The double-bar delimiter does not stretch in MathJax 2.2

With the recent switch to MathJax 2.2, it seems that the double-bar delimiter (i.e. \|, or \lVert and \rVert) does not stretch when used with \left and \right (on my computer at least). The problem doesn't appear to occur with any other delimiter.

Consider the code

$$\begin{array}{cc} \| \frac{a}{b} \| & \left\| \frac{a}{b} \right\|\\ \{ \frac{a}{b} \} & \left\{ \frac{a}{b} \right\} \end{array}$$


Here it is as rendered by the site (this is not a screenshot): $$\begin{array}{cc} \| \frac{a}{b} \| & \left\| \frac{a}{b} \right\|\\ \{ \frac{a}{b} \} & \left\{ \frac{a}{b} \right\} \end{array}$$ Here it is as I see it in Chrome 26.0.1410.64 m (zoomed in 150%):

Here it is as I see it in Internet Explorer 10.0.9200.16540 (zoomed in 150%):

I'm using Windows 7 Home Premium 64-bit. For both Chrome and IE, I have cleared the cache and restarted the browser.

• I see it just fine, as rendered by the site. (FF-21.0/Arch Linux 64bit)
– Asaf Karagila Mod
May 20 '13 at 5:45
• I see the same bug (double bars are not resized) in current Chrome, FF, IE, and Opera (Windows Vista ... unfortunately). May 20 '13 at 6:26
• I see the bug in Safari 6.0.4 and in Firefox 20.0 under Mac OS 10.8.3. May 20 '13 at 8:35
• I see the same bug. About MathJax says "MathJax v2.2 using web TeX fonts". With one browser it also says: "Firefox v16.0 — woff or otf fonts"; with another: "Safari v5.1 — woff or otf fonts". I just checked; this does not appear under MathJax v2.1, so this appears to be a MathJax v2.2 bug. I will report this on the bug tracker.
– robjohn Mod
May 20 '13 at 11:59
• The issue also appears for me, using local STIX fonts on current Chrome, Win 7. So it appears to be a coding error rather than some rendering glitch. May 20 '13 at 12:22
• I see the bug in Chrome 26.0.1410.63 and Firefox 20.0 using Fedora 18. May 20 '13 at 16:55

• There was a change in how \left...\right is handled in v2.2, and there is a bug with some delimiters. It will be fixed in the next release. I could provide the powers that be with a patch to use in the meantime, if they are interested. May 20 '13 at 22:33