[CALCITE-4215] Avoid NPE when monotonicity is null
diff --git a/core/src/main/java/org/apache/calcite/sql/SqlBinaryOperator.java b/core/src/main/java/org/apache/calcite/sql/SqlBinaryOperator.java
index d28d3e9..287c317 100644
--- a/core/src/main/java/org/apache/calcite/sql/SqlBinaryOperator.java
+++ b/core/src/main/java/org/apache/calcite/sql/SqlBinaryOperator.java
@@ -153,6 +153,9 @@
if (getName().equals("/")) {
final SqlMonotonicity mono0 = call.getOperandMonotonicity(0);
final SqlMonotonicity mono1 = call.getOperandMonotonicity(1);
+ if (mono0 == null || mono1 == null) {
+ return null;
+ }
if (mono1 == SqlMonotonicity.CONSTANT) {
if (call.isOperandLiteral(1, false)) {
switch (call.getOperandLiteralValue(1, BigDecimal.class).signum()) {
diff --git a/core/src/main/java/org/apache/calcite/sql/fun/SqlSubstringFunction.java b/core/src/main/java/org/apache/calcite/sql/fun/SqlSubstringFunction.java
index 3366d70..952c3e9 100644
--- a/core/src/main/java/org/apache/calcite/sql/fun/SqlSubstringFunction.java
+++ b/core/src/main/java/org/apache/calcite/sql/fun/SqlSubstringFunction.java
@@ -160,7 +160,8 @@
// SUBSTRING(x FROM 0 FOR constant) has same monotonicity as x
if (call.getOperandCount() == 3) {
final SqlMonotonicity mono0 = call.getOperandMonotonicity(0);
- if ((mono0 != SqlMonotonicity.NOT_MONOTONIC)
+ if (mono0 != null
+ && mono0 != SqlMonotonicity.NOT_MONOTONIC
&& call.getOperandMonotonicity(1) == SqlMonotonicity.CONSTANT
&& call.getOperandLiteralValue(1, BigDecimal.class)
.equals(BigDecimal.ZERO)
