branch-3.0: [Bug](intersect) fix wrong result of intersect with null literal #50951 (#51178)

Cherry-picked from #50951

Co-authored-by: Pxl <xl@selectdb.com>

Author: github-actions[bot]

fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/PullUpPredicates.java

@@ -21,6 +21,7 @@
 import org.apache.doris.nereids.trees.expressions.EqualTo;
 import org.apache.doris.nereids.trees.expressions.Expression;
 import org.apache.doris.nereids.trees.expressions.InPredicate;
+import org.apache.doris.nereids.trees.expressions.IsNull;
 import org.apache.doris.nereids.trees.expressions.NamedExpression;
 import org.apache.doris.nereids.trees.expressions.Slot;
 import org.apache.doris.nereids.trees.expressions.functions.agg.AggregateFunction;
@@ -134,7 +135,7 @@ public ImmutableSet<Expression> visitLogicalOneRowRelation(LogicalOneRowRelation
             Set<Expression> predicates = new LinkedHashSet<>();
             for (NamedExpression expr : r.getProjects()) {
                 if (expr instanceof Alias && expr.child(0) instanceof Literal) {
-                    predicates.add(new EqualTo(expr.toSlot(), expr.child(0)));
+                    predicates.add(generateEqual(expr));
                 }
             }
             return ImmutableSet.copyOf(predicates);
@@ -262,7 +263,7 @@ public ImmutableSet<Expression> visitLogicalProject(LogicalProject<? extends Pla
             }
             for (NamedExpression expr : project.getProjects()) {
                 if (expr instanceof Alias && expr.child(0) instanceof Literal) {
-                    allPredicates.add(new EqualTo(expr.toSlot(), expr.child(0)));
+                    allPredicates.add(generateEqual(expr));
                 }
             }
             return getAvailableExpressions(allPredicates, project);
@@ -379,4 +380,13 @@ private ImmutableSet<Expression> getFiltersFromUnionConstExprs(LogicalUnion unio
         }
         return ImmutableSet.copyOf(filtersFromConstExprs);
     }
+
+    private Expression generateEqual(NamedExpression expr) {
+        // IsNull have better performance and compatibility than NullSafeEqualTo
+        if (expr.child(0) instanceof NullLiteral) {
+            return new IsNull(expr.toSlot());
+        } else {
+            return new EqualTo(expr.toSlot(), expr.child(0));
+        }
+    }
 }