merge mysql-5.5->mysql-5.5-bugteam

1 files changed, 16 insertions, 3 deletions

diff --git a/sql/item.cc b/sql/item.cc
index 5645a1bee1c..b1e453121bd 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -7503,9 +7503,19 @@ void Item_cache_datetime::store(Item *item, longlong val_arg)
 }
 
 
+void Item_cache_datetime::store(Item *item)
+{
+  Item_cache::store(item);
+  str_value_cached= FALSE;
+}
+
 String *Item_cache_datetime::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
+
+  if ((value_cached || str_value_cached) && null_value)
+    return NULL;
+
   if (!str_value_cached)
   {
     /*
@@ -7519,6 +7529,8 @@ String *Item_cache_datetime::val_str(String *str)
     if (value_cached)
     {
       MYSQL_TIME ltime;
+      /* Return NULL in case of OOM/conversion error. */
+      null_value= TRUE;
       if (str_value.alloc(MAX_DATE_STRING_REP_LENGTH))
         return NULL;
       if (cached_field_type == MYSQL_TYPE_TIME)
@@ -7541,13 +7553,14 @@ String *Item_cache_datetime::val_str(String *str)
       {
         int was_cut;
         longlong res;
-        res= number_to_datetime(val_int(), &ltime, TIME_FUZZY_DATE, &was_cut);
+        res= number_to_datetime(int_value, &ltime, TIME_FUZZY_DATE, &was_cut);
         if (res == -1)
           return NULL;
       }
       str_value.length(my_TIME_to_str(&ltime,
                                       const_cast<char*>(str_value.ptr())));
       str_value_cached= TRUE;
+      null_value= FALSE;
     }
     else if (!cache_value())
       return NULL;
@@ -7568,7 +7581,7 @@ my_decimal *Item_cache_datetime::val_decimal(my_decimal *decimal_val)
 double Item_cache_datetime::val_real()
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached && !cache_value_int())
+  if ((!value_cached && !cache_value_int()) || null_value)
     return 0.0;
   return (double) int_value;
 }
@@ -7576,7 +7589,7 @@ double Item_cache_datetime::val_real()
 longlong Item_cache_datetime::val_int()
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached && !cache_value_int())
+  if ((!value_cached && !cache_value_int()) || null_value)
     return 0;
   return int_value;
 }