ignore std::locale exeception on non-existent "" locale

In 8b79c94af7f7cf2e5e5342294bc6e5a908cacabf changing to usage of C++ way
of setting the locale causes us to be terminated in case of usage of an
ungenerated locale as LC_ALL (or similar) – but we don't want to fail
here, we just want to carry on as before with setlocale which we call in
that case just for good measure.

apt-private/private-main.cc

@@ -18,7 +18,11 @@
 
 void InitLocale(APT_CMD const binary)				/*{{{*/
 {
-   std::locale::global(std::locale(""));
+   try {
+      std::locale::global(std::locale(""));
+   } catch (...) {
+      setlocale(LC_ALL, "");
+   }
    switch(binary)
    {
       case APT_CMD::APT:

methods/aptmethod.h

@@ -46,7 +46,11 @@ public:
    aptMethod(char const * const Binary, char const * const Ver, unsigned long const Flags) :
       pkgAcqMethod(Ver, Flags), Binary(Binary)
    {
-      std::locale::global(std::locale(""));
+      try {
+	 std::locale::global(std::locale(""));
+      } catch (...) {
+	 setlocale(LC_ALL, "");
+      }
    }
 };
 

test/integration/test-00-commands-have-help

@@ -11,6 +11,8 @@ configarchitecture 'amd64'
 # but it also checks if the binary can find all methods in the library.
 # The later is quite handy for manual testing of non-abibreaking changes
 export LD_BIND_NOW=1
+# german variant of klingon used for testing usage of non-existent l10n
+export LC_ALL=tlh_DE.UTF-8
 
 checkversionmessage() {
 	testsuccess grep '^apt .* (' ${1}-help.output