Bug 1838450 - Refine attribute handling. r=emilio

whatwg/dom#1176
https://dom.spec.whatwg.org/#concept-element-attributes-change-ext
"attribute change steps"  at https://html.spec.whatwg.org/multipage/popover.html#attr-popover

Differential Revision: https://phabricator.services.mozilla.com/D181880

UltraBlame original commit: 00b027478170756439b780282f9cfdf15edea985

dom/html/nsGenericHTMLElement.cpp

@@ -3393,38 +3393,29 @@ AfterSetPopoverAttr
 (
 )
 {
-const
-nsAttrValue
-*
-newValue
-=
-GetParsedAttr
-(
-nsGkAtoms
-:
-:
-popover
-)
-;
-const
-PopoverAttributeState
-newState
+auto
+mapPopoverState
 =
 [
-&
-newValue
 ]
 (
+const
+nsAttrValue
+*
+value
 )
+-
+>
+PopoverAttributeState
 {
 if
 (
-newValue
+value
 )
 {
 MOZ_ASSERT
 (
-newValue
+value
 -
 >
 Type
@@ -3447,7 +3438,7 @@ static_cast
 PopoverAttributeKeyword
 >
 (
-newValue
+value
 -
 >
 GetEnumValue
@@ -3469,7 +3460,19 @@ PopoverAttributeState
 None
 ;
 }
+;
+PopoverAttributeState
+newState
+=
+mapPopoverState
 (
+GetParsedAttr
+(
+nsGkAtoms
+:
+:
+popover
+)
 )
 ;
 const
@@ -3488,15 +3491,19 @@ newState
 oldState
 )
 {
-EnsurePopoverData
+PopoverPseudoStateUpdate
 (
+false
+true
 )
-.
-SetPopoverAttributeState
+;
+if
+(
+IsPopoverOpen
 (
-newState
 )
-;
+)
+{
 HidePopoverInternal
 (
 true
@@ -3506,16 +3513,20 @@ IgnoreErrors
 )
 )
 ;
-if
-(
 newState
 =
-=
-GetPopoverAttributeState
+mapPopoverState
+(
+GetParsedAttr
 (
+nsGkAtoms
+:
+:
+popover
 )
 )
-{
+;
+}
 if
 (
 newState
@@ -3527,6 +3538,13 @@ PopoverAttributeState
 None
 )
 {
+if
+(
+GetPopoverData
+(
+)
+)
+{
 OwnerDoc
 (
 )
@@ -3538,6 +3556,7 @@ RemovePopoverFromTopLayer
 this
 )
 ;
+}
 ClearPopoverData
 (
 )
@@ -3553,16 +3572,18 @@ POPOVER_OPEN
 }
 else
 {
-PopoverPseudoStateUpdate
+EnsurePopoverData
 (
-false
-true
+)
+.
+SetPopoverAttributeState
+(
+newState
 )
 ;
 }
 }
 }
-}
 void
 nsGenericHTMLElement
 :
@@ -16277,24 +16298,8 @@ ErrorResult
 aRv
 )
 {
-const
-PopoverData
-*
-data
-=
-GetPopoverData
-(
-)
-;
 if
 (
-!
-data
-|
-|
-data
--
->
 GetPopoverAttributeState
 (
 )
@@ -16306,18 +16311,6 @@ PopoverAttributeState
 None
 )
 {
-MOZ_ASSERT
-(
-!
-HasAttr
-(
-nsGkAtoms
-:
-:
-popover
-)
-)
-;
 aRv
 .
 ThrowNotSupportedError
@@ -16337,20 +16330,11 @@ return
 false
 ;
 }
-MOZ_ASSERT
+if
 (
-HasAttr
+GetPopoverData
 (
-nsGkAtoms
-:
-:
-popover
 )
-)
-;
-if
-(
-data
 -
 >
 GetPopoverVisibilityState