Verify PathMatchingResourcePatternResolver finds local files with # in name

This commit introduces a test that verifies that
PathMatchingResourcePatternResolver can find files in the filesystem
that contain hashtags (#) in their names.

See gh-23532

spring-core/src/test/java/org/springframework/core/io/support/PathMatchingResourcePatternResolverTests.java

@@ -16,6 +16,7 @@
 
 package org.springframework.core.io.support;
 
+import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -96,6 +97,13 @@ class PathMatchingResourcePatternResolverTests {
 				StringUtils.concatenateStringArrays(CLASSES_IN_CORE_IO_SUPPORT, TEST_CLASSES_IN_CORE_IO_SUPPORT));
 	}
 
+	@Test
+	void getResourcesOnFileSystemContainingHashtagsInTheirFileNames() throws IOException {
+		Resource[] resources = resolver.getResources("classpath*:org/springframework/core/io/**/resource#test*.txt");
+		assertThat(resources).extracting(Resource::getFile).extracting(File::getName)
+			.containsExactlyInAnyOrder("resource#test1.txt", "resource#test2.txt");
+	}
+
 	@Test
 	void classpathWithPatternInJar() throws IOException {
 		Resource[] resources = resolver.getResources("classpath:org/reactivestreams/*.class");

spring-core/src/test/resources/org/springframework/core/io/support/resource#test1.txt

@@ -0,0 +1 @@
+test 1

spring-core/src/test/resources/org/springframework/core/io/support/resource#test2.txt

@@ -0,0 +1 @@
+test 2