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Commit dec5bb78 authored by Arvindh Rajesh Tamilmani's avatar Arvindh Rajesh Tamilmani Committed by Russ Cox
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xml: handle unexpected EOF while parsing and fix a bug in name 

mustgetc reports unexpected EOF as SyntaxError.  using
mustgetc seems to be a better approach than letting the
caller handle unexpected EOF every time.

name: the second if statement should explicitly return
ok==false.

R=rsc
https://golang.org/cl/174083
parent 19c18358
Show whitespace changes
Inline Side-by-side
Showing with 104 additions and 27 deletions
src/pkg/xml/xml.go
View file @ dec5bb78
......@@ -409,7 +409,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
return CharData(data), nil;
}
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
switch b {
......@@ -423,7 +423,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
return nil, p.err;
}
p.space();
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
if b != '>' {
......@@ -438,17 +438,17 @@ func (p *Parser) RawToken() (Token, os.Error) {
// the version is 1.0 and the encoding is UTF-8.
var target string;
if target, ok = p.name(); !ok {
return nil, p.err
if p.err == nil {
p.err = SyntaxError("expected target name after <?")
}
return nil, p.err;
}
p.space();
p.buf.Reset();
var b0 byte;
for {
if b, ok = p.getc(); !ok {
if p.err == os.EOF {
p.err = SyntaxError("unterminated <? directive")
}
return nil, p.err;
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
p.buf.WriteByte(b);
if b0 == '?' && b == '>' {
......@@ -462,13 +462,13 @@ func (p *Parser) RawToken() (Token, os.Error) {
case '!':
// <!: Maybe comment, maybe CDATA.
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
switch b {
case '-': // <!-
// Probably <!-- for a comment.
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
if b != '-' {
......@@ -479,11 +479,8 @@ func (p *Parser) RawToken() (Token, os.Error) {
p.buf.Reset();
var b0, b1 byte;
for {
if b, ok = p.getc(); !ok {
if p.err == os.EOF {
p.err = SyntaxError("unterminated <!-- comment")
}
return nil, p.err;
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
p.buf.WriteByte(b);
if b0 == '-' && b1 == '-' && b == '>' {
......@@ -498,7 +495,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
case '[': // <![
// Probably <![CDATA[.
for i := 0; i < 6; i++ {
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
if b != "CDATA["[i] {
......@@ -519,7 +516,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
p.buf.Reset();
p.buf.WriteByte(b);
for {
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
if b == '>' {
......@@ -548,12 +545,12 @@ func (p *Parser) RawToken() (Token, os.Error) {
attr = make([]Attr, 0, 4);
for {
p.space();
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
if b == '/' {
empty = true;
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
if b != '>' {
......@@ -584,7 +581,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
return nil, p.err;
}
p.space();
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
if b != '=' {
......@@ -592,7 +589,7 @@ func (p *Parser) RawToken() (Token, os.Error) {
return nil, p.err;
}
p.space();
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return nil, p.err
}
if b != '"' && b != '\'' {
......@@ -652,6 +649,19 @@ func (p *Parser) getc() (b byte, ok bool) {
return b, true;
}
// Must read a single byte.
// If there is no byte to read,
// set p.err to SyntaxError("unexpected EOF")
// and return ok==false
func (p *Parser) mustgetc() (b byte, ok bool) {
if b, ok = p.getc(); !ok {
if p.err == os.EOF {
p.err = SyntaxError("unexpected EOF")
}
}
return;
}
// Unread a single byte.
func (p *Parser) ungetc(b byte) {
if b == '\n' {
......@@ -678,7 +688,7 @@ func (p *Parser) text(quote int, cdata bool) []byte {
p.buf.Reset();
Input:
for {
b, ok := p.getc();
b, ok := p.mustgetc();
if !ok {
return nil
}
......@@ -717,7 +727,10 @@ Input:
for i = 0; i < len(p.tmp); i++ {
p.tmp[i], p.err = p.r.ReadByte();
if p.err != nil {
return nil
if p.err == os.EOF {
p.err = SyntaxError("unexpected EOF")
}
return nil;
}
c := p.tmp[i];
if c == ';' {
......@@ -819,22 +832,23 @@ func (p *Parser) nsname() (name Name, ok bool) {
}
// Get name: /first(first|second)*/
// Do not set p.err if the name is missing: let the caller provide better context.
// Do not set p.err if the name is missing (unless unexpected EOF is received):
// let the caller provide better context.
func (p *Parser) name() (s string, ok bool) {
var b byte;
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return
}
// As a first approximation, we gather the bytes [A-Za-z_:.-\x80-\xFF]*
if b < utf8.RuneSelf && !isNameByte(b) {
p.ungetc(b);
return;
return "", false;
}
p.buf.Reset();
p.buf.WriteByte(b);
for {
if b, ok = p.getc(); !ok {
if b, ok = p.mustgetc(); !ok {
return
}
if b < utf8.RuneSelf && !isNameByte(b) {
......
src/pkg/xml/xml_test.go
View file @ dec5bb78
......@@ -94,6 +94,57 @@ var cookedTokens = []Token{
Comment(strings.Bytes(" missing final newline ")),
}
var xmlInput = []string{
// unexpected EOF cases
"<",
"<t",
"<t ",
"<t/",
"<t/>c",
"<!",
"<!-",
"<!--",
"<!--c-",
"<!--c--",
"<!d",
"<t></",
"<t></t",
"<?",
"<?p",
"<t a",
"<t a=",
"<t a='",
"<t a=''",
"<t/><![",
"<t/><![C",
"<t/><![CDATA[d",
"<t/><![CDATA[d]",
"<t/><![CDATA[d]]",
// other Syntax errors
" ",
">",
"<>",
"<t/a",
"<0 />",
"<?0 >",
// "<!0 >", // let the Token() caller handle
"</0>",
"<t 0=''>",
"<t a='&'>",
"<t a='<'>",
"<t>&nbspc;</t>",
"<t a>",
"<t a=>",
"<t a=v>",
// "<![CDATA[d]]>", // let the Token() caller handle
"cdata",
"<t></e>",
"<t></>",
"<t></t!",
"<t>cdata]]></t>",
}
type stringReader struct {
s string;
off int;
......@@ -149,3 +200,15 @@ func TestToken(t *testing.T) {
}
}
}
func TestSyntax(t *testing.T) {
for i := range xmlInput {
p := NewParser(StringReader(xmlInput[i]));
var err os.Error;
for _, err = p.Token(); err == nil; _, err = p.Token() {
}
if _, ok := err.(SyntaxError); !ok {
t.Fatalf(`xmlInput "%s": expected SyntaxError not received`, xmlInput[i])
}
}
}
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