diff --git a/mysql-test/r/func_in.result b/mysql-test/r/func_in.result
index fdeec2755ca..0b6117581f3 100644
--- a/mysql-test/r/func_in.result
+++ b/mysql-test/r/func_in.result
@@ -770,4 +770,10 @@ CASE a WHEN a THEN a END
 NULL
 DROP TABLE t1;
 #
+# Bug #11766212  59270: NOT IN (YEAR( ... ), ... ) PRODUCES MANY VALGRIND WARNINGS
+#
+SELECT 1 IN (YEAR(FROM_UNIXTIME(NULL)) ,1);
+1 IN (YEAR(FROM_UNIXTIME(NULL)) ,1)
+1
+#
 End of 5.1 tests
diff --git a/mysql-test/t/func_in.test b/mysql-test/t/func_in.test
index 6efeb2866e6..08469b37967 100644
--- a/mysql-test/t/func_in.test
+++ b/mysql-test/t/func_in.test
@@ -554,6 +554,12 @@ SELECT CASE a WHEN a THEN a END FROM t1 GROUP BY a WITH ROLLUP;
 
 DROP TABLE t1;
 
+--echo #
+--echo # Bug #11766212  59270: NOT IN (YEAR( ... ), ... ) PRODUCES MANY VALGRIND WARNINGS
+--echo #
+
+SELECT 1 IN (YEAR(FROM_UNIXTIME(NULL)) ,1);
+
 --echo #
 
 --echo End of 5.1 tests
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 36ca5537eb5..23f081e1cc0 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -4000,13 +4000,11 @@ void Item_func_in::fix_length_and_dec()
       uint j=0;
       for (uint i=1 ; i < arg_count ; i++)
       {
-	if (!args[i]->null_value)			// Skip NULL values
-        {
-          array->set(j,args[i]);
-	  j++;
-        }
-	else
-	  have_null= 1;
+        array->set(j,args[i]);
+        if (!args[i]->null_value)                      // Skip NULL values
+          j++;
+        else
+          have_null= 1;
       }
       if ((array->used_count= j))
 	array->sort();