From b1abd818bdbd82f2490d7fc8b6a8279859ef8c1a Mon Sep 17 00:00:00 2001
From: "Davide P. Cervone" <dpvc@union.edu>
Date: Wed, 3 Oct 2012 06:22:19 -0400
Subject: [PATCH] Fix problem with adding widths when child node is empty that
 causes linebreaking to produce math processing errors.  (Reported by
 StackExchange community.)

---
 unpacked/jax/output/HTML-CSS/autoload/multiline.js | 12 +++++++-----
 unpacked/jax/output/SVG/autoload/multiline.js      |  8 +++++---
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/unpacked/jax/output/HTML-CSS/autoload/multiline.js b/unpacked/jax/output/HTML-CSS/autoload/multiline.js
index 4b12b92cf..639d0b35e 100644
--- a/unpacked/jax/output/HTML-CSS/autoload/multiline.js
+++ b/unpacked/jax/output/HTML-CSS/autoload/multiline.js
@@ -168,11 +168,13 @@ MathJax.Hub.Register.StartupHook("HTML-CSS Jax Ready",function () {
       return better;
     },
     HTMLaddWidth: function (i,info,scanW) {
-      var span = this.data[i].HTMLspanElement();
-      scanW += span.bbox.w;
-      if (span.style.paddingLeft)  {scanW += HTMLCSS.unEm(span.style.paddingLeft)}
-      if (span.style.paddingRight) {scanW += HTMLCSS.unEm(span.style.paddingRight)}
-      info.W = info.scanW = scanW; info.w = 0;
+      if (this.data[i]) {
+        var span = this.data[i].HTMLspanElement();
+        scanW += span.bbox.w;
+        if (span.style.paddingLeft)  {scanW += HTMLCSS.unEm(span.style.paddingLeft)}
+        if (span.style.paddingRight) {scanW += HTMLCSS.unEm(span.style.paddingRight)}
+        info.W = info.scanW = scanW; info.w = 0;
+      }
       return scanW;
     },
     
diff --git a/unpacked/jax/output/SVG/autoload/multiline.js b/unpacked/jax/output/SVG/autoload/multiline.js
index 3a4df84bd..3025cb044 100644
--- a/unpacked/jax/output/SVG/autoload/multiline.js
+++ b/unpacked/jax/output/SVG/autoload/multiline.js
@@ -171,9 +171,11 @@ MathJax.Hub.Register.StartupHook("SVG Jax Ready",function () {
       return better;
     },
     SVGaddWidth: function (i,info,scanW) {
-      var svg = this.data[i].SVGdata;
-      scanW += svg.w + svg.x; if (svg.X) {scanW += svg.X}
-      info.W = info.scanW = scanW; info.w = 0;
+      if (this.data[i]) {
+        var svg = this.data[i].SVGdata;
+        scanW += svg.w + svg.x; if (svg.X) {scanW += svg.X}
+        info.W = info.scanW = scanW; info.w = 0;
+      }
       return scanW;
     },