From 0fb87f3deaedd097a8f65733d753eae1cd669324 Mon Sep 17 00:00:00 2001
From: "Davide P. Cervone" <dpvc@union.edu>
Date: Wed, 15 Apr 2015 19:55:23 -0400
Subject: [PATCH] Right-justify prescripts in mmultiscript elements.  Resolves
 issue #1072.

---
 .../output/HTML-CSS/autoload/mmultiscripts.js | 37 +++++++++++++++----
 .../jax/output/SVG/autoload/mmultiscripts.js  |  7 +++-
 2 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/unpacked/jax/output/HTML-CSS/autoload/mmultiscripts.js b/unpacked/jax/output/HTML-CSS/autoload/mmultiscripts.js
index c80305b7c..b92fbdabb 100644
--- a/unpacked/jax/output/HTML-CSS/autoload/mmultiscripts.js
+++ b/unpacked/jax/output/HTML-CSS/autoload/mmultiscripts.js
@@ -120,25 +120,48 @@ MathJax.Hub.Register.StartupHook("HTML-CSS Jax Ready",function () {
       var i = 1, m = this.data.length, W = 0;
       for (var k = 0; k < 4; k += 2) {
         while (i < m && this.data[i].type !== "mprescripts") {
+          var box = [null,null,null,null];
           for (var j = k; j < k+2; j++) {
             if (this.data[i] && this.data[i].type !== "none") {
               if (!BOX[j]) {
                 BOX[j] = HTMLCSS.createBox(stack); BOX[j].bbox = this.HTMLemptyBBox({});
                 if (W) {HTMLCSS.createBlank(BOX[j],W); BOX[j].bbox.w = BOX[j].bbox.rw = W}
               }
-              this.data[i].toHTML(BOX[j]); this.HTMLcombineBBoxes(this.data[i],BOX[j].bbox);
+              box[j] = this.data[i].toHTML(BOX[j]);
             }
             i++;
           }
+          var isPre = (k === 2);
           sub = BOX[k]; sup = BOX[k+1];
           if (sub && sup) {
-            if (sub.bbox.w < sup.bbox.w) {
-              HTMLCSS.createBlank(sub,sup.bbox.w-sub.bbox.w);
-              sub.bbox.w = sup.bbox.w; sub.bbox.rw = Math.max(sub.bbox.w,sub.bbox.rw);
-            } else if (sub.bbox.w > sup.bbox.w) {
-              HTMLCSS.createBlank(sup,sub.bbox.w-sup.bbox.w);
-              sup.bbox.w = sub.bbox.w; sup.bbox.rw = Math.max(sup.bbox.w,sup.bbox.rw);
+            var w = box[k+1].bbox.w - box[k].bbox.w;
+            if (w > 0) {
+              if (isPre) {
+                box[k].style.paddingLeft = HTMLCSS.Em(w/box[k].scale);
+                BOX[k].w += w;
+              } else {
+                HTMLCSS.createBlank(sub,w);
+              }
+            } else if (w < 0) {
+              if (isPre) {
+                box[k+1].style.paddingLeft = HTMLCSS.Em(-w/box[k+1].scale);
+                BOX[k+1].w += -w;
+              } else {
+                HTMLCSS.createBlank(sup,-w);
+              }
             }
+            this.HTMLcombineBBoxes(box[k],sub.bbox);
+            this.HTMLcombineBBoxes(box[k+1],sup.bbox);
+            if (w > 0) {
+              sub.bbox.w = sup.bbox.w;
+              sub.bbox.rw = Math.max(sub.bbox.w,sub.bbox.rw);
+            } else if (w < 0) {
+              sup.bbox.w = sub.bbox.w;
+              sup.bbox.rw = Math.max(sup.bbox.w,sup.bbox.rw);
+            }
+          } else {
+            if (sub) this.HTMLcombineBBoxes(box[k],sub.bbox);
+            if (sup) this.HTMLcombineBBoxes(box[k+1],sup.bbox);
           }
           if (sub) {W = sub.bbox.w} else if (sup) {W = sup.bbox.w}
         }
diff --git a/unpacked/jax/output/SVG/autoload/mmultiscripts.js b/unpacked/jax/output/SVG/autoload/mmultiscripts.js
index ac2ea67d9..000a62e95 100644
--- a/unpacked/jax/output/SVG/autoload/mmultiscripts.js
+++ b/unpacked/jax/output/SVG/autoload/mmultiscripts.js
@@ -101,13 +101,18 @@ MathJax.Hub.Register.StartupHook("SVG Jax Ready",function () {
       var i = 1, m = this.data.length, W = 0;
       for (var k = 0; k < 4; k += 2) {
         while (i < m && this.data[i].type !== "mprescripts") {
+          var box = [null,null,null,null];
           for (var j = k; j < k+2; j++) {
             if (this.data[i] && this.data[i].type !== "none") {
               if (!BOX[j]) {BOX[j] = SVG.BBOX.G()}
-              BOX[j].Add(this.data[i].toSVG().With({x:W}));
+              box[j] = this.data[i].toSVG();
             }
             i++;
           }
+          var isPre = (k === 2);
+          if (isPre) W += Math.max((box[k]||{w:0}).w,(box[k+1]||{w:0}).w);
+          if (box[k])   BOX[k].Add(box[k].With({x:W-(isPre?box[k].w:0)}));
+          if (box[k+1]) BOX[k+1].Add(box[k+1].With({x:W-(isPre?box[k+1].w:0)}));
           sub = BOX[k]||{w:0}; sup = BOX[k+1]||{w:0};
           sub.w = sup.w = W = Math.max(sub.w,sup.w);
         }