From 483f3dc39fb187dadd28a0d06a92084a207715b3 Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <iant@golang.org>
Date: Tue, 29 Nov 2022 19:37:10 +0000
Subject: [PATCH] Revert "encoding/xml: disallow empty namespace when prefix is
 set"

This reverts CL 105636.

Reason for revert: Fails with existing XML data.  At this stage in the release cycle we should revert, and try again next time with some way to support existing XML.

For #8068

Change-Id: Ia84cbf3a84878ac7190f72998545dee22c36c45e
Reviewed-on: https://go-review.googlesource.com/c/go/+/453996
Auto-Submit: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
---
 src/encoding/xml/xml.go      |  4 ----
 src/encoding/xml/xml_test.go | 29 -----------------------------
 2 files changed, 33 deletions(-)

diff --git a/src/encoding/xml/xml.go b/src/encoding/xml/xml.go
index 9df556a136..1f3084e5ca 100644
--- a/src/encoding/xml/xml.go
+++ b/src/encoding/xml/xml.go
@@ -302,10 +302,6 @@ func (d *Decoder) Token() (Token, error) {
 		// the translations first.
 		for _, a := range t1.Attr {
 			if a.Name.Space == xmlnsPrefix {
-				if a.Value == "" {
-					d.err = d.syntaxError("empty namespace with prefix")
-					return nil, d.err
-				}
 				v, ok := d.ns[a.Name.Local]
 				d.pushNs(a.Name.Local, v, ok)
 				d.ns[a.Name.Local] = a.Value
diff --git a/src/encoding/xml/xml_test.go b/src/encoding/xml/xml_test.go
index df25812521..30fb94da6d 100644
--- a/src/encoding/xml/xml_test.go
+++ b/src/encoding/xml/xml_test.go
@@ -916,35 +916,6 @@ func TestIssue5880(t *testing.T) {
 	}
 }
 
-func TestIssue8068(t *testing.T) {
-	emptyError := SyntaxError{}
-	noError := emptyError.Error()
-	testCases := []struct {
-		s       string
-		wantErr SyntaxError
-	}{
-		{`<foo xmlns:bar="a"></foo>`, SyntaxError{}},
-		{`<foo xmlns:bar=""></foo>`, SyntaxError{Msg: "empty namespace with prefix", Line: 1}},
-		{`<foo xmlns:="a"></foo>`, SyntaxError{}},
-		{`<foo xmlns:""></foo>`, SyntaxError{Msg: "attribute name without = in element", Line: 1}},
-		{`<foo xmlns:"a"></foo>`, SyntaxError{Msg: "attribute name without = in element", Line: 1}},
-	}
-	var dest string
-	for _, tc := range testCases {
-		if got, want := Unmarshal([]byte(tc.s), &dest), tc.wantErr.Error(); got == nil {
-			if want != noError {
-				t.Errorf("%q: got nil, want %s", tc.s, want)
-			}
-		} else {
-			if want == "" {
-				t.Errorf("%q: got %s, want nil", tc.s, got)
-			} else if got.Error() != want {
-				t.Errorf("%q: got %s, want %s", tc.s, got, want)
-			}
-		}
-	}
-}
-
 func TestIssue8535(t *testing.T) {
 
 	type ExampleConflict struct {
-- 
2.48.1