Fixed non thread-safe getLocalCharset() function (thanks to Bartek Szurgot).

src/platforms/posix/posixHandler.cpp

@@ -36,6 +36,11 @@
 #include <netdb.h>
 
 #include <string.h>
+#include <cassert>
+
+#if VMIME_HAVE_PTHREAD
+#	include <pthread.h>
+#endif // VMIME_HAVE_PTHREAD
 
 /*
 #ifdef _POSIX_PRIORITY_SCHEDULING
@@ -44,6 +49,43 @@
 */
 
 
+#if VMIME_HAVE_PTHREAD
+
+namespace
+{
+	// This construction ensures mutex will be initialized in compile-time
+	// and will be available any time in the runtime.
+	pthread_mutex_t g_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+	// Helper lock, to be exception safe all the time.
+	class PLockHelper
+	{
+	public:
+
+		PLockHelper()
+		{
+			if (pthread_mutex_lock(&g_mutex) != 0)
+				assert(!"unable to lock mutex - thread safety's void");
+		}
+
+		~PLockHelper()
+		{
+			if (pthread_mutex_unlock(&g_mutex) != 0)
+				assert(!"unable to unlock mutex - application's dead...");
+		}
+
+	private:
+
+		// Object cannot be copied
+		PLockHelper(const PLockHelper&);
+		const PLockHelper& operator=(const PLockHelper&);
+	};
+
+} // unnamed namespace
+
+#endif // VMIME_HAVE_PTHREAD
+
+
 namespace vmime {
 namespace platforms {
 namespace posix {
@@ -109,6 +151,8 @@ const vmime::datetime posixHandler::getCurrentLocalTime() const
 
 const vmime::charset posixHandler::getLocaleCharset() const
 {
+	const PLockHelper lock;
+
 	const char* prevLocale = ::setlocale(LC_ALL, "");
 	vmime::charset ch(::nl_langinfo(CODESET));
 	::setlocale(LC_ALL, prevLocale);