Fix value returned from SELECT of unsigned long system

variables. (Bug #10351)

mysql-test/r/variables.result

@@ -525,3 +525,15 @@ set @@warning_count=1;
 ERROR HY000: Variable 'warning_count' is a read only variable
 set @@global.error_count=1;
 ERROR HY000: Variable 'error_count' is a read only variable
+set @@max_heap_table_size= 4294967296;
+select @@max_heap_table_size;
+@@max_heap_table_size
+4294967296
+set global max_heap_table_size= 4294967296;
+select @@max_heap_table_size;
+@@max_heap_table_size
+4294967296
+set @@max_heap_table_size= 4294967296;
+select @@max_heap_table_size;
+@@max_heap_table_size
+4294967296

mysql-test/t/variables.test

@@ -406,3 +406,13 @@ drop table t1;
 set @@warning_count=1;
 --error 1238
 set @@global.error_count=1;
+
+#
+# Bug #10351: Setting max_heap_table_size to 4G fails
+#
+set @@max_heap_table_size= 4294967296;
+select @@max_heap_table_size;
+set global max_heap_table_size= 4294967296;
+select @@max_heap_table_size;
+set @@max_heap_table_size= 4294967296;
+select @@max_heap_table_size;

sql/item.h

@@ -1142,6 +1142,7 @@ class Item_uint :public Item_int
 public:
   Item_uint(const char *str_arg, uint length);
   Item_uint(uint32 i) :Item_int((ulonglong) i, 10) {}
+  Item_uint(ulong i) :Item_int((ulonglong) i, 10) {}
   Item_uint(const char *str_arg, longlong i, uint length);
   double val_real()
     { DBUG_ASSERT(fixed == 1); return ulonglong2double((ulonglong)value); }

sql/mysqld.cc

@@ -5371,7 +5371,7 @@ The minimum value for this variable is 4096.",
     "Limit assumed max number of seeks when looking up rows based on a key",
     (gptr*) &global_system_variables.max_seeks_for_key,
     (gptr*) &max_system_variables.max_seeks_for_key, 0, GET_ULONG,
-    REQUIRED_ARG, ~0L, 1, ~0L, 0, 1, 0 },
+    REQUIRED_ARG, UINT_MAX32, 1, UINT_MAX32, 0, 1, 0 },
   {"max_sort_length", OPT_MAX_SORT_LENGTH,
    "The number of bytes to use when sorting BLOB or TEXT values (only the first max_sort_length bytes of each value are used; the rest are ignored).",
    (gptr*) &global_system_variables.max_sort_length,

sql/set_var.cc

@@ -1679,7 +1679,7 @@ Item *sys_var::item(THD *thd, enum_var_type var_type, LEX_STRING *base)
     pthread_mutex_lock(&LOCK_global_system_variables);
     value= *(uint*) value_ptr(thd, var_type, base);
     pthread_mutex_unlock(&LOCK_global_system_variables);
-    return new Item_uint((int32) value);
+    return new Item_uint((uint32) value);
   }
   case SHOW_LONG:
   {
@@ -1687,7 +1687,7 @@ Item *sys_var::item(THD *thd, enum_var_type var_type, LEX_STRING *base)
     pthread_mutex_lock(&LOCK_global_system_variables);
     value= *(ulong*) value_ptr(thd, var_type, base);
     pthread_mutex_unlock(&LOCK_global_system_variables);
-    return new Item_uint((int32) value);
+    return new Item_uint(value);
   }
   case SHOW_LONGLONG:
   {