Last modified: 2014-11-18 18:07:26 UTC
<math>f(x)\delta(x-a) = f(a)\delta(x-a)</math> renders incorrectly to f(x)δ(x − a) = f(a)δ(x − a)- (mind the dash at the end) <math>f(x)\delta(x-a) = f(a)\delta(x-a) </math> (mind the space at the end) renders correctly to f(x)δ(x − a) = f(a)δ(x − a) to be seen on http://cs.wikipedia.org/w/index.php?title=Diracova_delta_funkce&oldid=778611 and following revision occurs while "simple math as html, otherwise as png" checked, if "always png" checked, it's rendered properly
*** Bug 7386 has been marked as a duplicate of this bug. ***
I cannot be sure how it was few days ago but now it renders the extra dash regardless of spaces (see http://bg.wikipedia.org/w/Овал_на_Касини as per #7386).
ISTR that this is an old bug which was resolved long ago. Since dewiki uses this kind of in-line equations heavily and people have already started using workarounds, I changed severity back to normal.
This is a really annoying bug. I have been using workarounds. However I would much prefer the bug to be fixed! The problem is that when it eventually does get fixed, the formulae with the workarounds may not render correctly!
Created attachment 2419 [details] patch for math/render.ml fixing the problem When using dvipng, there is no temporary .ps file which could be deleted. This results in a hyphen signalling "some error" (catch-all case in texvc.ml).
Committed revision 16890.
Problem persists, see <http://de.wikipedia.org/wiki/Portal_Diskussion:Mathematik#Mathe_bug.3F>. This is *not* a caching issue. Unfortunately, I cannot reproduce the problem on my local MW installation once the patch is applied.
One way to trigger the bug is using superscripts. Still quite erratic, eg. <math>1^a</math> triggers the error, while <math>0^x</math> not. See http://hu.wikipedia.org/w/index.php?title=User:Tgr/teszt&oldid=914553 for some more test cases.
(In reply to comment #7) > Problem persists, see > <http://de.wikipedia.org/wiki/Portal_Diskussion:Mathematik#Mathe_bug.3F>. The patch was not installed on wikipedia.org, it is now.
(In reply to comment #9) > The patch was not installed on wikipedia.org, it is now. It is still re-producing at bg.wiki (please see the first formula at http://bg.wikipedia.org/wiki/%D0%9E%D0%B2%D0%B0%D0%BB_%D0%BD%D0%B0_%D0%9A%D0%B0%D1%81%D0%B8%D0%BD%D0%B8)
(In reply to comment #10) > It is still re-producing at bg.wiki (please see the first formula at > http://bg.wikipedia.org/wiki/%D0%9E%D0%B2%D0%B0%D0%BB_%D0%BD%D0%B0_%D0%9A%D0%B0%D1%81%D0%B8%D0%BD%D0%B8) OK, I've got a notification by bugzilla that it is fixed. Rushing to the article with the rendering problem I've got the dash again (if you cannot open the long URL above try [[:en:Cassini oval]] and follow the first interwiki, bg:). The first formula renders as " = a4-, " and removals/additions of spaces do not help.
The bug is fixed, the problem for your part is that math images are cached indefinite. There are only two ways to rerender the image, the fist one is to purge the math database (contains millions of entries, so the devs have said no), the second way is to manipulate the MD5 sum, for example add a \, or simlar to the end (not a nice way, but at the moment it's the only way).
(In reply to comment #12) > The bug is fixed, the problem for your part is that math images are cached > indefinite. There are only two ways to rerender the image, the fist one is to > purge the math database (contains millions of entries, so the devs have said > no), the second way is to manipulate the MD5 sum, for example add a \, or simlar > to the end (not a nice way, but at the moment it's the only way). OK, this explains a lot. So (for me) in general the answer is there is no fix, and is not going to be one in the foreseeable future. Addition of several spaces is altering the sum, and is fine. Addition of "\," is not the same as it forces the rendering engine to use image instead of HTML. Moreover it was described that the problem comes up if and only if the rendering is done as HTML.
(In reply to comment #13) > (In reply to comment #12) > > The bug is fixed, the problem for your part is that math images are cached > > indefinite. There are only two ways to rerender the image, the fist one is to > > purge the math database (contains millions of entries, so the devs have said > > no), the second way is to manipulate the MD5 sum, for example add a \, or simlar > > to the end (not a nice way, but at the moment it's the only way). > > OK, this explains a lot. So (for me) in general the answer is there is no fix, > and is not going to be one in the foreseeable future. Addition of several spaces > is altering the sum, and is fine. Addition of "\," is not the same as it forces > the rendering engine to use image instead of HTML. Moreover it was described > that the problem comes up if and only if the rendering is done as HTML. Oh, my bad, what I tested was that changing 'a' to 'b'. And the caching of the html is the same, so no there is nothing to be done, I'm afraid.
Presumably the cache expires after a while. *** This bug has been marked as a duplicate of 7768 ***
Re-marking this *fixed*. Will see what can be done about clearing affected items, which is separate from the issue being fixed.
*** Bug 9580 has been marked as a duplicate of this bug. ***
