Bug 1535765 [wpt PR 15779] - XMLSerializer: Keep redundant but harmle…

…ss default namespace declarations, a=testonly

Automatic update from web-platform-tests
XMLSerializer: Keep redundant but harmless default namespace declarations

Since crrev.com/632142, XMLSerializer has dropped redundant xmlns="..."
declarations. It matches to IE, Edge, and DOM P&S standard.  This CL
reverts the behavior to unbreak existing applications.  The restored
behavior matches to Firefox and Safari.

* MarkupAccumulator::AppendElement():
  Even if ignore_namespace_definition_attribute_ is set, we drop a
  xmlns="..." only if its value is inconsistent with element's
  namespace.

* MarkupAccumulator::AppendStartTagOpen():
  if local_default_namespace is "" and ns is null, do not emit xmlns="".
  This avoids to serialize xmlns="" twice.

Bug: w3c/DOM-Parsing#47
Bug: 940204
Change-Id: I2978ddc9a3f9511d227a9a1b902f1811ac1c3c07
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1516124
Reviewed-by: Yoshifumi Inoue <yosinchromium.org>
Commit-Queue: Kent Tamura <tkentchromium.org>
Auto-Submit: Kent Tamura <tkentchromium.org>
Cr-Commit-Position: refs/heads/master{#639873}

--

wpt-commits: 4dc79803ad127fb635a03ec8b248c8671b4c3b67
wpt-pr: 15779

UltraBlame original commit: 41a76d86404be10336a61e3a8fbd86ac0aca467f

testing/web-platform/tests/domparsing/XMLSerializer-serializeToString.html

@@ -503,6 +503,165 @@
 (
 )
 {
+assert_equals
+(
+serialize
+(
+parse
+(
+'
+<
+root
+>
+<
+child
+xmlns
+=
+"
+"
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+>
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+'
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+'
+<
+root
+>
+<
+child
+/
+>
+<
+/
+root
+>
+'
+)
+;
+assert_equals
+(
+serialize
+(
+parse
+(
+'
+<
+root
+xmlns
+=
+"
+"
+>
+<
+child
+xmlns
+=
+"
+"
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+>
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+'
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+'
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+root
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+<
+child
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+>
+<
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+root
+>
+'
+)
+;
+assert_equals
+(
+serialize
+(
+parse
+(
+'
+<
+root
+xmlns
+=
+"
+u1
+"
+>
+<
+child
+xmlns
+=
+"
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+"
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+'
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+'
+<
+root
+xmlns
+=
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+>
+<
+child
+/
+>
+<
+/
+root
+>
+'
+)
+;
+}
+'
+Check
+if
+redundant
+xmlns
+=
+"
+.
+.
+.
+"
+is
+dropped
+.
+'
+)
+;
+test
+(
+function
+(
+)
+{
 const
 root
 =
@@ -2099,97 +2258,6 @@
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