Skip to content

Escape whitespace characters that XML parsers normalize #140

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
zhengchun merged 1 commit into from
Oct 14, 2026
Merged

Escape whitespace characters that XML parsers normalize #140

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 16 additions & 3 deletions node.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,6 @@ import (
"bufio"
"encoding/xml"
"fmt"
"html"
"io"
"strings"
)
Expand Down Expand Up @@ -245,11 +244,25 @@ func (i *indentation) writeIndent() (err error) {
return
}

// textEscaper escapes text like html.EscapeString, and also escapes carriage
// returns, which an XML parser would otherwise read back as newlines.
var textEscaper = strings.NewReplacer(
`&`, "&amp;", `'`, "&#39;", `<`, "&lt;", `>`, "&gt;", `"`, "&#34;",
"\r", "&#13;",
)

// attrEscaper escapes attribute values like textEscaper, and also escapes
// tabs and newlines, which an XML parser would otherwise read back as spaces.
var attrEscaper = strings.NewReplacer(
`&`, "&amp;", `'`, "&#39;", `<`, "&lt;", `>`, "&gt;", `"`, "&#34;",
"\t", "&#9;", "\n", "&#10;", "\r", "&#13;",
)

func outputXML(w io.Writer, n *Node, preserveSpaces bool, config *outputConfiguration, indent *indentation) (err error) {
preserveSpaces = calculatePreserveSpaces(n, preserveSpaces)
switch n.Type {
case TextNode:
_, err = io.WriteString(w, html.EscapeString(n.sanitizedData(preserveSpaces)))
_, err = io.WriteString(w, textEscaper.Replace(n.sanitizedData(preserveSpaces)))
return
case CharDataNode:
_, err = fmt.Fprintf(w, "<![CDATA[%v]]>", n.Data)
Expand Down Expand Up @@ -301,7 +314,7 @@ func outputXML(w io.Writer, n *Node, preserveSpaces bool, config *outputConfigur
return
}

_, err = fmt.Fprintf(w, `"%v"`, html.EscapeString(attr.Value))
_, err = fmt.Fprintf(w, `"%v"`, attrEscaper.Replace(attr.Value))
if err != nil {
return
}
Expand Down
24 changes: 24 additions & 0 deletions node_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -848,3 +848,27 @@ func TestProcessingInstruction(t *testing.T) {
t.Errorf("Output mismatch:\nExpected: %s\nGot: %s", expected, output)
}
}

func TestOutputXMLKeepsWhitespaceCharacters(t *testing.T) {
s := `<a x="tab&#9;nl&#10;cr&#13;end" xml:space="preserve">one&#13;two</a>`
doc, err := Parse(strings.NewReader(s))
if err != nil {
t.Fatal(err)
}
a := FindOne(doc, "//a")
if got, want := a.SelectAttr("x"), "tab\tnl\ncr\rend"; got != want {
t.Fatalf("attribute: got %q, want %q", got, want)
}

reparsed, err := Parse(strings.NewReader(doc.OutputXML(true)))
if err != nil {
t.Fatal(err)
}
b := FindOne(reparsed, "//a")
if got, want := b.SelectAttr("x"), a.SelectAttr("x"); got != want {
t.Errorf("attribute after round trip: got %q, want %q", got, want)
}
if got, want := b.InnerText(), a.InnerText(); got != want {
t.Errorf("text after round trip: got %q, want %q", got, want)
}
}