Merge gbichot@bk-internal.mysql.com:/home/bk/mysql-4.1

into mysql.com:/home/mysql_src/mysql-4.1-clean

myisam/mi_open.c

@@ -142,7 +142,7 @@ MI_INFO *mi_open(const char *name, int mode, uint open_flags)
       goto err;
     }
     /* Don't call realpath() if the name can't be a link */
-    if (strcmp(name_buff, org_name)  ||
+    if (!strcmp(name_buff, org_name) ||
         my_readlink(index_name, org_name, MYF(0)) == -1)
       (void) strmov(index_name, org_name);
     (void) fn_format(data_name,org_name,"",MI_NAME_DEXT,2+4+16);

mysql-test/r/ctype_utf8.result

@@ -849,3 +849,15 @@ utf8_bin	6109
 utf8_bin	61
 utf8_bin	6120
 drop table t1;
+CREATE TABLE t1 (
+user varchar(255) NOT NULL default ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1;
+INSERT INTO t1 VALUES ('one'),('two');
+SELECT CHARSET('a');
+CHARSET('a')
+utf8
+SELECT user, CONCAT('<', user, '>') AS c FROM t1;
+user	c
+one	<one>
+two	<two>
+DROP TABLE t1;

mysql-test/t/ctype_utf8.test

@@ -681,3 +681,15 @@ SET collation_connection='utf8_general_ci';
 -- source include/ctype_filesort.inc
 SET collation_connection='utf8_bin';
 -- source include/ctype_filesort.inc
+
+#
+# Bug #7874 CONCAT() gives wrong results mixing
+# latin1 field and utf8 string literals
+#
+CREATE TABLE t1 (
+	user varchar(255) NOT NULL default ''
+) ENGINE=MyISAM DEFAULT CHARSET=latin1;
+INSERT INTO t1 VALUES ('one'),('two');
+SELECT CHARSET('a');
+SELECT user, CONCAT('<', user, '>') AS c FROM t1;
+DROP TABLE t1;

mysys/my_symlink.c

@@ -26,9 +26,11 @@
 /*
   Reads the content of a symbolic link
   If the file is not a symbolic link, return the original file name in to.
-  Returns: 0 if table was a symlink,
-           1 if table was a normal file
-	   -1 on error.
+
+  RETURN
+    0  If filename was a symlink,    (to will be set to value of symlink)
+    1  If filename was a normal file (to will be set to filename)
+   -1  on error.
 */
 
 int my_readlink(char *to, const char *filename, myf MyFlags)
@@ -58,6 +60,7 @@ int my_readlink(char *to, const char *filename, myf MyFlags)
   }
   else
     to[length]=0;
+  DBUG_PRINT("exit" ,("result: %d", result));
   DBUG_RETURN(result);
 #endif /* HAVE_READLINK */
 }

sql/filesort.cc

@@ -809,7 +809,10 @@ int merge_many_buff(SORTPARAM *param, uchar *sort_buffer,
   }
   close_cached_file(to_file);			// This holds old result
   if (to_file == t_file)
+  {
     *t_file=t_file2;				// Copy result file
+    setup_io_cache(t_file);
+  }
 
   DBUG_RETURN(*maxbuffer >= MERGEBUFF2);	/* Return 1 if interrupted */
 } /* merge_many_buff */

sql/item_strfunc.cc

@@ -275,7 +275,8 @@ String *Item_func_concat::val_str(String *str)
 			    current_thd->variables.max_allowed_packet);
 	goto null;
       }
-      if (res->alloced_length() >= res->length()+res2->length())
+      if (!args[0]->const_item() && 
+          res->alloced_length() >= res->length()+res2->length())
       {						// Use old buffer
 	res->append(*res2);
       }

sql/sql_yacc.yy

@@ -4008,7 +4008,8 @@ insert:
 	{
 	  LEX *lex= Lex;
 	  lex->sql_command= SQLCOM_INSERT;
-	  lex->duplicates= DUP_ERROR; 
+	  lex->duplicates= DUP_ERROR;
+          mysql_init_select(lex);
 	  /* for subselects */
           lex->lock_option= (using_update_log) ? TL_READ_NO_INSERT : TL_READ;
 	  lex->select_lex.resolve_mode= SELECT_LEX::INSERT_MODE;
@@ -4028,6 +4029,7 @@ replace:
 	  LEX *lex=Lex;
 	  lex->sql_command = SQLCOM_REPLACE;
 	  lex->duplicates= DUP_REPLACE;
+          mysql_init_select(lex);
 	  lex->select_lex.resolve_mode= SELECT_LEX::INSERT_MODE;
 	}
 	replace_lock_option insert2
@@ -4229,6 +4231,7 @@ delete:
 	{
 	  LEX *lex= Lex;
 	  lex->sql_command= SQLCOM_DELETE;
+          mysql_init_select(lex);
 	  lex->lock_option= lex->thd->update_lock_default;
 	  lex->ignore= 0;
 	  lex->select_lex.init_order();
@@ -5321,6 +5324,7 @@ set:
 	{
 	  LEX *lex=Lex;
 	  lex->sql_command= SQLCOM_SET_OPTION;
+          mysql_init_select(lex);
 	  lex->option_type=OPT_SESSION;
 	  lex->var_list.empty();
           lex->one_shot_set= 0;