Optimize IN(...) queries: there was a bug in version 1.3.170 for comparison of…

Optimize IN(...) queries: there was a bug in version 1.3.170 for comparison of the type "X IN(NULL, NULL)". Fixed.

h2/src/docsrc/html/changelog.html

@@ -18,7 +18,9 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>Timestamps with timezone that were passed as a string were not always
+<ul><li>Optimize IN(...) queries: there was a bug in version 1.3.170 for comparison of the type
+    "X IN(NULL, NULL)". Fixed.
+</li><li>Timestamps with timezone that were passed as a string were not always
     converted correctly. For example "2012-11-06T23:00:00.000Z" was converted to
     "2012-11-06" instead of to "2012-11-07" in the timezone CET.
     Thanks a lot to Steve Hruda for reporting the problem!

h2/src/main/org/h2/expression/ConditionIn.java

@@ -81,11 +81,15 @@ public class ConditionIn extends Condition {
         }
         boolean allValuesConstant = true;
         boolean allValuesSameType = true;
+        boolean allValuesNull = true;
         int size = valueList.size();
         Expression lastExpr = null;
         for (int i = 0; i < size; i++) {
             Expression e = valueList.get(i);
             e = e.optimize(session);
+            if (e.isConstant() && e.getValue(session) != ValueNull.INSTANCE) {
+                allValuesNull = false;
+            }
             if (allValuesConstant && !e.isConstant()) {
                 allValuesConstant = false;
             }
@@ -104,7 +108,7 @@ public class ConditionIn extends Condition {
             expr = expr.optimize(session);
             return expr;
         }
-        if (allValuesConstant && allValuesSameType) {
+        if (allValuesConstant && allValuesSameType && !allValuesNull) {
             Expression expr = new ConditionInConstantSet(session, left, valueList);
             expr = expr.optimize(session);
             return expr;

h2/src/main/org/h2/expression/ConditionInConstantSet.java

@@ -53,14 +53,24 @@ public class ConditionInConstantSet extends Condition {
         if (leftVal == ValueNull.INSTANCE) {
             return leftVal;
         }
-        boolean setHasNull = valueSet.contains(ValueNull.INSTANCE);
-        Value firstRightVal = valueSet.iterator().next();
-        leftVal = leftVal.convertTo(firstRightVal.getType());
+        Value firstRightValue = null;
+        for (Value v : valueSet) {
+            if (v != ValueNull.INSTANCE) {
+                firstRightValue = v;
+                break;
+            }
+        }
+        if (firstRightValue == null) {
+            throw DbException.throwInternalError();
+        }
+        leftVal = leftVal.convertTo(firstRightValue.getType());
         boolean result = valueSet.contains(leftVal);
-
-        if (!result && setHasNull) {
+        if (!result) {
+            boolean setHasNull = valueSet.contains(ValueNull.INSTANCE);
+            if (setHasNull) {
                 return ValueNull.INSTANCE;
             }
+        }
         return ValueBoolean.get(result);
     }
 

h2/src/test/org/h2/test/test-1.3.txt

@@ -23,6 +23,11 @@ create table test(id int, name varchar);
 insert into test values(5, 'b'), (5, 'b'), (20, 'a');
 > update count: 3
 
+select id from test where name in(null, null);
+> ID
+> --
+> rows: 0
+
 select * from (select * from test order by name limit 1) where id < 10;
 > ID NAME
 > -- ----