Fixed all reported bugs for dynamic columns.

Bugs fixed:
- Added automatic detection of unsigned arguments to COLUMN_CREATE()
- If string length is not know for COLUMN_GET() use MAX_DYNAMIC_COLUMN_LENGTH instead of MAX_FIELD_BLOBLENGTH
- null_value flag was not propery reset for COLUMN_LIST() and COLUMN_CREATE() which could lead to crashes later:
- lp:778905 Assertion `value->year <= 9999' failed in dynamic_column_date_store
- lp:778912 Assertion `field_pos < field_count' failed in Protocol_text::store in maria-5.3-mwl34

include/ma_dyncol.h:
  Added define for max dynamic column length.
mysql-test/r/cast.result:
  Added test of cast big unsigned int to signed (this test case was missing)
mysql-test/r/dyncol.result:
  Added tests from reported bugs
  Added testing of automatic store of signed/unsigned integers
mysql-test/t/cast.test:
  Added test of cast big unsigned int to signed (this test case was missing)
mysql-test/t/dyncol.test:
  Added tests from reported bugs
  Added testing of automatic store of signed/unsigned integers
sql/item.cc:
  Added assert to catch cases where null_value is not set properly
sql/item_strfunc.cc:
  Added automatic detection of unsigned arguments to COLUMN_CREATE()
  COLUMN_GET() returned wrong value for illegal strings which lead to assert later
  null_value flag was not propery reset for COLUMN_LIST() and COLUMN_CREATE() which could lead to crashes later.
sql/item_strfunc.h:
  If string length is not know for COLUMN_GET() use MAX_DYNAMIC_COLUMN_LENGTH

1 files changed, 13 insertions, 2 deletions

diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 1471fcab001..4170b356fb7 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -3511,7 +3511,7 @@ void Item_func_dyncol_create::prepare_arguments()
       case MYSQL_TYPE_INT24:
       case MYSQL_TYPE_YEAR:
       case MYSQL_TYPE_BIT:
-        type= DYN_COL_INT;
+        type= args[valpos]->unsigned_flag ? DYN_COL_UINT : DYN_COL_INT;
         break;
       case MYSQL_TYPE_FLOAT:
       case MYSQL_TYPE_DOUBLE:
@@ -3653,6 +3653,7 @@ String *Item_func_dyncol_create::val_str(String *str)
     str_value.reassociate(ptr, (uint32) length, (uint32) alloc_length,
                           &my_charset_bin);
     res= &str_value;
+    null_value= FALSE;
   }
 
   /* cleanup */
@@ -3756,6 +3757,7 @@ String *Item_func_dyncol_add::val_str(String *str)
     dynamic_column_reassociate(&col, &ptr, &length, &alloc_length);
     str->reassociate(ptr, (uint32) length, (uint32) alloc_length,
                      &my_charset_bin);
+    null_value= FALSE;
   }
 
   /* cleanup */
@@ -3781,6 +3783,14 @@ void Item_func_dyncol_add::print(String *str,
   str->append(')');
 }
 
+
+/**
+  Get value for a column stored in a dynamic column
+
+  @notes
+  This function ensures that null_value is set correctly
+*/
+
 bool Item_dyncol_get::get_dyn_value(DYNAMIC_COLUMN_VALUE *val, String *tmp)
 {
   DYNAMIC_COLUMN dyn_str;
@@ -4104,7 +4114,7 @@ bool Item_dyncol_get::get_date(MYSQL_TIME *ltime, uint fuzzy_date)
   bool signed_value= 0;
 
   if (get_dyn_value(&val, &tmp))
-    return 0;
+    return 1;                                   // Error
 
   switch (val.type) {
   case DYN_COL_NULL:
@@ -4208,6 +4218,7 @@ String *Item_func_dyncol_list::val_str(String *str)
       str->qs_append(',');
   }
 
+  null_value= FALSE;
   delete_dynamic(&arr);
   return str;