Bug 829518 - Enclose InternetQueryOptionW in __try...__except to suppress crash. r=mcmanus

toolkit/system/windowsproxy/nsWindowsSystemProxySettings.cpp

@@ -91,8 +91,12 @@ static nsresult ReadInternetOption(uint32_t aOption, uint32_t& aFlags,
         }
         options[0].dwOption = INTERNET_PER_CONN_FLAGS;
         size = sizeof(INTERNET_PER_CONN_OPTION_LISTW);
-        if (!InternetQueryOptionW(NULL, INTERNET_OPTION_PER_CONNECTION_OPTION,
-                                  &list, &size)) {
+        __try {
+            if (!InternetQueryOptionW(NULL, INTERNET_OPTION_PER_CONNECTION_OPTION,
+                                      &list, &size)) {
+                return NS_ERROR_FAILURE;
+            }
+        } __except (EXCEPTION_EXECUTE_HANDLER) {
             return NS_ERROR_FAILURE;
         }
     }