Fix startup crash when using a locale boost does not like

There are various locale related bugs in various versions of boost,
where exceptions are thrown in boost::filesystem APIs when the
current locale is not to boost's liking. It's not clear what "not
to boost's liking" means in detail, though "en" and "en_US.UTF-8"
are not to its liking.

Fix it by running a test function that's known to throw in such
a case, and resetting LANG and LC_ALL to C if an exception is
thrown. In simplewallet, the locale is queried before that so the
correct translations will still be used.

src/blockchain_utilities/blockchain_dump.cpp

@@ -94,6 +94,8 @@ int main(int argc, char* argv[])
   uint32_t log_level = 0;
   uint64_t block_stop = 0;
 
+  tools::sanitize_locale();
+
   boost::filesystem::path default_data_path {tools::get_default_data_dir()};
   boost::filesystem::path default_testnet_data_path {default_data_path / "testnet"};
   boost::filesystem::path output_file_path;

src/blockchain_utilities/blockchain_export.cpp

@@ -42,6 +42,8 @@ int main(int argc, char* argv[])
   uint64_t block_stop = 0;
   bool blocks_dat = false;
 
+  tools::sanitize_locale();
+
   boost::filesystem::path default_data_path {tools::get_default_data_dir()};
   boost::filesystem::path default_testnet_data_path {default_data_path / "testnet"};
   boost::filesystem::path output_file_path;

src/blockchain_utilities/blockchain_import.cpp

@@ -538,6 +538,8 @@ int main(int argc, char* argv[])
   std::string m_config_folder;
   std::string db_arg_str;
 
+  tools::sanitize_locale();
+
   boost::filesystem::path default_data_path {tools::get_default_data_dir()};
   boost::filesystem::path default_testnet_data_path {default_data_path / "testnet"};
   std::string import_file_path;

src/common/util.cpp

@@ -43,6 +43,7 @@ using namespace epee;
 #else 
 #include <sys/utsname.h>
 #endif
+#include <boost/filesystem.hpp>
 
 
 namespace tools
@@ -389,4 +390,22 @@ std::string get_nix_version_display_string()
 #endif
     return std::error_code(code, std::system_category());
   }
+
+  bool sanitize_locale()
+  {
+    // boost::filesystem throws for "invalid" locales, such as en_US.UTF-8, or kjsdkfs,
+    // so reset it here before any calls to it
+    try
+    {
+      boost::filesystem::path p {std::string("test")};
+      p /= std::string("test");
+    }
+    catch (...)
+    {
+      setenv("LC_ALL", "C", 1);
+      setenv("LANG", "C", 1);
+      return true;
+    }
+    return false;
+  }
 }

src/common/util.h

@@ -88,6 +88,8 @@ namespace tools
    */
   std::error_code replace_file(const std::string& replacement_name, const std::string& replaced_name);
 
+  bool sanitize_locale();
+
   inline crypto::hash get_proof_of_trust_hash(const nodetool::proof_of_trust& pot)
   {
     std::string s;

src/daemon/main.cpp

@@ -54,6 +54,8 @@ int main(int argc, char const * argv[])
 		_note_c("dbg/main", "Begin of main()");
 		// TODO parse the debug options like set log level right here at start
 
+    tools::sanitize_locale();
+
     epee::string_tools::set_module_name_and_folder(argv[0]);
 
     // Build argument description

src/simplewallet/simplewallet.cpp

@@ -2164,6 +2164,9 @@ int main(int argc, char* argv[])
 
   //TRY_ENTRY();
 
+  std::string lang = i18n_get_language();
+  tools::sanitize_locale();
+
   string_tools::set_module_name_and_folder(argv[0]);
 
   po::options_description desc_general(sw::tr("General options"));
@@ -2212,7 +2215,7 @@ int main(int argc, char* argv[])
   po::positional_options_description positional_options;
   positional_options.add(arg_command.name, -1);
 
-  i18n_set_language("translations", "monero");
+  i18n_set_language("translations", "monero", lang);
 
   po::options_description desc_all;
   desc_all.add(desc_general).add(desc_params);