csv_util: Check for a valid creation time.

diff --git a/gpsbabel/csv_util.c b/gpsbabel/csv_util.c
index 77a50024ca94d874fbb373d08ea3f1d664b7c4f5..e8a55a8cab3fb4b7a41c8dbc49c11d0c0e96e571 100644 (file)
--- a/gpsbabel/csv_util.c
+++ b/gpsbabel/csv_util.c
@@ -779,7 +779,11 @@ yyyymmdd_to_time(const char *s)
        tm.tm_mon = t % 100 - 1;
        t = t / 100;
        tm.tm_year = t - 1900;
-       return mktime(&tm);
+       
+       if (mkgmtime(&tm) > 0)
+               return mktime(&tm);
+       else
+               return 0;
 }