uint, tabwidth int) (int, o
 			comment, _ := p.decl(n);
 			p.lineComment(comment);  // no newline at end
 		case *ast.File:
-			if mode & Reverse == 0 {
-				// don't print comments in reverse mode
 			p.comment = n.Comments;
-			}
 			p.file(n);
 		default:
 			p.errors <- os.NewError("unsupported node type");

src/pkg/go/printer/printer_test.go

@@ -101,6 +101,7 @@ type entry struct {
 var data = []entry{
 	entry{ "source1.go", "golden1.go", false },
 	entry{ "source1.go", "golden1.x", true },
+	entry{ "linebreaks.go", "linebreaks.golden", false },
 }
 
 

src/pkg/go/printer/testdata/golden1.go

@@ -11,13 +11,13 @@ import 	"fmt"	// fmt
 const c0	= 0	// zero
 const (
 	c1	= iota;	// c1
-	c2	// c2
+	c2;	// c2
 )
 
 
 // The T type.
 type T struct {
-	a, b, c	int	// 3 fields
+	a, b, c	int;	// 3 fields
 }
 
 // This comment group should be separated
@@ -33,11 +33,11 @@ var ()
 // This comment SHOULD be associated with the next declaration.
 func f0() {
 	const pi		= 3.14;					// pi
-	var s1 struct {}	/* an empty struct */	/* foo */
+	var s1 struct{}	/* an empty struct */	/* foo */
 	// a struct constructor
 	// --------------------
-	var s2 struct {}	= struct {}{};
-	x := pi
+	var s2 struct{}	= struct{}{};
+	x := pi;
 }
 //
 // NO SPACE HERE
@@ -48,17 +48,17 @@ func f1() {
 	// 2
 	/* 3 */
 	/* 4 */
-	f0()
+	f0();
 }
 
 func abs(x int) int {
 	if x < 0 {	// the tab printed before this comment's // must not affect the remaining lines
-		return -x	// this statement should be properly indented
+		return -x;	// this statement should be properly indented
 	}
-	return x
+	return x;
 }
 
-func typeswitch(x interface {}) {
+func typeswitch(x interface{}) {
 	switch v := x.(type) {
 	case bool, int, float:
 	case string:

src/pkg/go/printer/testdata/linebreaks.go

+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package linebreaks
+
+import (
+	"bytes";
+	"fmt";
+	"io";
+	"os";
+	"reflect";
+	"strings";
+	"testing";
+)
+
+type untarTest struct {
+	file string;
+	headers []*Header;
+}
+
+var untarTests = []*untarTest{
+	&untarTest{
+		file: "testdata/gnu.tar",
+		headers: []*Header{
+			&Header{
+				Name: "small.txt",
+				Mode: 0640,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 5,
+				Mtime: 1244428340,
+				Typeflag: '0',
+				Uname: "dsymonds",
+				Gname: "eng",
+			},
+			&Header{
+				Name: "small2.txt",
+				Mode: 0640,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 11,
+				Mtime: 1244436044,
+				Typeflag: '0',
+				Uname: "dsymonds",
+				Gname: "eng",
+			},
+		},
+	},
+	&untarTest{
+		file: "testdata/star.tar",
+		headers: []*Header{
+			&Header{
+				Name: "small.txt",
+				Mode: 0640,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 5,
+				Mtime: 1244592783,
+				Typeflag: '0',
+				Uname: "dsymonds",
+				Gname: "eng",
+				Atime: 1244592783,
+				Ctime: 1244592783,
+			},
+			&Header{
+				Name: "small2.txt",
+				Mode: 0640,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 11,
+				Mtime: 1244592783,
+				Typeflag: '0',
+				Uname: "dsymonds",
+				Gname: "eng",
+				Atime: 1244592783,
+				Ctime: 1244592783,
+			},
+		},
+	},
+	&untarTest{
+		file: "testdata/v7.tar",
+		headers: []*Header{
+			&Header{
+				Name: "small.txt",
+				Mode: 0444,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 5,
+				Mtime: 1244593104,
+				Typeflag: '\x00',
+			},
+			&Header{
+				Name: "small2.txt",
+				Mode: 0444,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 11,
+				Mtime: 1244593104,
+				Typeflag: '\x00',
+			},
+		},
+	},
+}
+
+var facts = map[int] string {
+	0: "1",
+	1: "1",
+	2: "2",
+	10: "3628800",
+	20: "2432902008176640000",
+	100: "933262154439441526816992388562667004907159682643816214685929"
+		"638952175999932299156089414639761565182862536979208272237582"
+		"51185210916864000000000000000000000000",
+}
+
+func TestReader(t *testing.T) {
+testLoop:
+	for i, test := range untarTests {
+		f, err := os.Open(test.file, os.O_RDONLY, 0444);
+		if err != nil {
+			t.Errorf("test %d: Unexpected error: %v", i, err);
+			continue
+		}
+		tr := NewReader(f);
+		for j, header := range test.headers {
+			hdr, err := tr.Next();
+			if err != nil || hdr == nil {
+				t.Errorf("test %d, entry %d: Didn't get entry: %v", i, j, err);
+				f.Close();
+				continue testLoop
+			}
+			if !reflect.DeepEqual(hdr, header) {
+				t.Errorf("test %d, entry %d: Incorrect header:\nhave %+v\nwant %+v",
+					 i, j, *hdr, *header);
+			}
+		}
+		hdr, err := tr.Next();
+		if hdr != nil || err != nil {
+			t.Errorf("test %d: Unexpected entry or error: hdr=%v err=%v", i, err);
+		}
+		f.Close();
+	}
+}

src/pkg/go/printer/testdata/linebreaks.golden

+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package linebreaks
+
+import (
+		"bytes";
+		"fmt";
+		"io";
+		"os";
+		"reflect";
+		"strings";
+		"testing";
+)
+
+type untarTest struct {
+	file	string;
+	headers	[]*Header;
+}
+
+var untarTests	= []*untarTest{
+	&untarTest{
+		file: "testdata/gnu.tar",
+		headers: []*Header{
+			&Header{
+				Name: "small.txt",
+				Mode: 0640,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 5,
+				Mtime: 1244428340,
+				Typeflag: '0',
+				Uname: "dsymonds",
+				Gname: "eng",
+			},
+			&Header{
+				Name: "small2.txt",
+				Mode: 0640,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 11,
+				Mtime: 1244436044,
+				Typeflag: '0',
+				Uname: "dsymonds",
+				Gname: "eng",
+			},
+		},
+	},
+	&untarTest{
+		file: "testdata/star.tar",
+		headers: []*Header{
+			&Header{
+				Name: "small.txt",
+				Mode: 0640,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 5,
+				Mtime: 1244592783,
+				Typeflag: '0',
+				Uname: "dsymonds",
+				Gname: "eng",
+				Atime: 1244592783,
+				Ctime: 1244592783,
+			},
+			&Header{
+				Name: "small2.txt",
+				Mode: 0640,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 11,
+				Mtime: 1244592783,
+				Typeflag: '0',
+				Uname: "dsymonds",
+				Gname: "eng",
+				Atime: 1244592783,
+				Ctime: 1244592783,
+			},
+		},
+	},
+	&untarTest{
+		file: "testdata/v7.tar",
+		headers: []*Header{
+			&Header{
+				Name: "small.txt",
+				Mode: 0444,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 5,
+				Mtime: 1244593104,
+				Typeflag: '\x00',
+			},
+			&Header{
+				Name: "small2.txt",
+				Mode: 0444,
+				Uid: 73025,
+				Gid: 5000,
+				Size: 11,
+				Mtime: 1244593104,
+				Typeflag: '\x00',
+			},
+		},
+	},
+}
+
+var facts	= map[int]string{
+	0: "1",
+	1: "1",
+	2: "2",
+	10: "3628800",
+	20: "2432902008176640000",
+	100:
+		"933262154439441526816992388562667004907159682643816214685929"
+		"638952175999932299156089414639761565182862536979208272237582"
+		"51185210916864000000000000000000000000"
+	,
+}
+
+func TestReader(t *testing.T) {
+
+testLoop:	for i, test := range untarTests {
+		f, err := os.Open(test.file, os.O_RDONLY, 0444);
+		if err != nil {
+			t.Errorf("test %d: Unexpected error: %v", i, err);
+			continue;
+		}
+		tr := NewReader(f);
+		for j, header := range test.headers {
+			hdr, err := tr.Next();
+			if err != nil || hdr == nil {
+				t.Errorf("test %d, entry %d: Didn't get entry: %v", i, j, err);
+				f.Close();
+				continue testLoop;
+			}
+			if !reflect.DeepEqual(hdr, header) {
+				t.Errorf(
+					"test %d, entry %d: Incorrect header:\nhave %+v\nwant %+v",
+					i, j, *hdr, *header
+				);
+			}
+		}
+		hdr, err := tr.Next();
+		if hdr != nil || err != nil {
+			t.Errorf("test %d: Unexpected entry or error: hdr=%v err=%v", i, err);
+		}
+		f.Close();
+	}
+}