Post review fixes for "SQL Syntax for Prepared Statements".

mysql-test/r/ps.result:
  Better error message
mysys/my_error.c:
  Comments added
sql/item.cc:
  Moved a chunk of code from sql_prepare.cc to Item_param::set_from_user_var
sql/item.h:
  Moved a chunk of code from sql_prepare.cc to Item_param::set_from_user_var
sql/item_func.cc:
  Code cleanup
sql/mysql_priv.h:
  Code cleanup
sql/sql_class.cc:
  Code cleanup
sql/sql_parse.cc:
  use user_var_entry::val_str in PREPARE stmt FROM @var.
sql/sql_prepare.cc:
  Post-review fixes and code cleanup.
sql/sql_yacc.yy:
  Coding style fixes

1 files changed, 66 insertions, 4 deletions

diff --git a/sql/item.cc b/sql/item.cc
index ad209817d8a..cabae46ed71 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -255,7 +255,7 @@ bool Item::get_time(TIME *ltime)
   return 0;
 }
 
-CHARSET_INFO * Item::default_charset() 
+CHARSET_INFO *Item::default_charset()
 {
   return current_thd->variables.collation_connection;
 }
@@ -736,6 +736,70 @@ bool Item_param::set_longdata(const char *str, ulong length)
 
 
 /*
+  Set parameter value from user variable value.
+
+  SYNOPSIS
+   set_from_user_var
+     thd   Current thread
+     entry User variable structure (NULL means use NULL value)
+
+  RETURN
+    0 OK
+    1 Out of memort
+*/
+
+bool Item_param::set_from_user_var(THD *thd, const user_var_entry *entry)
+{
+  DBUG_ENTER("Item_param::set_from_user_var");
+  if (entry && entry->value)
+  {
+    item_result_type= entry->type;
+    switch (entry->type)
+    {
+      case REAL_RESULT:
+        set_double(*(double*)entry->value);
+        break;
+      case INT_RESULT:
+        set_int(*(longlong*)entry->value, 21);
+        break;
+      case STRING_RESULT:
+        {
+          CHARSET_INFO *fromcs= entry->collation.collation;
+          CHARSET_INFO *tocs= thd->variables.collation_connection;
+          uint32 dummy_offset;
+
+          value.cs_info.character_set_client= fromcs;
+          /*
+            Setup source and destination character sets so that they
+            are different only if conversion is necessary: this will
+            make later checks easier.
+          */
+          value.cs_info.final_character_set_of_str_value=
+            String::needs_conversion(0, fromcs, tocs, &dummy_offset) ?
+            tocs : fromcs;
+          /*
+            Exact value of max_length is not known unless data is converted to
+            charset of connection, so we have to set it later.
+          */
+          item_type= Item::STRING_ITEM;
+          item_result_type= STRING_RESULT;
+
+          if (set_str((const char *)entry->value, entry->length))
+            DBUG_RETURN(1);
+        }
+        break;
+      default:
+        DBUG_ASSERT(0);
+        set_null();
+    }
+  }
+  else
+    set_null();
+
+  DBUG_RETURN(0);
+}
+
+/*
     Resets parameter after execution.
   
   SYNOPSIS
@@ -767,8 +831,6 @@ void Item_param::reset()
 
 int Item_param::save_in_field(Field *field, bool no_conversions)
 {
-  DBUG_ASSERT(current_thd->command == COM_EXECUTE);
-
   field->set_notnull();
 
   switch (state) {
@@ -1666,7 +1728,7 @@ bool Item::send(Protocol *protocol, String *buffer)
   }
   case MYSQL_TYPE_TINY:
   {
-    longlong nr;  
+    longlong nr;
     nr= val_int();
     if (!null_value)
       result= protocol->store_tiny(nr);