Don't escape \n, \r, or \t in toMathML text output. (Issue #847.)

Author: dpvc

unpacked/extensions/toMathML.js

@@ -43,7 +43,7 @@ MathJax.Hub.Register.LoadHook("[MathJax]/jax/element/mml/jax.js",function () {
         if (this.data[i]) {data.push(this.data[i].toMathML(SPACE))}
           else if (!this.isToken && !this.isChars) {data.push(SPACE+"<mrow />")}
       }
-      if (this.isToken) {return space + "<"+tag+attr+">"+data.join("")+"</"+tag+">"}
+      if (this.isToken || this.isChars) {return space + "<"+tag+attr+">"+data.join("")+"</"+tag+">"}
       if (inferred) {return data.join("\n")}
       if (data.length === 0 || (data.length === 1 && data[0] === ""))
         {return space + "<"+tag+attr+" />"}
@@ -109,7 +109,7 @@ MathJax.Hub.Register.LoadHook("[MathJax]/jax/element/mml/jax.js",function () {
         if (n <= 0xD7FF || 0xE000 <= n) {
           // Code points U+0000 to U+D7FF and U+E000 to U+FFFF.
           // They are directly represented by n.
-          if (n < 0x20 || n > 0x7E) {
+          if (n > 0x7E || (n < 0x20 && n !== 0x0A && n !== 0x0D && n !== 0x08)) {
             string[i] = "&#x"+n.toString(16).toUpperCase()+";";
           } else {
             var c =