This commit fixes

  - errno handling in wsp::env::append() method, where error could be returned by mistake
  - return code of sst_prepare_other() when pthread_create() fails - it was returning positive error code which by convention is treated as success.

sql/wsrep_sst.cc

-/* Copyright 2008-2012 Codership Oy <http://www.codership.com>
+/* Copyright 2008-2015 Codership Oy <http://www.codership.com>
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -485,7 +485,7 @@ static ssize_t sst_prepare_other (const char*  method,
   {
     WSREP_ERROR("sst_prepare_other(): pthread_create() failed: %d (%s)",
                 ret, strerror(ret));
-    return ret;
+    return -ret;
   }
   mysql_cond_wait (&arg.cond, &arg.lock);
 

sql/wsrep_utils.cc

-/* Copyright 2010 Codership Oy <http://www.codership.com>
+/* Copyright 2010-2015 Codership Oy <http://www.codership.com>
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -165,10 +165,9 @@ env::append(const char* val)
             ++len_;
             env_[len_] = NULL;
         }
+        else errno_ = errno;
     }
-
-    /* if either realloc() or strdup() failed, errno had been set */
-    errno_ = errno;
+    else errno_ = errno;
 
     return errno_;
 }

sql/wsrep_utils.h

-/* Copyright (C) 2013 Codership Oy <info@codership.com>
+/* Copyright (C) 2013-2015 Codership Oy <info@codership.com>
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by