str(errno) as info attribute of LDAPError instance in case of LDAP_OP…

…T_ERROR_STRING returning null-string

CHANGES

@@ -7,6 +7,11 @@ Lib/
 * removed unused 2nd argument of ldap.schema.tokenizer.split_tokens()
 * fixed method calls in ReconnectLDAPObject (thanks to Philipp Hahn)
 
+Modules/
+* an empty info message is replaced with str(errno) if errno is non-zero
+  which gives more information e.g. in case of ldap.SERVER_DOWN
+  (thanks to Markus Klein)
+
 Tests/
 * re-factored t_ldap_schema_tokenizer.py
 
@@ -1348,4 +1353,4 @@ Released 2.0.0pre02 2002-02-01
 ----------------------------------------------------------------
 Released 1.10alpha3 2000-09-19
 
-$Id: CHANGES,v 1.413 2017/04/24 08:25:16 stroeder Exp $
+$Id: CHANGES,v 1.414 2017/04/24 18:32:50 stroeder Exp $

Modules/errors.c

@@ -2,10 +2,12 @@
  * errors that arise from ldap use
  * Most errors become their own exception
  * See http://www.python-ldap.org/ for details.
- * $Id: errors.c,v 1.27 2017/04/24 13:48:15 stroeder Exp $ */
+ * $Id: errors.c,v 1.28 2017/04/24 18:32:51 stroeder Exp $ */
 
 #include "common.h"
 #include "errors.h"
+#include <errno.h>
+#include <string.h>
 
 /* the base exception class */
 
@@ -96,13 +98,17 @@ LDAPerror( LDAP *l, char *msg )
         if (str)
       PyDict_SetItemString( info, "info", str );
         Py_XDECREF(str);
-    } else if (ldap_get_option(l, LDAP_OPT_ERROR_STRING, &error) >= 0
-      && error != NULL) {
-        if (*error != '\0') {
+    } else if (ldap_get_option(l, LDAP_OPT_ERROR_STRING, &error) >= 0) {
+        if (error != NULL && *error != '\0') {
             str = PyString_FromString(error);
             if (str)
                 PyDict_SetItemString( info, "info", str );
             Py_XDECREF(str);
+        } else if (errno != 0) {
+            str = PyString_FromString(strerror(errno));
+            if(str)
+                PyDict_SetItemString( info, "info", str);
+            Py_XDECREF(str);
         }
         ldap_memfree(error);
     }