[LyX/master] Fix InsetListings::getCaption() for std::regex

[Georg Baum]

commit dfe3a7d9fc57911b920eb3bc5f7fe7d4b7397823
Author: Georg Baum <b...@lyx.org>
Date:   Sun Nov 22 17:43:10 2015 +0100

    Fix InsetListings::getCaption() for std::regex
    
    Back references in the format string of regex_replace use the syntax $n both
    in std::regex and in boost::regex for the default format. Boost seems to
    support the syntax \n in addition, but it is not documented at
    
http://www.boost.org/doc/libs/master/libs/regex/doc/html/boost_regex/format.html.
    Therefore it is a good idea to use $n also for boost.

diff --git a/src/insets/InsetListings.cpp b/src/insets/InsetListings.cpp
index 9c7daf2..91125d8 100644
--- a/src/insets/InsetListings.cpp
+++ b/src/insets/InsetListings.cpp
@@ -418,7 +418,7 @@ docstring InsetListings::getCaption(OutputParams const & 
runparams) const
        //
        // NOTE that } is not allowed in blah2.
        regex const reg("(.*)\\\\label\\{(.*?)\\}(.*)");
-       string const new_cap("\\1\\3},label={\\2");
+       string const new_cap("$1$3},label={$2");
        return from_utf8(regex_replace(to_utf8(cap), reg, new_cap));
 }
 
diff --git a/src/tests/check_ListingsCaption.cpp 
b/src/tests/check_ListingsCaption.cpp
index 2df43e8..874e3d6 100644
--- a/src/tests/check_ListingsCaption.cpp
+++ b/src/tests/check_ListingsCaption.cpp
@@ -23,7 +23,7 @@ string test_ListingsCaption(string const & cap)
        //
        // NOTE that } is not allowed in blah2.
        regex const reg("(.*)\\\\label\\{(.*?)\\}(.*)");
-       string const new_cap("\\1\\3},label={\\2");
+       string const new_cap("$1$3},label={$2");
        return regex_replace(cap, reg, new_cap);
 }