Clear user defined TeX macros from global state

lib/main.js

@@ -88,6 +88,8 @@ var queue = [];       // queue of typesetting requests of the form [data,callbac
 var data, callback, originalData;   // the current queue item
 var errors = [];      // errors collected durring the typesetting
 var ID = 0;           // id for this SVG element
+var userMacros = {};  // tracks user-defined macros during typesetting
+var userEnvironment = {}; // tracks user-defined environments during typesetting
 
 //
 //  The delimiters used for each of the input formats
@@ -416,6 +418,27 @@ function ConfigureMathJax() {
 
       });
 
+      //
+      //  Track user-defined macros and environment
+      //
+      MathJax.Hub.Register.StartupHook("TeX newcommand Ready",function () {
+        var TEX = MathJax.InputJax.TeX,
+            TEXDEF = TEX.Definitions;
+
+        var originalSetDef = TEX.Parse.prototype.setDef;
+        var originalSetEnv = TEX.Parse.prototype.setEnv;
+        TEX.Parse.Augment({
+          setDef: function (name,value) {
+            userMacros[name] = value;
+            return originalSetDef.apply(this, arguments);
+          },
+          setEnv: function (name,value) {
+            userEnvironment[name] = value;
+            return originalSetEnv.apply(this, arguments);
+          },
+        });
+      });
+
       //
       //  Reset the color extension after `autoload-all`
       //
@@ -715,6 +738,7 @@ function StartQueue() {
 function GetState(state) {
   var SVG = MathJax.OutputJax.SVG,
       TEX = MathJax.InputJax.TeX,
+      TEXDEF = TEX.Definitions,
       MML = MathJax.ElementJax.mml,
       AMS = MathJax.Extension["TeX/AMSmath"],
       HUB = MathJax.Hub, HTML = MathJax.HTML,
@@ -741,6 +765,38 @@ function GetState(state) {
     MML.SUPER.ID = ID = 0;
     MathJax.OutputJax.CommonHTML.ID = 0;
   }
+
+  // Clear any existing user-defined macros and environment, then load them from state
+  for (var name in userMacros) {
+    if (userMacros.hasOwnProperty(name)) {
+      delete TEXDEF.macros[name];
+    }
+  }
+  userMacros = {};
+  if (state && state.macros) {
+    for (var name in state.macros) {
+      if (state.macros.hasOwnProperty(name)) {
+        userMacros[name] = TEXDEF.macros[name] = state.macros[name];
+        // Set isUser on array, in case the state has been serialized and the property has been lost.
+        TEXDEF.macros[name].isUser = true;
+      }
+    }
+  }
+  for (var name in userEnvironment) {
+    if (userEnvironment.hasOwnProperty(name)) {
+      delete TEXDEF.environment[name];
+    }
+  }
+  userEnvironment = {};
+  if (state && state.environment) {
+    for (var name in state.environment) {
+      if (state.environment.hasOwnProperty(name)) {
+        userEnvironment[name] = TEXDEF.environment[name] = state.environment[name];
+        // Set isUser on array, in case the state has been serialized and the property has been lost.
+        TEXDEF.environment[name].isUser = true;
+      }
+    }
+  }
 }
 
 //
@@ -765,6 +821,7 @@ function ReturnResult(result) {
   if (state) {
     var AMS = MathJax.Extension["TeX/AMSmath"];
     var GLYPH = MathJax.OutputJax.SVG.BBOX.GLYPH;
+    var TEX = MathJax.InputJax.TeX;
     state.AMS.startNumber = AMS.startNumber;
     state.AMS.labels = AMS.labels;
     state.AMS.IDs = AMS.IDs;
@@ -773,6 +830,8 @@ function ReturnResult(result) {
     state.defs = GLYPH.defs;
     state.n = GLYPH.n;
     state.ID = ID;
+    state.macros = userMacros;
+    state.environment = userEnvironment;
   }
   serverState = STATE.READY;
   callback(result, originalData);