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

--HG--
extra : moz-landing-system : lando

dom/mathml/nsMathMLElement.cpp

@@ -318,6 +318,13 @@ bool nsMathMLElement::ParseNumericValue(const nsString& aString,
     }
     number.Append(c);
   }
+  if (StaticPrefs::mathml_legacy_number_syntax_disabled() &&
+      gotDot && str[i - 1] == '.') {
+    if (!(aFlags & PARSE_SUPPRESS_WARNINGS)) {
+      ReportLengthParseError(aString, aDocument);
+    }
+    return false; // Number ending with a dot.
+  }
 
   // Convert number to floating point
   nsresult errorCode;

layout/mathml/tests/test_bug553917.html

@@ -19,6 +19,7 @@
       const allow_mathsize_names = !SpecialPowers.getBoolPref('mathml.mathsize_names.disabled');
       const allow_nonzero_unitless_lengths = !SpecialPowers.getBoolPref('mathml.nonzero_unitless_lengths.disabled');
       const allow_mathspace_names = !SpecialPowers.getBoolPref('mathml.mathspace_names.disabled');
+      const allow_legacy_numbers = !SpecialPowers.getBoolPref('mathml.legacy_number_syntax.disabled');
 
       var g_errorInfo = {
       /*<math><mroot></mroot></math>
@@ -71,6 +72,7 @@
         <math><mspace width="thickmathspace"/></math>
         <math><mspace width="verythickmathspace"/></math>
         <math><mspace width="veryverythickmathspace"/></math>
+        <math><mspace width="12345."/></math>
         <math><mo minsize="17">+</mo></math>
       */
         LengthParsingError : {
@@ -93,6 +95,7 @@
                      allow_mathspace_names,
                      allow_mathspace_names,
                      allow_mathspace_names,
+                     allow_legacy_numbers,
                      allow_nonzero_unitless_lengths,
                     ],
             args: [["2..0px"],
@@ -114,6 +117,7 @@
                    ["thickmathspace"],
                    ["verythickmathspace"],
                    ["veryverythickmathspace"],
+                   ["12345."],
                    ["17"]
                   ]
         },
@@ -230,6 +234,7 @@
     <math><mspace width="thickmathspace"/></math>
     <math><mspace width="verythickmathspace"/></math>
     <math><mspace width="veryverythickmathspace"/></math>
+    <math><mspace width="12345."/></math>
 
     <!-- MMultiscriptsErrors -->
     <math><mmultiscripts></mmultiscripts></math>

layout/reftests/mathml/reftest.list

@@ -4,7 +4,7 @@
 == 347496-1.xhtml 347496-1-ref.xhtml
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == 355548-1.xml 355548-1-ref.xml # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == 355548-2.xml 355548-2-ref.xml # Bug 1392106
-pref(mathml.nonzero_unitless_lengths.disabled,false) pref(mathml.mathsize_names.disabled,false) random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == 355548-3.xml 355548-3-ref.xml # Bug 1392106
+pref(mathml.legacy_number_syntax.disabled,false) pref(mathml.nonzero_unitless_lengths.disabled,false) pref(mathml.mathsize_names.disabled,false) random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == 355548-3.xml 355548-3-ref.xml # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == 355548-4.xml 355548-4-ref.xml # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == 355548-5.xml 355548-5-ref.xml # Bug 1392106
 == 370692-1.xhtml 370692-1-ref.xhtml

modules/libpref/init/StaticPrefList.yaml

@@ -4913,6 +4913,13 @@
 # Prefs starting with "mathml."
 #---------------------------------------------------------------------------
 
+# 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", "normal" and "big" for the
 # mathsize attribute.
 - name: mathml.mathsize_names.disabled

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

@@ -0,0 +1 @@
+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-002.html.ini

@@ -1,6 +1,4 @@
 [frac-linethickness-002.html]
-  prefs: [mathml.mathspace_names.disabled:true]
-
   [Negative]
     expected: FAIL