Apply URL decoding for nested jar entry names

Update `JarURLConnection` to apply URL decoding to nested jar entry
names.

Fixes gh-12765

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/JarURLConnection.java

@@ -258,10 +258,10 @@ final class JarURLConnection extends java.net.JarURLConnection {
 		int separator;
 		int index = 0;
 		while ((separator = spec.indexOf(SEPARATOR, index)) > 0) {
-			String entryName = spec.substring(index, separator);
-			JarEntry jarEntry = jarFile.getJarEntry(entryName);
+			JarEntryName entryName = JarEntryName.get(spec.substring(index, separator));
+			JarEntry jarEntry = jarFile.getJarEntry(entryName.toString());
 			if (jarEntry == null) {
-				return JarURLConnection.notFound(jarFile, JarEntryName.get(entryName));
+				return JarURLConnection.notFound(jarFile, entryName);
 			}
 			jarFile = jarFile.getNestedJarFile(jarEntry);
 			index += separator + SEPARATOR.length();

spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/TestJarCreator.java

@@ -52,6 +52,7 @@ public abstract class TestJarCreator {
 
 			writeNestedEntry("nested.jar", unpackNested, jarOutputStream);
 			writeNestedEntry("another-nested.jar", unpackNested, jarOutputStream);
+			writeNestedEntry("space nested.jar", unpackNested, jarOutputStream);
 		}
 		finally {
 			jarOutputStream.close();

spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/archive/ExplodedArchiveTests.java

@@ -108,7 +108,7 @@ public class ExplodedArchiveTests {
 	@Test
 	public void getEntries() throws Exception {
 		Map<String, Archive.Entry> entries = getEntriesMap(this.archive);
-		assertThat(entries.size()).isEqualTo(10);
+		assertThat(entries.size()).isEqualTo(11);
 	}
 
 	@Test

spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/archive/JarFileArchiveTests.java

@@ -82,7 +82,7 @@ public class JarFileArchiveTests {
 	@Test
 	public void getEntries() throws Exception {
 		Map<String, Archive.Entry> entries = getEntriesMap(this.archive);
-		assertThat(entries.size()).isEqualTo(10);
+		assertThat(entries.size()).isEqualTo(11);
 	}
 
 	@Test

spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/CentralDirectoryParserTests.java

@@ -90,6 +90,7 @@ public class CentralDirectoryParserTests {
 		assertThat(headers.next().getName().toString()).isEqualTo("special/\u00EB.dat");
 		assertThat(headers.next().getName().toString()).isEqualTo("nested.jar");
 		assertThat(headers.next().getName().toString()).isEqualTo("another-nested.jar");
+		assertThat(headers.next().getName().toString()).isEqualTo("space nested.jar");
 		assertThat(headers.hasNext()).isFalse();
 	}
 

spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/JarFileTests.java

@@ -93,6 +93,7 @@ public class JarFileTests {
 		assertThat(entries.nextElement().getName()).isEqualTo("special/\u00EB.dat");
 		assertThat(entries.nextElement().getName()).isEqualTo("nested.jar");
 		assertThat(entries.nextElement().getName()).isEqualTo("another-nested.jar");
+		assertThat(entries.nextElement().getName()).isEqualTo("space nested.jar");
 		assertThat(entries.hasMoreElements()).isFalse();
 		URL jarUrl = new URL("jar:" + this.rootJarFile.toURI() + "!/");
 		URLClassLoader urlClassLoader = new URLClassLoader(new URL[] { jarUrl });
@@ -135,6 +136,7 @@ public class JarFileTests {
 		assertThat(entries.nextElement().getName()).isEqualTo("special/\u00EB.dat");
 		assertThat(entries.nextElement().getName()).isEqualTo("nested.jar");
 		assertThat(entries.nextElement().getName()).isEqualTo("another-nested.jar");
+		assertThat(entries.nextElement().getName()).isEqualTo("space nested.jar");
 		assertThat(entries.hasMoreElements()).isFalse();
 	}
 

spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/JarURLConnectionTests.java

@@ -137,6 +137,21 @@ public class JarURLConnectionTests {
 				.hasSameContentAs(new ByteArrayInputStream(new byte[] { 3 }));
 	}
 
+	@Test
+	public void connectionToEntryWithSpaceNestedEntry() throws Exception {
+		URL url = new URL("jar:file:" + getRelativePath() + "!/space nested.jar!/3.dat");
+		assertThat(JarURLConnection.get(url, this.jarFile).getInputStream())
+				.hasSameContentAs(new ByteArrayInputStream(new byte[] { 3 }));
+	}
+
+	@Test
+	public void connectionToEntryWithEncodedSpaceNestedEntry() throws Exception {
+		URL url = new URL(
+				"jar:file:" + getRelativePath() + "!/space%20nested.jar!/3.dat");
+		assertThat(JarURLConnection.get(url, this.jarFile).getInputStream())
+				.hasSameContentAs(new ByteArrayInputStream(new byte[] { 3 }));
+	}
+
 	@Test
 	public void getContentLengthReturnsLengthOfUnderlyingEntry() throws Exception {
 		URL url = new URL(new URL("jar", null, -1,