[PATCH] Fix failure of mech plugins lacking gss_inquire_attrs_for_mech()

[David Woodhouse]

Since commit 030a4a03a ("Report inquire_attrs_For_mech mech failures")
the GSS-NTLMSSP plugin fails to work, because it doesn't provide a
gss_inquire_attrs_for_mech() method.

Sure, it can be fixed. But why do we need to break it? Isn't it
perfectly reasonable to assume that the answer is GSS_C_NO_OID_SET?

diff --git a/src/lib/gssapi/mechglue/g_mechattr.c b/src/lib/gssapi/mechglue/g_mechattr.c
index 08a6008..aa06319 100644
--- a/src/lib/gssapi/mechglue/g_mechattr.c
+++ b/src/lib/gssapi/mechglue/g_mechattr.c
@@ -181,14 +181,16 @@ gss_inquire_attrs_for_mech(
     mech = gssint_get_mechanism(selected_mech);
     if (mech == NULL)
         return GSS_S_BAD_MECH;
-    else if (mech->gss_inquire_attrs_for_mech == NULL)
-        return GSS_S_UNAVAILABLE;
-    public_mech = gssint_get_public_oid(selected_mech);
-    status = mech->gss_inquire_attrs_for_mech(minor, public_mech, mech_attrs,
-                                              known_mech_attrs);
-    if (GSS_ERROR(status)) {
-        map_error(minor, mech);
-        return status;
+
+    if (mech->gss_inquire_attrs_for_mech != NULL) {
+        public_mech = gssint_get_public_oid(selected_mech);
+        status = mech->gss_inquire_attrs_for_mech(minor, public_mech,
+                                                  mech_attrs,
+                                                  known_mech_attrs);
+        if (GSS_ERROR(status)) {
+            map_error(minor, mech);
+            return status;
+        }
     }
 
     if (known_mech_attrs != NULL && *known_mech_attrs == GSS_C_NO_OID_SET) {

-- 
David Woodhouse                            Open Source Technology Centre
David.Woodhouse at intel.com                              Intel Corporation

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