bzr commit into mysql-5.1-bugteam branch (ramil:2699) Bug#37337

[Ramil Kalimullin]

#At file:///home/ram/mysql/mysql-5.1-bugteam/

 2699 Ramil Kalimullin	2008-08-15
      Fix for bug#37337: Function returns different results
      
      Problem: REGEXP in functions/PSs may return wrong results
      due to improper initialization.
      
      Fix: initialize required REGEXP params.
modified:
  mysql-test/r/func_regexp.result
  mysql-test/t/func_regexp.test
  sql/item_cmpfunc.cc

per-file messages:
  sql/item_cmpfunc.cc
    Fix for bug#37337: Function returns different results
    
    prev_regexp is used in the Item_func_regex::regcomp()
    to store previous regex and to avoid re-initialization 
    if given the same pattern.
    Shoud be deleted in the Item_func_regex::cleanup() where we
    clean up the regexp structure.
=== modified file 'mysql-test/r/func_regexp.result'
--- a/mysql-test/r/func_regexp.result	2008-02-12 19:09:16 +0000
+++ b/mysql-test/r/func_regexp.result	2008-08-15 05:53:25 +0000
@@ -115,3 +115,21 @@ SELECT 1 REGEXP NULL;
 1 REGEXP NULL
 NULL
 End of 5.0 tests
+CREATE TABLE t1(a INT, b CHAR(4));
+INSERT INTO t1 VALUES (1, '6.1'), (1, '7.0'), (1, '8.0');
+PREPARE stmt1 FROM "SELECT a FROM t1 WHERE a=1 AND '7.0' REGEXP b LIMIT 1";
+EXECUTE stmt1;
+a
+1
+EXECUTE stmt1;
+a
+1
+EXECUTE stmt1;
+a
+1
+EXECUTE stmt1;
+a
+1
+DEALLOCATE PREPARE stmt1;
+DROP TABLE t1;
+End of 5.1 tests

=== modified file 'mysql-test/t/func_regexp.test'
--- a/mysql-test/t/func_regexp.test	2007-11-06 12:03:58 +0000
+++ b/mysql-test/t/func_regexp.test	2008-08-15 05:53:25 +0000
@@ -65,3 +65,20 @@ drop table t1;
 SELECT 1 REGEXP NULL;
 
 --echo End of 5.0 tests
+
+
+#
+# Bug #37337: Function returns different results
+#
+CREATE TABLE t1(a INT, b CHAR(4));
+INSERT INTO t1 VALUES (1, '6.1'), (1, '7.0'), (1, '8.0');
+PREPARE stmt1 FROM "SELECT a FROM t1 WHERE a=1 AND '7.0' REGEXP b LIMIT 1";
+EXECUTE stmt1;
+EXECUTE stmt1;
+EXECUTE stmt1;
+EXECUTE stmt1;
+DEALLOCATE PREPARE stmt1;
+DROP TABLE t1;
+
+
+--echo End of 5.1 tests

=== modified file 'sql/item_cmpfunc.cc'
--- a/sql/item_cmpfunc.cc	2008-07-31 09:50:24 +0000
+++ b/sql/item_cmpfunc.cc	2008-08-15 05:53:25 +0000
@@ -4592,6 +4592,7 @@ void Item_func_regex::cleanup()
   {
     my_regfree(&preg);
     regex_compiled=0;
+    prev_regexp.length(0);
   }
   DBUG_VOID_RETURN;
 }