From 3d22d9396614783550f9e2f4af954eb9a080d1f1 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 4 Apr 2016 22:52:41 +0530
Subject: [PATCH] E-book viewer: When displaying an EPUB 3 document that uses
 epub:switch to provide a fallback for MathML content, prevent both the MathML
 and fallback from being shown together.

PDF Output: When displaying an EPUB 3 document that uses epub:switch to provide a fallback for MathML content, prevent both the MathML and fallback from being rendered together.
---
 resources/compiled_coffeescript.zip           | Bin 105783 -> 106998 bytes
 src/calibre/ebooks/oeb/display/mathjax.coffee |  24 ++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/resources/compiled_coffeescript.zip b/resources/compiled_coffeescript.zip
index cf97c94acf927e137e0ff096e10bc43cc3317b5d..5532c771a9b381b38b8b03e8348f4ba1282d021a 100644
GIT binary patch
delta 924
zcmZuvO-vI(7~Ls~P(uR<f|Q17qtKG2?W!#;&_qK5BwCPz7aD@w>1<ml{n>5V10{Me
zF(f7?PU1jY4SJJ<F`{7nxu}U;)Uz=j;Ar&V#i%jFX<;cL%p{ZD_r9O^y_vNamA~Fr
zJ~l5K(CYP}zTEicdL75D*R42~=Z`kYcsenIC#J=8WI_^Sv7m^i6swIqe3orEh$EwK
zi~{1Jl*q(Gr8FK!c^JcS9>x>#9Yn?w4`r-mVrhkkib^(Cc!LEeGr=B3jiyn=Vk0#v
zGp#a$TC()fd{t4Qk0nTf=y<Ol?kueyqXK*2a%)B~%?d83AO<O_U5d&|x<3+)h02u5
zelfHn8=T$k0AW;Oklh?hATc&9PGjiv`Cvy$DH0Xjp+%D`Pg{|UQ<<oYLtSwesU$^I
z<ckTGNIISDaX3^}wX0|B2|4T#yk3vP&ulFn{)-l^k~SUO;~`Uxww036^TuPv5N&vS
zGNVMSh?v8zgAlV}cO)OAID{pUS-vY;Yqh^t>QmDZ2#a1J^5LY}z&t3MYP+3nAvxT9
z0>T+lhLfes6?U&v=+zStZXjQ9ovAp246T!_kaIhXeQC|e`*-d2+g&s$Fge~!wj>ik
zq%CV9e7KhU8>uEE;d&-#&StgQ$j{3rQj@Krul=Cq&JAE7xBfJeA5ZF6PObVk_q||x
zZ2<&yEw4yozLDHqtD=7wKxf5LJ0QvV2Kqe*s%ZZr=+tfW(ZnJcJTx!>IQlXV+UREn
zSNJ9X&5r?7^Q8-iD>=6GY=6^n-0wW#wsf-=npy-#T74IE(FX-^oDS!}J^H)=hUlX)
zpr_~Z;47Uf0E5-#afL#`(@voqb$idc1ZU7CdEA26>F&lZx7#C%ND@RzqW24+iJA&v
KxTwwr=Kcfa&nZX%

delta 251
zcmex%m~HzmwhfA__`F=JJ#P2dadYxAFmUp2)?d}hJ^9|&+|5sR`94CEoNhmtF`6lQ
z`}DxMjH1&w&Sf-WeyGSexu8>I`hkUv9MhTRF={a>SxncP$LP+~?l`@C9-}u)T@)k3
zbe#o^GU5T=tZWQGzy*Y_m>3u=r!zAAW2&AmxR6m~`sq20eACnBGfn^*Wjg)90-z0c
z3mBhImzvASJ-v1zqqA9VVo63;VufB-v67X7l98!_xnZKAWr{_Lv00j#iBVFrSyHN*
nv6-2fg^@*yk-4F{k%@(Y$#lp0jN;S3&1dwO&NH9UjIkB~&q_~F

diff --git a/src/calibre/ebooks/oeb/display/mathjax.coffee b/src/calibre/ebooks/oeb/display/mathjax.coffee
index 6c24a31939..8a635d2f65 100644
--- a/src/calibre/ebooks/oeb/display/mathjax.coffee
+++ b/src/calibre/ebooks/oeb/display/mathjax.coffee
@@ -74,9 +74,33 @@ class MathJax
 
         if script != null or document.getElementsByTagName('math').length > 0
             this.math_present = true
+            this.remove_math_fallbacks()
             this.load_mathjax(user_config, is_windows)
         return this.math_present
 
+    remove_math_fallbacks: () ->
+        # localName no longer exists in Chrome >= 46 so you will need to
+        # investigate a proper solution for this in modern browsers. Probably
+        # use document.evaluate() and node.tagName? IE does not support
+        # document.evaluate() but Edge may or may not, you will need to
+        # experiment
+        for sw in document.getElementsByTagName("epub:switch")
+            non_math = []
+            found_math = false
+            c = sw.firstChild
+            while c
+                if c.localName == 'epub:case'
+                    if c.getAttribute('required-namespace') == "http://www.w3.org/1998/Math/MathML"
+                        found_math = c
+                    else
+                        non_math.push(c)
+                else if c.localName == 'epub:default'
+                    non_math.push(c)
+                c = c.nextSibling
+            if found_math
+                for c in non_math
+                    c.style.display = 'none'
+
     after_resize: () ->
         if not this.math_present or this.hub == null
             return