Bug 1575596 - MathML Lengths: Do not accept numbers ending with a dot. r=emilio

See w3c/mathml#23
and https://groups.google.com/forum/#!topic/mozilla.dev.platform/wIjm9JjVHNg

This commit introduces a new preference option
mathml.legacy_number_syntax.disabled to disable legacy MathML numbers
(e.g. "1234.") that are not supported by CSS. This feature is now disabled by
default.

* test_bug553917.html is updated to check that such legacy values now cause an
  error message to be logged into the console when the feature is disabled.
* Legacy MathML features are now disabled for WPT mathml test in a global
  __dir__.ini file. Removing legacy numbers allow to pass
  mathml/relations/css-styling/lengths-2.html

Differential Revision: https://phabricator.services.mozilla.com/D42907

UltraBlame original commit: 8637163553058a09e835ee6d8e53a09735b1b1ec

Author: marco-c

dom/mathml/nsMathMLElement.cpp

@@ -1578,6 +1578,53 @@ c
 )
 ;
 }
+if
+(
+StaticPrefs
+:
+:
+mathml_legacy_number_syntax_disabled
+(
+)
+&
+&
+gotDot
+&
+&
+str
+[
+i
+-
+1
+]
+=
+=
+'
+.
+'
+)
+{
+if
+(
+!
+(
+aFlags
+&
+PARSE_SUPPRESS_WARNINGS
+)
+)
+{
+ReportLengthParseError
+(
+aString
+aDocument
+)
+;
+}
+return
+false
+;
+}
 nsresult
 errorCode
 ;

layout/mathml/tests/test_bug553917.html

@@ -217,6 +217,23 @@
 '
 )
 ;
+const
+allow_legacy_numbers
+=
+!
+SpecialPowers
+.
+getBoolPref
+(
+'
+mathml
+.
+legacy_number_syntax
+.
+disabled
+'
+)
+;
 var
 g_errorInfo
 =
@@ -1062,6 +1079,23 @@
 math
 >
 <
+mspace
+width
+=
+"
+12345
+.
+"
+/
+>
+<
+/
+math
+>
+<
+math
+>
+<
 mo
 minsize
 =
@@ -1105,6 +1139,7 @@
 allow_mathspace_names
 allow_mathspace_names
 allow_mathspace_names
+allow_legacy_numbers
 allow_nonzero_unitless_lengths
 ]
 args
@@ -1212,6 +1247,12 @@
 ]
 [
 "
+12345
+.
+"
+]
+[
+"
 17
 "
 ]
@@ -2427,6 +2468,23 @@
 math
 >
 <
+mspace
+width
+=
+"
+12345
+.
+"
+/
+>
+<
+/
+math
+>
+<
+math
+>
+<
 mmultiscripts
 >
 <

layout/reftests/mathml/reftest.list

@@ -132,6 +132,15 @@ pref
 (
 mathml
 .
+legacy_number_syntax
+.
+disabled
+false
+)
+pref
+(
+mathml
+.
 nonzero_unitless_lengths
 .
 disabled

modules/libpref/init/StaticPrefList.yaml

@@ -29670,6 +29670,48 @@ Whether
 to
 disable
 legacy
+MathML
+number
+values
+that
+are
+not
+valid
+CSS
+numbers
+#
+(
+e
+.
+g
+.
+"
+1234
+.
+"
+)
+-
+name
+:
+mathml
+.
+legacy_number_syntax
+.
+disabled
+type
+:
+bool
+value
+:
+true
+mirror
+:
+always
+#
+Whether
+to
+disable
+legacy
 names
 "
 small

testing/web-platform/meta/mathml/__dir__.ini

@@ -0,0 +1,39 @@
+prefs
+:
+[
+mathml
+.
+legacy_number_syntax
+.
+disabled
+:
+true
+mathml
+.
+mathsize_names
+.
+disabled
+:
+true
+mathml
+.
+mathspace_names
+.
+disabled
+:
+true
+mathml
+.
+mfrac_linethickness_names
+.
+disabled
+:
+true
+mathml
+.
+nonzero_unitless_lengths
+.
+disabled
+:
+true
+]

testing/web-platform/meta/mathml/presentation-markup/fractions/frac-linethickness-001.html.ini

@@ -7,17 +7,6 @@ linethickness
 .
 html
 ]
-prefs
-:
-[
-mathml
-.
-mathspace_names
-.
-disabled
-:
-true
-]
 [
 Negative
 ]