Changing field::field_name and Item::name to LEX_CSTRING

Benefits of this patch:
- Removed a lot of calls to strlen(), especially for field_string
- Strings generated by parser are now const strings, less chance of
  accidently changing a string
- Removed a lot of calls with LEX_STRING as parameter (changed to pointer)
- More uniform code
- Item::name_length was not kept up to date. Now fixed
- Several bugs found and fixed (Access to null pointers,
  access of freed memory, wrong arguments to printf like functions)
- Removed a lot of casts from (const char*) to (char*)

Changes:
- This caused some ABI changes
  - lex_string_set now uses LEX_CSTRING
  - Some fucntions are now taking const char* instead of char*
- Create_field::change and after changed to LEX_CSTRING
- handler::connect_string, comment and engine_name() changed to LEX_CSTRING
- Checked printf() related calls to find bugs. Found and fixed several
  errors in old code.
- A lot of changes from LEX_STRING to LEX_CSTRING, especially related to
  parsing and events.
- Some changes from LEX_STRING and LEX_STRING & to LEX_CSTRING*
- Some changes for char* to const char*
- Added printf argument checking for my_snprintf()
- Introduced null_clex_str, star_clex_string, temp_lex_str to simplify
  code
- Added item_empty_name and item_used_name to be able to distingush between
  items that was given an empty name and items that was not given a name
  This is used in sql_yacc.yy to know when to give an item a name.
- select table_name."*' is not anymore same as table_name.*
- removed not used function Item::rename()
- Added comparision of item->name_length before some calls to
  my_strcasecmp() to speed up comparison
- Moved Item_sp_variable::make_field() from item.h to item.cc
- Some minimal code changes to avoid copying to const char *
- Fixed wrong error message in wsrep_mysql_parse()
- Fixed wrong code in find_field_in_natural_join() where real_item() was
  set when it shouldn't
- ER_ERROR_ON_RENAME was used with extra arguments.
- Removed some (wrong) ER_OUTOFMEMORY, as alloc_root will already
  give the error.

TODO:
- Check possible unsafe casts in plugin/auth_examples/qa_auth_interface.c
- Change code to not modify LEX_CSTRING for database name
  (as part of lower_case_table_names)

1 files changed, 36 insertions, 35 deletions

diff --git a/sql/sql_view.cc b/sql/sql_view.cc
index 1d6fe38b66b..447d80b8b00 100644
--- a/sql/sql_view.cc
+++ b/sql/sql_view.cc
@@ -39,7 +39,7 @@
 
 #define MD5_BUFF_LENGTH 33
 
-const LEX_STRING view_type= { C_STRING_WITH_LEN("VIEW") };
+const LEX_CSTRING view_type= { STRING_WITH_LEN("VIEW") };
 
 static int mysql_register_view(THD *, TABLE_LIST *, enum_view_create_mode);
 
@@ -63,9 +63,9 @@ static void make_unique_view_field_name(THD *thd, Item *target,
                                         List<Item> &item_list,
                                         Item *last_element)
 {
-  char *name= (target->orig_name ?
-               target->orig_name :
-               target->name);
+  const char *name= (target->orig_name ?
+                     target->orig_name :
+                     target->name.str);
   size_t name_len;
   uint attempt;
   char buff[NAME_LEN+1];
@@ -85,7 +85,7 @@ static void make_unique_view_field_name(THD *thd, Item *target,
     {
       check= itc++;
       if (check != target &&
-          my_strcasecmp(system_charset_info, buff, check->name) == 0)
+          my_strcasecmp(system_charset_info, buff, check->name.str) == 0)
       {
         ok= FALSE;
         break;
@@ -96,7 +96,7 @@ static void make_unique_view_field_name(THD *thd, Item *target,
     itc.rewind();
   }
 
-  target->orig_name= target->name;
+  target->orig_name= target->name.str;
   target->set_name(thd, buff, name_len, system_charset_info);
 }
 
@@ -140,7 +140,7 @@ bool check_duplicate_names(THD *thd, List<Item> &item_list, bool gen_unique_view
     itc.rewind();
     while ((check= itc++) && check != item)
     {
-      if (my_strcasecmp(system_charset_info, item->name, check->name) == 0)
+      if (my_strcasecmp(system_charset_info, item->name.str, check->name.str) == 0)
       {
         if (!gen_unique_view_name)
           goto err;
@@ -178,10 +178,10 @@ void make_valid_column_names(THD *thd, List<Item> &item_list)
 
   for (uint column_no= 1; (item= it++); column_no++)
   {
-    if (!item->is_autogenerated_name || !check_column_name(item->name))
+    if (!item->is_autogenerated_name || !check_column_name(item->name.str))
       continue;
     name_len= my_snprintf(buff, NAME_LEN, "Name_exp_%u", column_no);
-    item->orig_name= item->name;
+    item->orig_name= item->name.str;
     item->set_name(thd, buff, name_len, system_charset_info);
   }
 
@@ -602,7 +602,7 @@ bool mysql_create_view(THD *thd, TABLE_LIST *views,
       {
         Item_field *fld= item->field_for_view_update();
         uint priv= (get_column_grant(thd, &view->grant, view->db,
-                                     view->table_name, item->name) &
+                                     view->table_name, item->name.str) &
                     VIEW_ANY_ACL);
 
         if (fld && !fld->field->table->s->tmp_table)
@@ -620,7 +620,7 @@ bool mysql_create_view(THD *thd, TABLE_LIST *views,
     {
       my_error(ER_COLUMNACCESS_DENIED_ERROR, MYF(0),
                "create view", thd->security_ctx->priv_user,
-               thd->security_ctx->priv_host, report_item->name,
+               thd->security_ctx->priv_host, report_item->name.str,
                view->table_name);
       res= TRUE;
       goto err;
@@ -711,11 +711,11 @@ err:
 }
 
 
-static void make_view_filename(LEX_STRING *dir, char *dir_buff,
+static void make_view_filename(LEX_CSTRING *dir, char *dir_buff,
                                size_t dir_buff_len,
-                               LEX_STRING *path, char *path_buff,
+                               LEX_CSTRING *path, char *path_buff,
                                size_t path_buff_len,
-                               LEX_STRING *file,
+                               LEX_CSTRING *file,
                                TABLE_LIST *view)
 {
   /* print file name */
@@ -741,37 +741,37 @@ static const int required_view_parameters= 15;
   parse()
 */
 static File_option view_parameters[]=
-{{{ C_STRING_WITH_LEN("query")},
+{{{ STRING_WITH_LEN("query")},
   my_offsetof(TABLE_LIST, select_stmt),
   FILE_OPTIONS_ESTRING},
- {{ C_STRING_WITH_LEN("md5")},
+ {{ STRING_WITH_LEN("md5")},
   my_offsetof(TABLE_LIST, md5),
   FILE_OPTIONS_STRING},
- {{ C_STRING_WITH_LEN("updatable")},
+ {{ STRING_WITH_LEN("updatable")},
   my_offsetof(TABLE_LIST, updatable_view),
   FILE_OPTIONS_ULONGLONG},
- {{ C_STRING_WITH_LEN("algorithm")},
+ {{ STRING_WITH_LEN("algorithm")},
   my_offsetof(TABLE_LIST, algorithm),
   FILE_OPTIONS_VIEW_ALGO},
- {{ C_STRING_WITH_LEN("definer_user")},
+ {{ STRING_WITH_LEN("definer_user")},
   my_offsetof(TABLE_LIST, definer.user),
   FILE_OPTIONS_STRING},
- {{ C_STRING_WITH_LEN("definer_host")},
+ {{ STRING_WITH_LEN("definer_host")},
   my_offsetof(TABLE_LIST, definer.host),
   FILE_OPTIONS_STRING},
- {{ C_STRING_WITH_LEN("suid")},
+ {{ STRING_WITH_LEN("suid")},
   my_offsetof(TABLE_LIST, view_suid),
   FILE_OPTIONS_ULONGLONG},
- {{ C_STRING_WITH_LEN("with_check_option")},
+ {{ STRING_WITH_LEN("with_check_option")},
   my_offsetof(TABLE_LIST, with_check),
   FILE_OPTIONS_ULONGLONG},
- {{ C_STRING_WITH_LEN("timestamp")},
+ {{ STRING_WITH_LEN("timestamp")},
   my_offsetof(TABLE_LIST, timestamp),
   FILE_OPTIONS_TIMESTAMP},
- {{ C_STRING_WITH_LEN("create-version")},
+ {{ STRING_WITH_LEN("create-version")},
   my_offsetof(TABLE_LIST, file_version),
   FILE_OPTIONS_ULONGLONG},
- {{ C_STRING_WITH_LEN("source")},
+ {{ STRING_WITH_LEN("source")},
   my_offsetof(TABLE_LIST, source),
   FILE_OPTIONS_ESTRING},
  {{(char*) STRING_WITH_LEN("client_cs_name")},
@@ -783,21 +783,21 @@ static File_option view_parameters[]=
  {{(char*) STRING_WITH_LEN("view_body_utf8")},
   my_offsetof(TABLE_LIST, view_body_utf8),
   FILE_OPTIONS_ESTRING},
- {{ C_STRING_WITH_LEN("mariadb-version")},
+ {{ STRING_WITH_LEN("mariadb-version")},
   my_offsetof(TABLE_LIST, mariadb_version),
   FILE_OPTIONS_ULONGLONG},
  {{NullS, 0},			0,
   FILE_OPTIONS_STRING}
 };
 
-static LEX_STRING view_file_type[]= {{(char*) STRING_WITH_LEN("VIEW") }};
+static LEX_CSTRING view_file_type[]= {{STRING_WITH_LEN("VIEW") }};
 
 
 int mariadb_fix_view(THD *thd, TABLE_LIST *view, bool wrong_checksum,
                      bool swap_alg)
 {
   char dir_buff[FN_REFLEN + 1], path_buff[FN_REFLEN + 1];
-  LEX_STRING dir, file, path;
+  LEX_CSTRING dir, file, path;
   DBUG_ENTER("mariadb_fix_view");
 
   if (!wrong_checksum && view->mariadb_version)
@@ -912,7 +912,7 @@ static int mysql_register_view(THD *thd, TABLE_LIST *view,
   char md5[MD5_BUFF_LENGTH];
   bool can_be_merged;
   char dir_buff[FN_REFLEN + 1], path_buff[FN_REFLEN + 1];
-  LEX_STRING dir, file, path;
+  LEX_CSTRING dir, file, path;
   int error= 0;
   DBUG_ENTER("mysql_register_view");
 
@@ -1014,7 +1014,7 @@ loop_out:
   /* check old .frm */
   {
     char path_buff[FN_REFLEN];
-    LEX_STRING path;
+    LEX_CSTRING path;
     File_parser *parser;
 
     path.str= path_buff;
@@ -1333,7 +1333,7 @@ bool mysql_make_view(THD *thd, TABLE_SHARE *share, TABLE_LIST *table,
 
   {
     char old_db_buf[SAFE_NAME_LEN+1];
-    LEX_STRING old_db= { old_db_buf, sizeof(old_db_buf) };
+    LEX_CSTRING old_db= { old_db_buf, sizeof(old_db_buf) };
     bool dbchanged;
     Parser_state parser_state;
     if (parser_state.init(thd, table->select_stmt.str,
@@ -1344,7 +1344,8 @@ bool mysql_make_view(THD *thd, TABLE_SHARE *share, TABLE_LIST *table,
       Use view db name as thread default database, in order to ensure
       that the view is parsed and prepared correctly.
     */
-    if ((result= mysql_opt_change_db(thd, &table->view_db, &old_db, 1,
+    if ((result= mysql_opt_change_db(thd, &table->view_db,
+                                     (LEX_STRING*) &old_db, 1,
                                      &dbchanged)))
       goto end;
 
@@ -1772,7 +1773,7 @@ bool mysql_drop_view(THD *thd, TABLE_LIST *views, enum_drop_mode drop_mode)
   char path[FN_REFLEN + 1];
   TABLE_LIST *view;
   String non_existant_views;
-  char *wrong_object_db= NULL, *wrong_object_name= NULL;
+  const char *wrong_object_db= NULL, *wrong_object_name= NULL;
   bool error= FALSE;
   bool some_views_deleted= FALSE;
   bool something_wrong= FALSE;
@@ -2137,7 +2138,7 @@ mysql_rename_view(THD *thd,
                   const char *new_name,
                   TABLE_LIST *view)
 {
-  LEX_STRING pathstr;
+  LEX_CSTRING pathstr;
   File_parser *parser;
   char path_buff[FN_REFLEN + 1];
   bool error= TRUE;
@@ -2153,7 +2154,7 @@ mysql_rename_view(THD *thd,
   {
     TABLE_LIST view_def;
     char dir_buff[FN_REFLEN + 1];
-    LEX_STRING dir, file;
+    LEX_CSTRING dir, file;
 
     /*
       To be PS-friendly we should either to restore state of