Added a proper check for acceptable mutually recursive CTE.

mysql-test/r/cte_recursive.result

@@ -4,6 +4,21 @@ insert into t1 values
 insert into t1 values
 (3,'eee'), (7,'bb'), (1,'fff'), (4,'ggg');
 with recursive
+t as 
+(
+select * from t1 where t1.b >= 'c'
+  union
+select * from r
+),
+r as
+(
+select * from t
+union
+select t1.* from t1,r where r.a+1 = t1.a
+)
+select * from r;
+ERROR HY000: Unacceptable mutual recursion with anchored table 't'
+with recursive
 a1(a,b) as
 (select * from t1 where t1.a>3
 union
@@ -19,7 +34,7 @@ c1(a,b) as
 union
 select * from b1 where b1.b > 'auu')
 select * from c1;
-ERROR HY000: No anchors for recursive WITH element 'b1'
+ERROR HY000: Unacceptable mutual recursion with anchored table 'a1'
 drop table t1;
 # WITH RECURSIVE vs just WITH
 create table t1 (a int);

mysql-test/suite/sys_vars/r/sysvars_server_embedded.result

@@ -1996,7 +1996,7 @@ NUMERIC_MAX_VALUE	4294967295
 NUMERIC_BLOCK_SIZE	1
 ENUM_VALUE_LIST	NULL
 READ_ONLY	NO
-+COMMAND_LINE_ARGUMENT	OPTIONAL
+COMMAND_LINE_ARGUMENT	OPTIONAL
 VARIABLE_NAME	MAX_SEEKS_FOR_KEY
 SESSION_VALUE	4294967295
 GLOBAL_VALUE	4294967295

mysql-test/t/cte_recursive.test

@@ -4,7 +4,24 @@ insert into t1 values
 insert into t1 values
 (3,'eee'), (7,'bb'), (1,'fff'), (4,'ggg');
 
---ERROR ER_RECURSIVE_WITHOUT_ANCHORS
+--ERROR ER_UNACCEPTABLE_MUTUAL_RECURSION
+with recursive
+t as 
+(
+  select * from t1 where t1.b >= 'c'
+  union
+  select * from r
+),
+r as
+(
+  select * from t
+  union
+  select t1.* from t1,r where r.a+1 = t1.a
+)
+select * from r;
+
+
+--ERROR ER_UNACCEPTABLE_MUTUAL_RECURSION
 with recursive
 a1(a,b) as
 (select * from t1 where t1.a>3

sql/share/errmsg-utf8.txt

@@ -7154,6 +7154,8 @@ ER_DUP_QUERY_NAME
         eng "Duplicate query name in WITH clause"
 ER_RECURSIVE_WITHOUT_ANCHORS
         eng "No anchors for recursive WITH element '%s'"
+ER_UNACCEPTABLE_MUTUAL_RECURSION
+        eng "Unacceptable mutual recursion with anchored table '%s'"
 ER_REF_TO_RECURSIVE_WITH_TABLE_IN_DERIVED
         eng "Reference to recursive WITH table '%s' in materiazed derived"
 ER_NOT_STANDARDS_COMPLIANT_RECURSIVE

sql/sql_cte.cc

@@ -292,43 +292,50 @@ bool With_clause::check_anchors()
        with_elem != NULL;
        with_elem= with_elem->next_elem)
   {
-    if (!with_elem->is_recursive || with_elem->with_anchor)
+    if (!with_elem->is_recursive)
       continue;
-
-    table_map anchored= 0;
-    for (With_element *elem= with_elem;
-	 elem != NULL;
-	 elem= elem->next_elem)
-    {
-      if (elem->mutually_recursive && elem->with_anchor)
-	  anchored |= elem->get_elem_map();
-    }
-    table_map non_anchored= with_elem->mutually_recursive & ~anchored;
-    with_elem->work_dep_map= non_anchored & with_elem->base_dep_map;
-  }
-
-  /*Building transitive clousure on work_dep_map*/
-  for (With_element *with_elem= first_elem;
-       with_elem != NULL;
-       with_elem= with_elem->next_elem)
-  {
-    table_map with_elem_map= with_elem->get_elem_map();
-    for (With_element *elem= first_elem; elem != NULL; elem= elem->next_elem)
+    
+    if (!with_elem->with_anchor)
     {
-      if (elem->work_dep_map & with_elem_map)
-	elem->work_dep_map|= with_elem->work_dep_map;
+      With_element *elem= with_elem;
+      while ((elem= elem->get_next_mutually_recursive()) != with_elem)
+      {
+        if (elem->with_anchor)
+          break;
+      }
+      if (elem == with_elem)
+      {
+        my_error(ER_RECURSIVE_WITHOUT_ANCHORS, MYF(0),
+        with_elem->query_name->str);
+        return true;
+      }
     }
-  }
-
-  for (With_element *with_elem= first_elem;
-       with_elem != NULL;
-       with_elem= with_elem->next_elem)
-  {
-    if (with_elem->work_dep_map & with_elem->get_elem_map())
+    else
     {
-      my_error(ER_RECURSIVE_WITHOUT_ANCHORS, MYF(0),
-      with_elem->query_name->str);
-      return true;
+      With_element *elem= with_elem;
+      while ((elem= elem->get_next_mutually_recursive()) != with_elem)
+	elem->work_dep_map= elem->base_dep_map & elem->mutually_recursive;
+      elem= with_elem;
+      while ((elem= elem->get_next_mutually_recursive()) != with_elem)
+      {
+        table_map elem_map= elem->get_elem_map();
+        With_element *el= with_elem;
+        while ((el= el->get_next_mutually_recursive()) != with_elem)
+	{
+          if (el->work_dep_map & elem_map)
+	    el->work_dep_map|= elem->work_dep_map;          
+        }
+      }
+      elem= with_elem;
+      while ((elem= elem->get_next_mutually_recursive()) != with_elem)
+      {
+        if (elem->work_dep_map & elem->get_elem_map())
+	{
+          my_error(ER_UNACCEPTABLE_MUTUAL_RECURSION, MYF(0),
+          with_elem->query_name->str);
+          return true;
+	}
+      }
     }
   }