[fix](function)width_bucket did not enforce that the fourth argument must be a constant. (#60643)

The implementation of width_bucket requires the fourth argument to be
constant but did not enforce this; a regular column can be passed in,
however width_bucket will only use the first row.
before
```sql
mysql> SELECT k1, v1, v2, v3, width_bucket(v1, date('2023-11-18'), date('2027-11-18'), v4) AS w FROM width_bucket_test ORDER BY k1;
+------+------------+-----------+--------+------+
| k1   | v1         | v2        | v3     | w    |
+------+------------+-----------+--------+------+
|    1 | 2022-11-18 |    290000 | 290000 |    0 |
|    2 | 2023-11-18 |    320000 | 320000 |    1 |
|    3 | 2024-11-18 | 399999.99 | 399999 |    1 |
|    4 | 2025-11-18 |    400000 | 400000 |    1 |
|    5 | 2026-11-18 |    470000 | 470000 |    1 |
|    6 | 2027-11-18 |    510000 | 510000 |    2 |
|    7 | 2028-11-18 |    610000 | 610000 |    2 |
|    8 | NULL       |      NULL |   NULL | NULL |
+------+------------+-----------+--------+------+
```
now
```sql
mysql>  SELECT k1, v1, v2, v3, width_bucket(v1, date('2023-11-18'), date('2027-11-18'), v4) AS w FROM width_bucket_test ORDER BY k1;
ERROR 1105 (HY000): errCode = 2, detailMessage = The fourth argument of WidthBucket must be a constant.
```

Author: Mryange

be/src/vec/functions/function_width_bucket.cpp

@@ -68,8 +68,7 @@ class FunctionWidthBucket : public IFunction {
                 block.get_by_position(arguments[1]).column->convert_to_full_column_if_const();
         ColumnPtr max_value_ptr =
                 block.get_by_position(arguments[2]).column->convert_to_full_column_if_const();
-        ColumnPtr num_buckets_ptr =
-                block.get_by_position(arguments[3]).column->convert_to_full_column_if_const();
+        ColumnPtr num_buckets_ptr = block.get_by_position(arguments[3]).column;
         int64_t num_buckets = num_buckets_ptr->get_int(0);
 
         if (num_buckets <= 0) {

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/scalar/WidthBucket.java

@@ -18,6 +18,7 @@
 package org.apache.doris.nereids.trees.expressions.functions.scalar;
 
 import org.apache.doris.catalog.FunctionSignature;
+import org.apache.doris.nereids.exceptions.AnalysisException;
 import org.apache.doris.nereids.trees.expressions.Expression;
 import org.apache.doris.nereids.trees.expressions.functions.ExplicitlyCastableSignature;
 import org.apache.doris.nereids.trees.expressions.functions.PropagateNullable;
@@ -74,6 +75,18 @@ public WidthBucket withChildren(List<Expression> children) {
         return new WidthBucket(getFunctionParams(children));
     }
 
+    @Override
+    public void checkLegalityBeforeTypeCoercion() {
+        if (!child(3).isLiteral()) {
+            throw new AnalysisException("The fourth argument of WidthBucket must be a constant.");
+        }
+    }
+
+    @Override
+    public void checkLegalityAfterRewrite() {
+        checkLegalityBeforeTypeCoercion();
+    }
+
     @Override
     public List<FunctionSignature> getSignatures() {
         return SIGNATURES;

regression-test/suites/query_p0/sql_functions/width_bucket_fuctions/test_width_bucket_function.groovy

@@ -94,4 +94,10 @@ suite("test_width_bucket_function", "arrow_flight_sql") {
       sql "select width_bucket(4, 0, 8, 0)"
       exception "buckets must be a positive integer value"
     }
+
+
+    test {
+      sql "SELECT k1, width_bucket(v2, 200000, 600000, k1) FROM ${tableName2} ORDER BY k1"
+      exception "The fourth argument of WidthBucket must be a constant"
+    }
 }