[rtems commit] libdl: Fix dlerror non-conformance

[Chris Johns]

Module:    rtems
Branch:    master
Commit:    e2f13430be3c74fade1319b97f6d21641152c732
Changeset: http://git.rtems.org/rtems/commit/?id=e2f13430be3c74fade1319b97f6d21641152c732

Author:    Chris Johns <chrisj at rtems.org>
Date:      Sat Feb  2 15:19:59 2019 +1100

libdl: Fix dlerror non-conformance

Closes #3298

---

 cpukit/libdl/dlfcn.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/cpukit/libdl/dlfcn.c b/cpukit/libdl/dlfcn.c
index 1d71645..b97078c 100644
--- a/cpukit/libdl/dlfcn.c
+++ b/cpukit/libdl/dlfcn.c
@@ -129,7 +129,10 @@ const char*
 dlerror (void)
 {
   static char msg[64];
-  rtems_rtl_get_error (msg, sizeof (msg));
+  int         eno;
+  eno = rtems_rtl_get_error (msg, sizeof (msg));
+  if (eno == 0)
+    return NULL;
   return msg;
 }