From: Ian Lance Taylor <iant@golang.org>
Date: Fri, 26 Jun 2020 18:29:34 +0000 (+0000)
Subject: Revert "encoding/xml: fix reserved namespace check to be case-insensitive"
X-Git-Tag: go1.15rc1~47
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=2ca0f5a1e2e637cd15b50f3c625cbb8d169575ab;p=gostls13.git

Revert "encoding/xml: fix reserved namespace check to be case-insensitive"

This reverts CL 203417.

Reason for revert: This change changes uses of tags like "XMLSchema-instance" without any recourse.

For #35151
Fixes #39876

Change-Id: I4c85c8267a46b3748664b5078794dafffb42aa26
Reviewed-on: https://go-review.googlesource.com/c/go/+/240179
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Andrew Bonventre <andybons@golang.org>
---

diff --git a/src/encoding/xml/marshal.go b/src/encoding/xml/marshal.go
index d8a04a95a2..0554b0d204 100644
--- a/src/encoding/xml/marshal.go
+++ b/src/encoding/xml/marshal.go
@@ -345,11 +345,8 @@ func (p *printer) createAttrPrefix(url string) string {
 	if prefix == "" || !isName([]byte(prefix)) || strings.Contains(prefix, ":") {
 		prefix = "_"
 	}
-	// xmlanything is reserved and any variant of it regardless of
-	// case should be matched, so:
-	//    (('X'|'x') ('M'|'m') ('L'|'l'))
-	// See Section 2.3 of https://www.w3.org/TR/REC-xml/
-	if len(prefix) >= 3 && strings.EqualFold(prefix[:3], "xml") {
+	if strings.HasPrefix(prefix, "xml") {
+		// xmlanything is reserved.
 		prefix = "_" + prefix
 	}
 	if p.attrNS[prefix] != "" {
diff --git a/src/encoding/xml/marshal_test.go b/src/encoding/xml/marshal_test.go
index d2e5137afd..31309ef2ca 100644
--- a/src/encoding/xml/marshal_test.go
+++ b/src/encoding/xml/marshal_test.go
@@ -2283,30 +2283,6 @@ var encodeTokenTests = []struct {
 		}},
 	},
 	want: `<foo xmlns="space"><bar xmlns="space" xmlns:space="space" space:attr="value">`,
-}, {
-	desc: "reserved namespace prefix -- all lower case",
-	toks: []Token{
-		StartElement{Name{"", "foo"}, []Attr{
-			{Name{"http://www.w3.org/2001/xmlSchema-instance", "nil"}, "true"},
-		}},
-	},
-	want: `<foo xmlns:_xmlSchema-instance="http://www.w3.org/2001/xmlSchema-instance" _xmlSchema-instance:nil="true">`,
-}, {
-	desc: "reserved namespace prefix -- all upper case",
-	toks: []Token{
-		StartElement{Name{"", "foo"}, []Attr{
-			{Name{"http://www.w3.org/2001/XMLSchema-instance", "nil"}, "true"},
-		}},
-	},
-	want: `<foo xmlns:_XMLSchema-instance="http://www.w3.org/2001/XMLSchema-instance" _XMLSchema-instance:nil="true">`,
-}, {
-	desc: "reserved namespace prefix -- all mixed case",
-	toks: []Token{
-		StartElement{Name{"", "foo"}, []Attr{
-			{Name{"http://www.w3.org/2001/XmLSchema-instance", "nil"}, "true"},
-		}},
-	},
-	want: `<foo xmlns:_XmLSchema-instance="http://www.w3.org/2001/XmLSchema-instance" _XmLSchema-instance:nil="true">`,
 }}
 
 func TestEncodeToken(t *testing.T) {