*The issue :*

When using Zathura as a viewer, Zathura fails to launch with the default 
View command defined by auctex in tex.el when both of the following  
conditions are true :

- synctex is used

- the .tex file name has spaces in its filename


*My config : *emacs 25.3.2 auctex 12.1.1 and Zathura 0.3.5 under 
elementaryos

The problem was reproduced on a fresh install of antergos with emacs 
25.3.1 auctex 12.1.1 and Zathura 0.3.9


*The possible cause :*

In tex.el Zathura is launched with the following parameters when using 
synctex :

     (mode-io-correlate " --synctex-forward %n:0:%b -x \"emacsclient 
+%{line} %{input}\""))

%b is the .tex filename, which is unquoted.

*
*

*The possible solution :*

The problem is solved, as far as I can tell, by replacing %b with: \"%b\"


Yours sincerely,

Arach HIRMANPOUR