fix: IS NULL panic with invalid function without input arguments (#20306)

## Which issue does this PR close?

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- Closes #20201 .

## Rationale for this change

Unlike `Projection`, expressions within a `Filter` node do not always
have their types resolved during the initial LogicalPlan generation.
Validation is often deferred until the type_coercion phase. When
invoking f_up on the expression tree to perform type coercion, the check
is bypassed for function nodes with empty arguments, leading to a panic
during subsequent execution.

For example, all statements below cause a panic:
```
SELECT * FROM (SELECT 1) WHERE (STARTS_WITH() IS NULL);
SELECT * FROM (SELECT 1) WHERE (STARTS_WITH() IS NOT NULL);
SELECT * FROM (SELECT 'a') WHERE (STARTS_WITH() SIMILAR TO 'abc%');
SELECT * FROM (SELECT 1) WHERE CAST(STARTS_WITH() AS STRING) = 'x';
SELECT * FROM (SELECT 1) WHERE TRY_CAST(STARTS_WITH() AS INT) IS NULL;
```

This pr aims to stop panic. It would be better if reject these invalid
cases at planning.

## What changes are included in this PR?

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is sometimes worth providing a summary of the individual changes in this
PR.
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```diff
 fn coerce_arguments_for_signature<F: UDFCoercionExt>(
      schema: &DFSchema,
      func: &F,
  ) -> Result<Vec<Expr>> {
-    if expressions.is_empty() {
-        return Ok(expressions);
-    }
```

Deleted the early return. Thanks to @neilconway .

## Are these changes tested?
All original tests passed. Added some unit tests and sqllogictests.


## Are there any user-facing changes?

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No.

---------

Co-authored-by: Andrew Lamb <andrew@nerdnetworks.org>

Author: Acfboy

datafusion/optimizer/src/analyzer/type_coercion.rs

@@ -954,10 +954,6 @@ fn coerce_arguments_for_signature<F: UDFCoercionExt>(
     schema: &DFSchema,
     func: &F,
 ) -> Result<Vec<Expr>> {
-    if expressions.is_empty() {
-        return Ok(expressions);
-    }
-
     let current_fields = expressions
         .iter()
         .map(|e| e.to_field(schema).map(|(_, f)| f))

datafusion/sqllogictest/test_files/type_coercion.slt

@@ -281,3 +281,24 @@ SELECT true FROM t0 WHERE (REGEXP_MATCH(t0.v1, t0.v1)) NOT ILIKE [];
 
 statement ok
 DROP TABLE t0;
+
+#############################################################
+## Test validation for functions with empty argument lists ##
+#############################################################
+
+# https://github.com/apache/datafusion/issues/20201
+
+query error does not support zero arguments
+SELECT * FROM (SELECT 1) WHERE (STARTS_WITH() IS NULL);
+
+query error does not support zero arguments
+SELECT * FROM (SELECT 1) WHERE (STARTS_WITH() IS NOT NULL);
+
+query error does not support zero arguments
+SELECT * FROM (SELECT 'a') WHERE (STARTS_WITH() SIMILAR TO 'abc%');
+
+query error does not support zero arguments
+SELECT * FROM (SELECT 1) WHERE CAST(STARTS_WITH() AS STRING) = 'x';
+
+query error does not support zero arguments
+SELECT * FROM (SELECT 1) WHERE TRY_CAST(STARTS_WITH() AS INT) = 1;