Bug 1790009, part 3 - Implement special handling for operators using U+0338 and U+20D2. r=emilio

MathML Core specifies that operators containing a UTF-16 strings of
length 2 ending with U+0338 COMBINING LONG SOLIDUS OVERLAY or U+20D2
COMBINING LONG VERTICAL LINE OVERLAY should just use the properties of
the first character. This commit implements that behavior. It removes
obsolete entries that are superseded by this rule and modifies
updateOperatorDictionary.pl to ensure that no such entries are present.

Existing WPT test operator-dictionary-combining.html is already passing
after bug 1789583 because the operators tested use the default spacing.
So extend it to try operators with different spacing.

[1] https://w3c.github.io/mathml-core/#dfn-algorithm-to-determine-the-category-of-an-operator

Differential Revision: https://phabricator.services.mozilla.com/D157707

layout/mathml/mathfont.properties

@@ -1201,8 +1201,6 @@ operator.\u002B\u002B.prefix = lspace:0 rspace:2 # ++
 operator.\u002D\u002D.prefix = lspace:0 rspace:2 # --
 operator.\u002E\u002E.postfix = lspace:0 rspace:0 # ..
 operator.\u003B.postfix = lspace:0 rspace:0 separator # ;
-operator.\u003C\u20D2.infix = lspace:5 rspace:5 # <⃒
-operator.\u003E\u20D2.infix = lspace:5 rspace:5 # >⃒
 operator.\u007E.infix = lspace:2 rspace:2 stretchy direction:horizontal # ~
 operator.\u0332.postfix = lspace:0 rspace:0 stretchy accent direction:horizontal # _
 operator.\u03F6.infix = lspace:5 rspace:5 # greek reversed lunate epsilon symbol
@@ -1228,20 +1226,7 @@ operator.\u2234.infix = lspace:5 rspace:5 # ∴
 operator.\u2235.infix = lspace:5 rspace:5 # ∵
 operator.\u223D\u0331.infix = lspace:3 rspace:3 # reversed tilde with underline
 operator.\u223F.infix = lspace:3 rspace:3 # sine wave
-operator.\u2242\u0338.infix = lspace:5 rspace:5 # ≂̸
-operator.\u224E\u0338.infix = lspace:5 rspace:5 # ≎̸
-operator.\u224F\u0338.infix = lspace:5 rspace:5 # ≏̸
-operator.\u2266\u0338.infix = lspace:5 rspace:5 # ≧̸
-operator.\u226A\u0338.infix = lspace:5 rspace:5 # ≪̸
-operator.\u226B\u0338.infix = lspace:5 rspace:5 # ≫̸
-operator.\u227F\u0338.infix = lspace:5 rspace:5 # ≿̸
-operator.\u2282\u020D2.infix = lspace:5 rspace:5 # ⊂⃒
-operator.\u2282\u20D2.infix = lspace:5 rspace:5 # subset of with vertical line
-operator.\u2283\u020D2.infix = lspace:5 rspace:5 # ⊃⃒
-operator.\u2283\u20D2.infix = lspace:5 rspace:5 # superset of with vertical line
 operator.\u228E.prefix = lspace:1 rspace:2 largeop movablelimits symmetric direction:vertical # ⊎
-operator.\u228F\u0338.infix = lspace:5 rspace:5 # ⊏̸
-operator.\u2290\u0338.infix = lspace:5 rspace:5 # ⊐̸
 operator.\u2295.prefix = lspace:0 rspace:3 largeop movablelimits symmetric direction:vertical # ⊕
 operator.\u2296.prefix = lspace:0 rspace:3 largeop movablelimits symmetric direction:vertical # ⊖
 operator.\u2297.prefix = lspace:0 rspace:3 largeop movablelimits symmetric direction:vertical # ⊗
@@ -1343,8 +1328,6 @@ operator.\u29CA.infix = lspace:3 rspace:3 # triangle with dot above
 operator.\u29CB.infix = lspace:3 rspace:3 # triangle with underbar
 operator.\u29CC.infix = lspace:3 rspace:3 # s in triangle
 operator.\u29CD.infix = lspace:3 rspace:3 # triangle with serifs at bottom
-operator.\u29CF\u0338.infix = lspace:5 rspace:5 # ⧏̸
-operator.\u29D0\u0338.infix = lspace:5 rspace:5 # ⧐̸
 operator.\u29D8.infix = lspace:3 rspace:3 # left wiggly fence
 operator.\u29D9.infix = lspace:3 rspace:3 # right wiggly fence
 operator.\u29DB.infix = lspace:3 rspace:3 # right double wiggly fence
@@ -1367,15 +1350,6 @@ operator.\u29F2.infix = lspace:3 rspace:3 # error-barred white circle
 operator.\u29F3.infix = lspace:3 rspace:3 # error-barred black circle
 operator.\u29FE.infix = lspace:4 rspace:4 # tiny
 operator.\u29FF.infix = lspace:4 rspace:4 # miny
-operator.\u2A7D\u0338.infix = lspace:5 rspace:5 # ⩽̸
-operator.\u2A7E\u0338.infix = lspace:5 rspace:5 # ⩾̸
-operator.\u2AA1\u0338.infix = lspace:5 rspace:5 # ⪡̸
-operator.\u2AA2\u0338.infix = lspace:5 rspace:5 # ⪢̸
-operator.\u2AAF\u0338.infix = lspace:5 rspace:5 # ⪯̸
-operator.\u2AB0\u0338.infix = lspace:5 rspace:5 # ⪰̸
-operator.\u2AC5\u0338.infix = lspace:5 rspace:5 # ⫅̸
-operator.\u2AC6\u0338.infix = lspace:5 rspace:5 # ⫅̸
-operator.\u2ADD\u0338.infix = lspace:5 rspace:5 # nonforking with slash
 operator.\u2AEC.infix = lspace:5 rspace:5 # double stroke not sign
 operator.\u2AED.infix = lspace:5 rspace:5 # reversed double stroke not sign
 operator.\u2AEF.infix = lspace:5 rspace:5 # vertical line with circle above

layout/mathml/nsMathMLOperators.cpp

@@ -323,6 +323,16 @@ bool nsMathMLOperators::LookupOperator(const nsString& aOperator,
     return false;
   }
 
+  // Ignore the combining "negation" suffix for 2-character strings.
+  // https://w3c.github.io/mathml-core/#dfn-algorithm-to-determine-the-category-of-an-operator
+  if (aOperator.Length() == 2 &&
+      (aOperator[1] == 0x0338 || aOperator[1] == 0x20D2)) {
+    nsAutoString newOperator;
+    newOperator.Append(aOperator[0]);
+    return LookupOperator(newOperator, aForm, aFlags, aLeadingSpace,
+                          aTrailingSpace);
+  }
+
   if (!gGlobalsInitialized) {
     InitOperatorGlobals();
   }

layout/mathml/updateOperatorDictionary.pl

@@ -141,6 +141,12 @@ if ($ARGV[0] eq "check") {
             print $file_syntax_errors "error: \"$key\" has more than 2 characters\n";
         }
 
+        if ($key =~ /\\u20D2\./ || $key =~ /\\u0338\./) {
+            $valid = 0;
+            $nb_errors++;
+            print $file_syntax_errors "error: \"$key\" ends with character U+20D2 or U+0338\n";
+        }
+
         @moz = @{ $moz_hash{$key} };
         $entry = &generateEntry($key, @moz);
         $valid = 1;

testing/web-platform/tests/mathml/presentation-markup/operators/operator-dictionary-combining.html

@@ -33,7 +33,12 @@
       var epsilon = 1;
       var emToPx = 25;
 
-      ["equal", "vertical_bar"].forEach(id => {
+      [
+          "equal",
+          "vertical_bar",
+          "left_normal_factor_semidirect_product",
+          "there_exists",
+      ].forEach(id => {
           var div = document.getElementById(id);
           var ref = div.getElementsByClassName("reference")[0];
           var totalSpaceRef = spaceBetween(ref, 0, 2);
@@ -104,5 +109,51 @@
       </math>
     </p>
   </div>
+  <div id="left_normal_factor_semidirect_product">
+    <p>
+      <math class="reference">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">⋉</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+    <p>
+      <math class="combining">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">⋉&#x338;</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+    <p>
+      <math class="combining">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">⋉&#x20D2;</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+  </div>
+  <div id="there_exists">
+    <p>
+      <math class="reference">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">∃</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+    <p>
+      <math class="combining">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">∃&#x338;</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+    <p>
+      <math class="combining">
+        <mn>&nbsp;</mn>
+        <mo stretchy="false">∃&#x20D2;</mo>
+        <mn>&nbsp;</mn>
+      </math>
+    </p>
+  </div>
 </body>
 </html>