Merge pull request #223 from oold/patch-2

Don't pass buffer as format string and free buffer

Author: bombela

backward.hpp

@@ -3639,13 +3639,14 @@ template <> class TraceResolverImpl<system_tag::windows_tag>
       char* lpMsgBuf;
       DWORD dw = GetLastError();
 
-      FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
-                        FORMAT_MESSAGE_FROM_SYSTEM |
-                        FORMAT_MESSAGE_IGNORE_INSERTS,
-                    NULL, dw, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-                    (char*)&lpMsgBuf, 0, NULL);
-
-      printf(lpMsgBuf);
+      if (FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+                             FORMAT_MESSAGE_FROM_SYSTEM |
+                             FORMAT_MESSAGE_IGNORE_INSERTS,
+                         NULL, dw, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                         (char*)&lpMsgBuf, 0, NULL)) {
+        std::fprintf(stderr, "%s\n", lpMsgBuf);
+        LocalFree(lpMsgBuf);
+      }
 
       // abort();
     }