bk commit into 5.0 tree (gkodinov:1.2549) BUG#30788

[kgeorge]

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ChangeSet@stripped, 2007-10-26 12:40:58+03:00, gkodinov@stripped +5 -0
  Bug #30788: Inconsistent retrieval of char/varchar
   
  When using indexed search the server constructs a key image
  from the right arguments of the sargable conditions.
  String truncations during the creation of that image were
  not checked for and reported. Also error checking when
  using index for a subquery execution was not considering
  such errors as fatal and was continuing to search with the
  truncated string.
  Fixed the error processing to include and handle the truncation
  errors.

  mysql-test/r/key.result@stripped, 2007-10-26 12:40:55+03:00, gkodinov@stripped +14 -0
    Bug #30788: test case

  mysql-test/t/key.test@stripped, 2007-10-26 12:40:55+03:00, gkodinov@stripped +14 -0
    Bug #30788: test case

  sql/field.cc@stripped, 2007-10-26 12:40:55+03:00, gkodinov@stripped +1 -1
    Bug #30788: Check for data truncation errors (and
    return the appropriate error).
    The condition about not counting the cutted fields 
    is checked later.

  sql/item_subselect.cc@stripped, 2007-10-26 12:40:56+03:00, gkodinov@stripped +9 -3
    Bug #30788: Don't search the index when there are fatal 
    errors creating the key search image.

  sql/sql_select.h@stripped, 2007-10-26 12:40:56+03:00, gkodinov@stripped +1 -1
    Bug #30788: Treat truncation errors (2) as fatal key image creation
    errors.

diff -Nrup a/mysql-test/r/key.result b/mysql-test/r/key.result
--- a/mysql-test/r/key.result	2007-09-20 11:54:44 +03:00
+++ b/mysql-test/r/key.result	2007-10-26 12:40:55 +03:00
@@ -462,4 +462,18 @@ EXPLAIN SELECT MAX(a) FROM t1 FORCE INDE
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
 DROP TABLE t1;
+CREATE TABLE t1 (a CHAR(1), b VARCHAR(10));
+INSERT INTO t1 VALUES ('a', 'aa');
+INSERT INTO t1 VALUES ('a', 'aaa');
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+a	b
+CREATE INDEX I1 ON t1 (a);
+CREATE INDEX I2 ON t1 (b);
+EXPLAIN SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t1	index_subquery	I1	I1	2	func	2	Using index
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+a	b
+DROP TABLE t1;
 End of 5.0 tests.
diff -Nrup a/mysql-test/t/key.test b/mysql-test/t/key.test
--- a/mysql-test/t/key.test	2007-05-22 15:58:29 +03:00
+++ b/mysql-test/t/key.test	2007-10-26 12:40:55 +03:00
@@ -443,4 +443,18 @@ ALTER TABLE t1 DISABLE KEYS;
 EXPLAIN SELECT MAX(a) FROM t1 FORCE INDEX(a);
 DROP TABLE t1;
 
+#
+# Bug #30788: Inconsistent retrieval of char/varchar
+#
+
+CREATE TABLE t1 (a CHAR(1), b VARCHAR(10));
+INSERT INTO t1 VALUES ('a', 'aa');
+INSERT INTO t1 VALUES ('a', 'aaa');
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+CREATE INDEX I1 ON t1 (a);
+CREATE INDEX I2 ON t1 (b);
+EXPLAIN SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+DROP TABLE t1;
+
 --echo End of 5.0 tests.
diff -Nrup a/sql/field.cc b/sql/field.cc
--- a/sql/field.cc	2007-10-23 16:48:55 +03:00
+++ b/sql/field.cc	2007-10-26 12:40:55 +03:00
@@ -5907,7 +5907,7 @@ int Field_string::store(const char *from
     Check if we lost any important data (anything in a binary string,
     or any non-space in others).
   */
-  if ((from_end_pos < from + length) &&
table->in_use->count_cuted_fields)
+  if (from_end_pos < from + length)
   {
     if (test_if_important_data(field_charset, from_end_pos, from + length))
     {
diff -Nrup a/sql/item_subselect.cc b/sql/item_subselect.cc
--- a/sql/item_subselect.cc	2007-06-29 10:39:15 +03:00
+++ b/sql/item_subselect.cc	2007-10-26 12:40:56 +03:00
@@ -2173,6 +2173,7 @@ int subselect_indexsubquery_engine::exec
   DBUG_ENTER("subselect_indexsubquery_engine::exec");
   int error;
   bool null_finding= 0;
+  bool impossible_key;
   TABLE *table= tab->table;
 
   ((Item_in_subselect *) item)->value= 0;
@@ -2190,14 +2191,19 @@ int subselect_indexsubquery_engine::exec
   if (copy_ref_key())
     DBUG_RETURN(1);
 
+  impossible_key= (tab->ref.key_err & 1);
+
   if (null_keypart)
     DBUG_RETURN(scan_table());
 
   if (!table->file->inited)
     table->file->ha_index_init(tab->ref.key);
-  error= table->file->index_read(table->record[0],
-                                 tab->ref.key_buff,
-                                 tab->ref.key_length,HA_READ_KEY_EXACT);
+  if (!impossible_key)
+    error= table->file->index_read(table->record[0],
+                                   tab->ref.key_buff,
+                                   tab->ref.key_length,HA_READ_KEY_EXACT);
+  else
+    error= HA_ERR_KEY_NOT_FOUND;
   if (error &&
       error != HA_ERR_KEY_NOT_FOUND && error != HA_ERR_END_OF_FILE)
     error= report_error(table, error);
diff -Nrup a/sql/sql_select.h b/sql/sql_select.h
--- a/sql/sql_select.h	2007-10-10 16:26:00 +03:00
+++ b/sql/sql_select.h	2007-10-26 12:40:56 +03:00
@@ -615,7 +615,7 @@ public:
   {
     int res= item->save_in_field(to_field, 1);
     null_key= to_field->is_null() || item->null_value;
-    return (err != 0 || res > 2 ? STORE_KEY_FATAL : (store_key_result) res); 
+    return (err != 0 || res > 1 ? STORE_KEY_FATAL : (store_key_result) res); 
   }
 };