Fix Windows function lag()/lead() function throw AnalysisException.

fe/fe-core/src/main/java/org/apache/doris/analysis/DecimalLiteral.java

@@ -224,7 +224,9 @@ public int getFracValue() {
 
     @Override
     protected Expr uncheckedCastTo(Type targetType) throws AnalysisException {
-        if (targetType.isFloatingPointType()) {
+        if (targetType.isDecimal() || targetType.isDecimalV2()) {
+            return this;
+        } else if (targetType.isFloatingPointType()) {
             return new FloatLiteral(value.doubleValue(), targetType);
         } else if (targetType.isIntegerType()) {
             return new IntLiteral(value.longValue(), targetType);

fe/fe-core/src/main/java/org/apache/doris/catalog/FunctionSet.java

@@ -754,7 +754,9 @@ public static boolean isCastMatchAllowed(Function desc, Function candicate) {
         final Type[] candicateArgTypes = candicate.getArgs();
         if (functionName.equalsIgnoreCase("hex")
                 || functionName.equalsIgnoreCase("greast")
-                || functionName.equalsIgnoreCase("least")) {
+                || functionName.equalsIgnoreCase("least")
+                || functionName.equalsIgnoreCase("lead")
+                || functionName.equalsIgnoreCase("lag")) {
             final ScalarType descArgType = (ScalarType)descArgTypes[0];
             final ScalarType candicateArgType = (ScalarType)candicateArgTypes[0];
             if (!descArgType.isStringType() && candicateArgType.isStringType()) {

fe/fe-core/src/test/java/org/apache/doris/analysis/DecimalLiteralTest.java

@@ -19,6 +19,8 @@
 
 import org.apache.doris.catalog.PrimitiveType;
 
+import org.apache.doris.catalog.Type;
+import org.apache.doris.common.AnalysisException;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -28,7 +30,7 @@
 public class DecimalLiteralTest {
 
     @Test
-    public void testHashValue() {
+    public void testHashValue() throws AnalysisException {
         BigDecimal decimal = new BigDecimal("-123456789123456789.123456789");
         DecimalLiteral literal = new DecimalLiteral(decimal);
 
@@ -40,6 +42,11 @@ public void testHashValue() {
         Assert.assertEquals(-123456789123456789L, longValue);
         Assert.assertEquals(-123456789, fracValue);
 
+        // if DecimalLiteral need to cast to Decimal and Decimalv2, need to cast
+        // to themselves
+        Assert.assertEquals(literal, literal.uncheckedCastTo(Type.DECIMAL));
+        Assert.assertEquals(literal, literal.uncheckedCastTo(Type.DECIMALV2));
+
         Assert.assertEquals(1, literal.compareLiteral(new NullLiteral()));
     }
 }

fe/fe-core/src/test/java/org/apache/doris/catalog/FunctionSetTest.java

@@ -0,0 +1,53 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package org.apache.doris.catalog;
+
+import org.apache.doris.analysis.FunctionName;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+public class FunctionSetTest {
+
+    private FunctionSet functionSet;
+
+    @Before
+    public void setUp() {
+        functionSet = new FunctionSet();
+        functionSet.init();
+    }
+
+    @Test
+    public void testGetLagFunction() {
+        Type[] argTypes1 = {ScalarType.DECIMAL, ScalarType.TINYINT, ScalarType.TINYINT};
+        Function lagDesc1 = new Function(new FunctionName("lag"), argTypes1, (Type) ScalarType.INVALID, false);
+        Function newFunction = functionSet.getFunction(lagDesc1, Function.CompareMode.IS_SUPERTYPE_OF);
+        Type[] newArgTypes = newFunction.getArgs();
+        Assert.assertTrue(newArgTypes[0].matchesType(newArgTypes[2]));
+        Assert.assertTrue(newArgTypes[0].matchesType(ScalarType.DECIMAL));
+
+        Type[] argTypes2 = {ScalarType.VARCHAR, ScalarType.TINYINT, ScalarType.TINYINT};
+        Function lagDesc2 = new Function(new FunctionName("lag"), argTypes2, (Type) ScalarType.INVALID, false);
+        newFunction = functionSet.getFunction(lagDesc2, Function.CompareMode.IS_SUPERTYPE_OF);
+        newArgTypes = newFunction.getArgs();
+        Assert.assertTrue(newArgTypes[0].matchesType(newArgTypes[2]));
+        Assert.assertTrue(newArgTypes[0].matchesType(ScalarType.VARCHAR));
+    }
+
+}