[OS X TeX] A problem with TeXShop

[Richard M. Koch]

> On Jun 3, 2017, at 6:46 PM, M. Tamer Özsu <ozsut at mac.com> wrote:
> 
> Hi Dick,
> 
> It happened again and the PDF file is attached.
> 
> Best.


Tamer,

I opened your pdf in Preview. It is a beamer document. I started scrolling, got a lot of blank pages, and then Preview completely hung.

Thus this is not a TeXShop bug. (I admit to a certain pleasure seeing that Preview crash on the first try.)

There are currently two bugs in PDFKit. Both bugs are new in Sierra, and do not occur with earlier operating systems. Both have been reported to Apple, with substantial examples. I described the first bug, but now your example is much more like the second problem. The second problem occurs mainly with Beamer documents, although we gave one or two non-beamer samples. A common symptom is that you scroll through a Beamer document, and suddenly come to an illustration which seems to trigger the problem. After that, you see many blank pages. The key symptom is that if you then scroll back to earlier pages which displayed correctly, many of these are also blank. Sometimes, but not always, the blank pages eventually result in a spinning cursor and hang.

There are three key discoveries about this problem:

a) If you open a defective pdf in Adobe Acrobat Reader, it will display correctly. If you then SAVE the document in Adobe Reader, the new pdf no longer causes problems in Preview or TeXShop.

b) The problem DOES NOT occur if you typeset with XeLaTeX.

c) The problem DOES NOT occur if you typeset with LuaLaTeX. 

Incidentally, b) and c) have mostly been tested with TeX Live 2017, during the pretest period. TeXLive 2017 and MacTeX 2017 will be released tomorrow.

Unless you are doing something very unusual, I recommend just switching to XeLaTeX or LuaLaTeX for this particular document, and any document causing similar problems. Both of these engines require UTF-8 input, so you may have slight problems if you save documents is another encoding. But after converting, everything
works as before except, NO CRASHES.

Dick Koch