Don't generate message in send_kill_message() if wrong data. (Caused core dump...

Don't generate message in send_kill_message() if wrong data. (Caused core dump for wrong data in ALTER TABLE on some system)


sql/item_timefunc.cc:
  Removed warning reported by valgrind
sql/sql_error.cc:
  Fixed comment
sql/sql_table.cc:
  Fixed comment

sql/item_timefunc.cc

@@ -2199,7 +2199,7 @@ String *Item_char_typecast::val_str(String *str)
     push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
                         ER_TRUNCATED_WRONG_VALUE,
                         ER(ER_TRUNCATED_WRONG_VALUE), char_type,
-                        res->c_ptr());
+                        res->c_ptr_safe());
     res->length((uint) length);
   }
   null_value= 0;

sql/sql_class.h

@@ -1410,6 +1410,7 @@ class THD :public ilink,
   inline void send_kill_message() const
   {
     int err= killed_errno();
+    if (err)
       my_message(err, ER(err), MYF(0));
   }
   /* return TRUE if we will abort query if we make a warning now */

sql/sql_error.cc

@@ -133,7 +133,7 @@ MYSQL_ERROR *push_warning(THD *thd, MYSQL_ERROR::enum_warning_level level,
 
     thd->spcont= spcont;
     thd->no_warnings_for_error= no_warnings_for_error;
-    /* Store error in error list (as my_message() didn't do it in this case */
+    /* Store error in error list (as my_message() didn't do it) */
     level= MYSQL_ERROR::WARN_LEVEL_ERROR;
   }
 

sql/sql_table.cc

@@ -3740,9 +3740,11 @@ copy_data_between_tables(TABLE *from,TABLE *to,
       goto err;
   };
 
-  /* Handler must be told explicitly to retrieve all columns, because
+  /*
+    Handler must be told explicitly to retrieve all columns, because
     this function does not set field->query_id in the columns to the
-     current query id */
+    current query id
+  */
   from->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
   init_read_record(&info, thd, from, (SQL_SELECT *) 0, 1,1);
   if (ignore ||