Bug 693451 - cannot use localized matching rules

https://bugzilla.redhat.com/show_bug.cgi?id=693451
Resolves: bug 693451
Bug Description: cannot use localized matching rules
Reviewed by: nkinder (Thanks!)
Branch: master
Fix Description: With the new matching rule code, the old method of
identifying a simple matching rule that can use a compare function is
not valid.  All of the collation plugin matching rules are ordering,
either ignore case or exact case.  So we need another way to tell if
the matching rule can use a simple compare function to generate index
keys.  The new function
int slapi_matchingrule_can_use_compare_fn(const char *mr_oid_or_name);
is used for this purpose.  It looks up the oid of the matching rule and
compares it to the oids used by the collation plugin.
Platforms tested: RHEL6 x86_64
Flag Day: no
Doc impact: no

ldap/servers/slapd/back-ldbm/ldbm_attr.c

@@ -293,6 +293,7 @@ attr_index_config(
 				/* check if this is a simple ordering specification
 				   for an attribute that has no ordering matching rule */
 				} else if (slapi_matchingrule_is_ordering(index_rules[j], attrsyntax_oid) &&
+						   slapi_matchingrule_can_use_compare_fn(index_rules[j]) &&
 						   !a->ai_sattr.a_mr_ord_plugin) { /* no ordering for this attribute */
 					need_compare_fn = 1; /* get compare func for this attr */
 					do_continue = 1; /* done with j - next j */

ldap/servers/slapd/match.c

@@ -333,3 +333,42 @@ int slapi_matchingrule_is_compat(const char *mr_oid_or_name, const char *syntax_
 
     return 0;
 }
+
+/* the matching rules defined in the collation plugin
+   all start with this OID
+*/
+#define COLLATION_BASE_OID "2.16.840.1.113730.3.3.2."
+#define COLLATION_BASE_OID_LEN 24
+
+/*
+  See if a matching rule for this name or OID
+  can use a simple compare function for generating index entries
+*/
+int slapi_matchingrule_can_use_compare_fn(const char *mr_oid_or_name)
+{
+    struct matchingRuleList *mrl=NULL;
+    int found = 0;
+
+    for (mrl = g_get_global_mrl(); mrl != NULL; mrl = mrl->mrl_next) {
+        if (mrl->mr_entry->mr_name && !strcasecmp(mr_oid_or_name, mrl->mr_entry->mr_name)) {
+            found = 1;
+            break;
+        }
+        if (mrl->mr_entry->mr_oid && !strcmp(mr_oid_or_name, mrl->mr_entry->mr_oid)) {
+            found = 1;
+            break;
+        }
+    }
+
+    if (!found) {
+        return 0;
+    }
+
+    if (!strncmp(mrl->mr_entry->mr_oid, COLLATION_BASE_OID, COLLATION_BASE_OID_LEN)) {
+        /* this OID is provided by the collation plugin so we can't just
+           use a simple compare function to generate index keys */
+        return 0;
+    }
+
+    return 1;
+}

ldap/servers/slapd/slapi-plugin.h

@@ -4659,6 +4659,18 @@ int slapi_matchingrule_is_ordering(const char *oid_or_name, const char *syntax_o
  */
 int slapi_matchingrule_is_compat(const char *mr_oid_or_name, const char *syntax_oid);
 
+/**
+ * In certain cases, we can just use a simple compare function to
+ * generate index keys.  The compare function is usually provided
+ * by the syntax plugin.  If this is the case, we can skip generating
+ * an indexer in the index config code.
+ * 
+ * \param mr_name_or_oid Name or OID of a matching rule
+ * \return \c TRUE if the matching rule can use a simple compare function
+ * \return \c FALSE otherwise 
+ */
+int slapi_matchingrule_can_use_compare_fn(const char *mr_oid_or_name);
+
 /*
  * access control
  */