bk commit into 4.1 tree (ramil:1.2587) BUG#23254

[ramil]

Below is the list of changes that have just been committed into a local
4.1 repository of ram. When ram does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2006-10-13 19:05:54+05:00, ramil@stripped +3 -0
  Fix for bug #23254: COMPRESS(NULL) makes all futher COMPRESS() calls on same Item return
NULL
  
  We don't set null_value to 0 in the Item_func_compress::val_str() for 
  not-NULL results.

  mysql-test/r/func_compress.result@stripped, 2006-10-13 19:05:52+05:00, ramil@stripped +10
-0
    Fix for bug #23254: COMPRESS(NULL) makes all futher COMPRESS() calls on same Item
return NULL
      - test result.

  mysql-test/t/func_compress.test@stripped, 2006-10-13 19:05:52+05:00, ramil@stripped +13 -1
    Fix for bug #23254: COMPRESS(NULL) makes all futher COMPRESS() calls on same Item
return NULL
      - test case.

  sql/item_strfunc.cc@stripped, 2006-10-13 19:05:52+05:00, ramil@stripped +1 -0
    Fix for bug #23254: COMPRESS(NULL) makes all futher COMPRESS() calls on same Item
return NULL
      - set null_value.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	ramil
# Host:	myoffice.izhnet.ru
# Root:	/usr/home/ram/work/bug23254/my41-bug23254

--- 1.251/sql/item_strfunc.cc	2006-10-13 19:05:59 +05:00
+++ 1.252/sql/item_strfunc.cc	2006-10-13 19:05:59 +05:00
@@ -2838,6 +2838,7 @@ String *Item_func_compress::val_str(Stri
     null_value= 1;
     return 0;
   }
+  null_value= 0;
   if (res->is_empty()) return res;
 
   /*

--- 1.16/mysql-test/r/func_compress.result	2006-10-13 19:05:59 +05:00
+++ 1.17/mysql-test/r/func_compress.result	2006-10-13 19:05:59 +05:00
@@ -79,3 +79,13 @@ uncompress(a)	uncompressed_length(a)
 NULL	NULL
 a	1
 drop table t1;
+create table t1(a blob);
+insert into t1 values ('0'), (NULL), ('0');
+select compress(a), compress(a) from t1;
+select compress(a) is null from t1;
+compress(a) is null
+0
+1
+0
+drop table t1;
+End of 4.1 tests

--- 1.12/mysql-test/t/func_compress.test	2006-10-13 19:05:59 +05:00
+++ 1.13/mysql-test/t/func_compress.test	2006-10-13 19:05:59 +05:00
@@ -54,4 +54,16 @@ insert into t1 values(NULL), (compress('
 select uncompress(a), uncompressed_length(a) from t1;
 drop table t1;
 
-# End of 4.1 tests
+#
+# Bug #23254: problem with compress(NULL)
+#
+
+create table t1(a blob);
+insert into t1 values ('0'), (NULL), ('0');
+--disable_result_log
+select compress(a), compress(a) from t1;
+--enable_result_log
+select compress(a) is null from t1;
+drop table t1;
+
+--echo End of 4.1 tests