Incorrect escaping of curly braces in index entries

[cpitclaudel]

Problem

As explained in https://tex.stackexchange.com/questions/153291/index-unmatched-braces-in-latex, the LaTeX \index command requires matched braces: it's not correct to write this: \index{main \{}.

Unfortunately, that's the code that Sphinx generates for the following example:

.. index::
   single: main {

\index{main \{}\ignorespaces 

This problem happens in real life, ironically, when trying to index a collection of error messages from a compiler. One of the error messages is something like Unmatched delimiter: {, which trips Sphinx.

Error logs / results

Runaway argument?
{main \{}\ignorespaces 
! Paragraph ended before \@wrindex was complete.
<to be read again> 
                   \par 
l.71 

Expected results

As mentioned in the StackOverflow post above, the solution would be to escape backslashes more aggressively — using a separate macro definition, for example.

Environment info

• OS: GNU/Linux
• Python version: 3.5.2
• Sphinx version: 1.7.4

[tk0miya]

Fixed by #4987.
Thank you for reporting.

[cpitclaudel]

Thanks!