Use PropertyPath instead of utility methods

Prior to this commit, `DataBinder` and the property accessor
hierarchy relied on `PropertyAccessorUtils` and several
independent scanners for property paths.
This commit migrates all of them to `PropertyPath`, so
there is exactly one parser deciding what a well-formed property
path is, used identically for policy checks and for actual
navigation.

This removes long standing protected methods like
A`getPropertyAccessorForPropertyPathi` and `getFinalPath` from
`bstractNestablePropertyAccessor`. The path is now parsed exactly
once per public entry point, via the new `resolvePropertyPath`, which
returns a `ResolvedProperty`. Then, property navigation walks
the parsed segment list rather than re-scanning partial strings.
Any subclass overriding the removed method will need to adapt.

This removal initially conflicted with gh-37252 (maxNestedPathDepth
support). The public configuration remains but the actual behavior
changed; it is replaced with `PropertyPath.Options` which enforces
limit right after parsing, before property navigation begins.
The exception thrown changes from `InvalidPropertyException` to
`InvalidPropertyPathException`.

This commmit also reverts the `map[']` / `map["]` quoting behavior
from gh-36765 as it is incompatible with the new grammar.

See gh-37275

spring-context/src/test/java/org/springframework/validation/DataBinderFieldAccessTests.java

@@ -23,6 +23,7 @@ import java.util.Map;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.InvalidPropertyException;
+import org.springframework.beans.InvalidPropertyPathException;
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.NotWritablePropertyException;
 import org.springframework.beans.NullValueInNestedPathException;
@@ -162,7 +163,7 @@ class DataBinderFieldAccessTests {
 		rod.setSpouse(kerry);
 		kerry.setSpouse(rod);
 
-		DataBinder binder = new DataBinder(rod);
+		DataBinder binder = new DataBinder(rod, "rod");
 		binder.setMaxNestedPathDepth(2);
 		binder.initDirectFieldAccess();
 
@@ -173,9 +174,11 @@ class DataBinderFieldAccessTests {
 
 		MutablePropertyValues tooDeep = new MutablePropertyValues();
 		tooDeep.add("spouse.spouse.spouse.name", "Joe");
-		assertThatExceptionOfType(InvalidPropertyException.class)
-				.isThrownBy(() -> binder.bind(tooDeep))
-				.withMessageEndingWith("Nesting depth of property path exceeds the maximum of 2");
+		binder.bind(tooDeep);
+		assertThat(binder.getBindingResult().getFieldErrors("spouse.spouse.spouse.name")).singleElement().satisfies(error -> {
+			assertThat(error.getCode()).isEqualTo(InvalidPropertyPathException.ERROR_CODE);
+			assertThat(error.getRejectedValue()).isEqualTo("Joe");
+		});
 	}
 
 	@Test

spring-context/src/test/java/org/springframework/validation/DataBinderTests.java

@@ -42,6 +42,7 @@ import org.junit.jupiter.api.Test;
 import org.springframework.beans.BeanWrapper;
 import org.springframework.beans.ConfigurablePropertyAccessor;
 import org.springframework.beans.InvalidPropertyException;
+import org.springframework.beans.InvalidPropertyPathException;
 import org.springframework.beans.MethodInvocationException;
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.NotWritablePropertyException;
@@ -735,6 +736,56 @@ class DataBinderTests {
 		assertThat(binder.getBindingResult().getSuppressedFields()).containsExactlyInAnyOrder("age", "favoriteColor");
 	}
 
+	@Test  // gh-37275
+	void bindingWithMalformedFieldNameSurfacesAsFieldErrorRatherThanBeingSilentlyDropped() throws BindException {
+		TestBean rod = new TestBean();
+		DataBinder binder = new DataBinder(rod, "rod");
+		MutablePropertyValues pvs = new MutablePropertyValues();
+		pvs.add("name", "Rod");
+		pvs.add("map[key1]other", "value");  // trailing garbage after a key: not a well-formed property path
+
+		binder.bind(pvs);
+
+		assertThat(rod.getName()).as("well-formed fields still bind").isEqualTo("Rod");
+		assertThat(binder.getBindingResult().getFieldErrors("map[key1]other")).singleElement().satisfies(error -> {
+			assertThat(error.getCode()).isEqualTo(InvalidPropertyPathException.ERROR_CODE);
+			assertThat(error.getRejectedValue()).isEqualTo("value");
+		});
+		assertThatExceptionOfType(BindException.class).isThrownBy(binder::close);
+	}
+
+	@Test  // gh-37275
+	void bindingWithMalformedFieldNameIsNotSuppressedEvenWhenAllowedFieldsAreConfigured() throws BindException {
+		TestBean rod = new TestBean();
+		DataBinder binder = new DataBinder(rod, "rod");
+		binder.setAllowedFields("name");
+		MutablePropertyValues pvs = new MutablePropertyValues();
+		pvs.add("name", "Rod");
+		pvs.add("map[key1]other", "value");
+
+		binder.bind(pvs);
+
+		assertThat(binder.getBindingResult().getSuppressedFields()).isEmpty();
+		assertThat(binder.getBindingResult().getFieldErrors("map[key1]other")).hasSize(1);
+	}
+
+	@Test  // gh-37275
+	void isAllowedNeverThrowsForMalformedField() {
+		class ExposingBinder extends DataBinder {
+			ExposingBinder(Object target) {
+				super(target, "target");
+			}
+			boolean callIsAllowed(String field) {
+				return isAllowed(field);
+			}
+		}
+
+		ExposingBinder binder = new ExposingBinder(new TestBean());
+		binder.setAllowedFields("name");
+
+		assertThat(binder.callIsAllowed("map[key1]other")).isFalse();
+	}
+
 	@Test
 	@SuppressWarnings("removal")
 	void bindingWithAllowedAndDisallowedFields() throws BindException {
@@ -2080,7 +2131,7 @@ class DataBinderTests {
 		rod.setSpouse(kerry);
 		kerry.setSpouse(rod);
 
-		DataBinder binder = new DataBinder(rod);
+		DataBinder binder = new DataBinder(rod, "rod");
 		binder.setMaxNestedPathDepth(2);
 
 		MutablePropertyValues pvs = new MutablePropertyValues();
@@ -2090,9 +2141,11 @@ class DataBinderTests {
 
 		MutablePropertyValues tooDeep = new MutablePropertyValues();
 		tooDeep.add("spouse.spouse.spouse.name", "Joe");
-		assertThatExceptionOfType(InvalidPropertyException.class)
-				.isThrownBy(() -> binder.bind(tooDeep))
-				.withMessageEndingWith("Nesting depth of property path exceeds the maximum of 2");
+		binder.bind(tooDeep);
+		assertThat(binder.getBindingResult().getFieldErrors("spouse.spouse.spouse.name")).singleElement().satisfies(error -> {
+			assertThat(error.getCode()).isEqualTo(InvalidPropertyPathException.ERROR_CODE);
+			assertThat(error.getRejectedValue()).isEqualTo("Joe");
+		});
 	}
 
 	@Test  // gh-37252