Make sure height is above depth when making spaces and rules in HTML-CSS and SVG output

unpacked/jax/output/HTML-CSS/jax.js

@@ -894,7 +894,8 @@
       return space;
     },
     createSpace: function (span,h,d,w,color) {
-      var H = this.Em(Math.max(0,h+d)), D = this.Em(-d);
+      if (h < -d) {d = -h} // make sure h is above d
+      var H = this.Em(h+d), D = this.Em(-d);
       if (this.msieInlineBlockAlignBug) {D = this.Em(HTMLCSS.getHD(span.parentNode).d-d)}
       if (span.isBox || span.className == "mspace") {
         var scale = (span.scale == null ? 1 : span.scale);
@@ -925,6 +926,7 @@
       return span;
     },
     createRule: function (span,h,d,w,color) {
+      if (h < -d) {d = -h} // make sure h is above d
       var min = HTMLCSS.TeX.min_rule_thickness, f = 1;
       // If rule is very thin, make it at least min_rule_thickness so it doesn't disappear
       if (w > 0 && w*this.em < min) {w = min/this.em}
@@ -942,6 +944,7 @@
       return rule;
     },
     createFrame: function (span,h,d,w,t,style) {
+      if (h < -d) {d = -h} // make sure h is above d
       var T = (this.msieBorderWidthBug ? 0 : 2*t);
       var H = this.Em(h+d-T), D = this.Em(-d-t), W = this.Em(w-T);
       var B = this.Em(t)+" "+style;

unpacked/jax/output/SVG/jax.js

@@ -1411,6 +1411,7 @@
         svg.d = SVG.length2em(values.depth,mu)  / svg.scale;
 	svg.w = svg.r = SVG.length2em(values.width,mu) / svg.scale;
         if (svg.w < 0) {svg.x = svg.w; svg.w = svg.r = 0}
+        if (svg.h < -svg.d) {svg.d = -svg.h}
         svg.l = 0; svg.Clean();
         this.SVGhandleColor(svg);
         this.SVGsaveData(svg);