Exclude FileEditor from binding conversion

Exclude `FileEditor` from the `BindConverter` since it uses slightly
unusual logic to create the file. Specifically, given a value of "."
the editor will locate a `ClassPathResource` then return `getFile()`
from that resource. For back-compatibility, binding should use the
simpler conversion service logic.

Fixes gh-12163

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/BindConverter.java

@@ -20,6 +20,7 @@ import java.beans.PropertyEditor;
 import java.lang.annotation.Annotation;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Consumer;
@@ -27,6 +28,7 @@ import java.util.function.Consumer;
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.PropertyEditorRegistry;
 import org.springframework.beans.SimpleTypeConverter;
+import org.springframework.beans.propertyeditors.FileEditor;
 import org.springframework.boot.convert.ApplicationConversionService;
 import org.springframework.core.ResolvableType;
 import org.springframework.core.convert.ConversionService;
@@ -43,6 +45,13 @@ import org.springframework.util.Assert;
  */
 class BindConverter {
 
+	private static final Set<Class<?>> EXCLUDED_EDITORS;
+	static {
+		Set<Class<?>> excluded = new HashSet<>();
+		excluded.add(FileEditor.class); // gh-12163
+		EXCLUDED_EDITORS = Collections.unmodifiableSet(excluded);
+	}
+
 	private final ConversionService typeConverterConversionService;
 
 	private final ConversionService conversionService;
@@ -163,6 +172,9 @@ class BindConverter {
 			if (editor == null && String.class != type) {
 				editor = BeanUtils.findEditorByConvention(type);
 			}
+			if (editor == null || EXCLUDED_EDITORS.contains(editor.getClass())) {
+				return null;
+			}
 			return editor;
 		}
 

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/ConfigurationPropertiesTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.context.properties;
 
 import java.beans.PropertyEditorSupport;
+import java.io.File;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -737,6 +738,13 @@ public class ConfigurationPropertiesTests {
 		assertThat(bean.getList()).containsExactly(RuntimeException.class);
 	}
 
+	@Test
+	public void loadWhenBindingCurrentDirectoryToFileShouldBind() {
+		load(FileProperties.class, "test.file=.");
+		FileProperties bean = this.context.getBean(FileProperties.class);
+		assertThat(bean.getFile()).isEqualTo(new File("."));
+	}
+
 	private AnnotationConfigApplicationContext load(Class<?> configuration,
 			String... inlinedProperties) {
 		return load(new Class<?>[] { configuration }, inlinedProperties);
@@ -1624,6 +1632,22 @@ public class ConfigurationPropertiesTests {
 
 	}
 
+	@EnableConfigurationProperties
+	@ConfigurationProperties(prefix = "test")
+	static class FileProperties {
+
+		private File file;
+
+		public File getFile() {
+			return this.file;
+		}
+
+		public void setFile(File file) {
+			this.file = file;
+		}
+
+	}
+
 	static class CustomPropertiesValidator implements Validator {
 
 		@Override

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/BindConverterTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.context.properties.bind;
 
 import java.beans.PropertyEditorSupport;
+import java.io.File;
 import java.util.List;
 import java.util.function.Consumer;
 
@@ -195,6 +196,18 @@ public class BindConverterTests {
 		bindConverter.convert("test", ResolvableType.forClass(SampleType.class));
 	}
 
+	@Test
+	public void convertWhenConvertingToFileShouldExcludeFileEditor() {
+		// For back compatibility we want true file conversion and not an accidental
+		// classpath resource reference. See gh-12163
+		BindConverter bindConverter = new BindConverter(new GenericConversionService(),
+				null);
+		assertThat(bindConverter.canConvert(".", ResolvableType.forClass(File.class)))
+				.isFalse();
+		this.thrown.expect(ConverterNotFoundException.class);
+		bindConverter.convert(".", ResolvableType.forClass(File.class));
+	}
+
 	private BindConverter getPropertyEditorOnlyBindConverter(
 			Consumer<PropertyEditorRegistry> propertyEditorInitializer) {
 		return new BindConverter(new ThrowingConversionService(),