Issue 1283 - wrong usage of memset, fix sizeof, make proper initializing

src/plugin/PluginSystem.cpp

 #include "PluginStdAfx.h"
-
 #include "PluginSystem.h"
 #include "PluginClient.h"
+#include <array>
 
 std::wstring GetBrowserLanguage()
 {
   LANGID lcid = GetUserDefaultLangID();
-  wchar_t language[128];
-  memset(language, 0, sizeof(language));
-  wchar_t country[128];
-  memset(language, 0, sizeof(country));
-
   std::wstring lang;
-  int res = GetLocaleInfoW(lcid, LOCALE_SISO639LANGNAME, language, 127);
-  if (res == 0)
+  // we use `size() - 1` here to avoid additional calls to get the required size or to get the
+  // number of retrieved characters.
   {
-    DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_SYSINFO, PLUGIN_ERROR_SYSINFO_BROWSER_LANGUAGE, "System::GetBrowserLang - Failed");
-  }
-  else
-  {
-    lang += language;
+    std::array<wchar_t, 9> localeLanguage;
+    localeLanguage.fill(L'\0');
+    int res = GetLocaleInfoW(lcid, LOCALE_SISO639LANGNAME, localeLanguage.data(), localeLanguage.size() - 1);
+    if (res == 0)
+    {
+      DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_SYSINFO, PLUGIN_ERROR_SYSINFO_BROWSER_LANGUAGE, "System::GetBrowserLang - Failed");
+    }
+    else
+    {
+      lang += localeLanguage.data();
+    }
   }
   lang += L"-";
-  res = GetLocaleInfoW(lcid, LOCALE_SISO3166CTRYNAME, country, 127);
-  if (res == 0)
   {
-    DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_SYSINFO, PLUGIN_ERROR_SYSINFO_BROWSER_LANGUAGE, "System::GetBrowserLang - failed to retrieve country");
-  }
-  else
-  {
-    lang += country;
+    std::array<wchar_t, 9> localeCountry;
+    localeCountry.fill(L'\0');
+    int res = GetLocaleInfoW(lcid, LOCALE_SISO3166CTRYNAME, localeCountry.data(), localeCountry.size() - 1);
+    if (res == 0)
+    {
+      DEBUG_ERROR_LOG(::GetLastError(), PLUGIN_ERROR_SYSINFO, PLUGIN_ERROR_SYSINFO_BROWSER_LANGUAGE, "System::GetBrowserLang - failed to retrieve country");
+    }
+    else
+    {
+      lang += localeCountry.data();
+    }
   }
   return lang;
 }