pkg: Removing duplicated words ("of of", etc.), mostly from comments.

Ran 'double.pl' on the pkg tree to identify doubled words.
One change to an error string return in x509;  the rest are in comments.
Thanks to Matt Jibson for the idea.

R=golang-dev, bsiegert
CC=golang-dev
https://golang.org/cl/6344089

src/pkg/crypto/x509/verify.go

@@ -42,7 +42,7 @@ type CertificateInvalidError struct {
 func (e CertificateInvalidError) Error() string {
 	switch e.Reason {
 	case NotAuthorizedToSign:
-		return "x509: certificate is not authorized to sign other other certificates"
+		return "x509: certificate is not authorized to sign other certificates"
 	case Expired:
 		return "x509: certificate has expired or is not yet valid"
 	case CANotAuthorizedForThisName:

src/pkg/database/sql/fakedb_test.go

@@ -31,7 +31,7 @@ var _ = log.Printf
 //   INSERT|<tablename>|col=val,col2=val2,col3=?
 //   SELECT|<tablename>|projectcol1,projectcol2|filtercol=?,filtercol2=?
 //
-// When opening a a fakeDriver's database, it starts empty with no
+// When opening a fakeDriver's database, it starts empty with no
 // tables.  All tables and data are stored in memory only.
 type fakeDriver struct {
 	mu        sync.Mutex
@@ -234,7 +234,7 @@ func checkSubsetTypes(args []driver.Value) error {
 
 func (c *fakeConn) Exec(query string, args []driver.Value) (driver.Result, error) {
 	// This is an optional interface, but it's implemented here
-	// just to check that all the args of of the proper types.
+	// just to check that all the args are of the proper types.
 	// ErrSkip is returned so the caller acts as if we didn't
 	// implement this at all.
 	err := checkSubsetTypes(args)
@@ -249,7 +249,7 @@ func errf(msg string, args ...interface{}) error {
 }
 
 // parts are table|selectCol1,selectCol2|whereCol=?,whereCol2=?
-// (note that where where columns must always contain ? marks,
+// (note that where columns must always contain ? marks,
 //  just a limitation for fakedb)
 func (c *fakeConn) prepareSelect(stmt *fakeStmt, parts []string) (driver.Stmt, error) {
 	if len(parts) != 3 {

src/pkg/go/doc/reader.go

@@ -494,7 +494,7 @@ func (r *reader) readPackage(pkg *ast.Package, mode Mode) {
 	r.funcs = make(methodSet)
 
 	// sort package files before reading them so that the
-	// result result does not depend on map iteration order
+	// result does not depend on map iteration order
 	i := 0
 	for filename := range pkg.Files {
 		r.filenames[i] = filename

src/pkg/html/template/url.go

@@ -60,7 +60,7 @@ func urlProcessor(norm bool, args ...interface{}) string {
 		c := s[i]
 		switch c {
 		// Single quote and parens are sub-delims in RFC 3986, but we
-		// escape them so the output can be embedded in in single
+		// escape them so the output can be embedded in single
 		// quoted attributes and unquoted CSS url(...) constructs.
 		// Single quotes are reserved in URLs, but are only used in
 		// the obsolete "mark" rule in an appendix in RFC 3986

src/pkg/mime/grammar.go

@@ -22,7 +22,7 @@ func isTokenChar(r rune) bool {
 	return r > 0x20 && r < 0x7f && !isTSpecial(r)
 }
 
-// isToken returns true if s is a 'token' as as defined by RFC 1521
+// isToken returns true if s is a 'token' as defined by RFC 1521
 // and RFC 2045.
 func isToken(s string) bool {
 	if s == "" {

src/pkg/os/exec/exec.go

@@ -16,7 +16,7 @@ import (
 	"syscall"
 )
 
-// Error records the name of a binary that failed to be be executed
+// Error records the name of a binary that failed to be executed
 // and the reason it failed.
 type Error struct {
 	Name string

src/pkg/regexp/regexp.go

@@ -441,7 +441,7 @@ func (re *Regexp) ReplaceAllLiteralString(src, repl string) string {
 }
 
 // ReplaceAllStringFunc returns a copy of src in which all matches of the
-// Regexp have been replaced by the return value of of function repl applied
+// Regexp have been replaced by the return value of function repl applied
 // to the matched substring.  The replacement returned by repl is substituted
 // directly, without using Expand.
 func (re *Regexp) ReplaceAllStringFunc(src string, repl func(string) string) string {
@@ -539,7 +539,7 @@ func (re *Regexp) ReplaceAllLiteral(src, repl []byte) []byte {
 }
 
 // ReplaceAllFunc returns a copy of src in which all matches of the
-// Regexp have been replaced by the return value of of function repl applied
+// Regexp have been replaced by the return value of function repl applied
 // to the matched byte slice.  The replacement returned by repl is substituted
 // directly, without using Expand.
 func (re *Regexp) ReplaceAllFunc(src []byte, repl func([]byte) []byte) []byte {

src/pkg/unsafe/unsafe.go

@@ -32,6 +32,6 @@ func Sizeof(v ArbitraryType) uintptr
 func Offsetof(v ArbitraryType) uintptr
 
 // Alignof returns the alignment of the value v.  It is the maximum value m such
-// that the address of a variable with the type of v will always always be zero mod m.
+// that the address of a variable with the type of v will always be zero mod m.
 // If v is of the form structValue.field, it returns the alignment of field f within struct object obj.
 func Alignof(v ArbitraryType) uintptr