Delay creation of index conditions for ON conditions to avoid NPE

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,10 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>Issue #1762: NullPointerException in Parser. Introduced in 1.4.198
+</li>
+<li>PR #1768: Add more context-sensitive keywords
+</li>
 <li>Issue #1758: sequence restart issue with 1.4.198
 </li>
 <li>Issue #1759: SELECT &#8230; FOR UPDATE returns old data in 1.4.198

h2/src/main/org/h2/command/dml/Select.java

@@ -1382,6 +1382,7 @@ public class Select extends Query {
     private double preparePlan(boolean parse) {
         TableFilter[] topArray = topFilters.toArray(new TableFilter[0]);
         for (TableFilter t : topArray) {
+            t.createIndexConditions();
             t.setFullCondition(condition);
         }
 

h2/src/main/org/h2/table/TableFilter.java

@@ -93,6 +93,11 @@ public class TableFilter implements ColumnResolver {
      */
     private Expression filterCondition;
 
+    /**
+     * Initial ON condition.
+     */
+    private Expression onCondition;
+
     /**
      * The complete join condition.
      */
@@ -709,18 +714,32 @@ public class TableFilter implements ColumnResolver {
      * @param on the condition
      */
     public void mapAndAddFilter(Expression on) {
+        this.onCondition = on;
         on.mapColumns(this, 0, Expression.MAP_INITIAL);
         addFilterCondition(on, true);
-        on.createIndexConditions(session, this);
         if (nestedJoin != null) {
             on.mapColumns(nestedJoin, 0, Expression.MAP_INITIAL);
-            on.createIndexConditions(session, nestedJoin);
         }
         if (join != null) {
             join.mapAndAddFilter(on);
         }
     }
 
+    public void createIndexConditions() {
+        if (onCondition != null) {
+            onCondition.createIndexConditions(session, this);
+            if (nestedJoin != null) {
+                onCondition.createIndexConditions(session, nestedJoin);
+            }
+        }
+        if (join != null) {
+            join.createIndexConditions();
+        }
+        if (nestedJoin != null) {
+            nestedJoin.createIndexConditions();
+        }
+    }
+
     public TableFilter getJoin() {
         return join;
     }

h2/src/test/org/h2/test/scripts/joins.sql

@@ -785,3 +785,20 @@ SELECT T1.X1, T2.X2, T3.X3, T4.X4, T5.X5 FROM (
 > -- -- -- -- --
 > 1  1  1  1  1
 > rows: 1
+
+CREATE TABLE A(X INT);
+> ok
+
+CREATE TABLE B(Y INT);
+> ok
+
+CREATE TABLE C(Z INT);
+> ok
+
+SELECT A.X FROM A JOIN B ON A.X = B.Y AND B.Y >= COALESCE((SELECT Z FROM C FETCH FIRST ROW ONLY), 0);
+> X
+> -
+> rows: 0
+
+DROP TABLE A, B, C;
+> ok