Ensure that file is released back to pool when seek fails

Closes gh-9370

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/data/RandomAccessDataFile.java

 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -170,11 +170,11 @@ public class RandomAccessDataFile implements RandomAccessData {
 				return -1;
 			}
 			RandomAccessFile file = this.file;
-			if (file == null) {
-				file = RandomAccessDataFile.this.filePool.acquire();
-				file.seek(RandomAccessDataFile.this.offset + this.position);
-			}
 			try {
+				if (file == null) {
+					file = RandomAccessDataFile.this.filePool.acquire();
+					file.seek(RandomAccessDataFile.this.offset + this.position);
+				}
 				if (b == null) {
 					int rtn = file.read();
 					moveOn(rtn == -1 ? 0 : 1);
@@ -185,7 +185,7 @@ public class RandomAccessDataFile implements RandomAccessData {
 				}
 			}
 			finally {
-				if (this.file == null) {
+				if (this.file == null && file != null) {
 					RandomAccessDataFile.this.filePool.release(file);
 				}
 			}
@@ -229,7 +229,7 @@ public class RandomAccessDataFile implements RandomAccessData {
 	 * Manage a pool that can be used to perform concurrent reads on the underlying
 	 * {@link RandomAccessFile}.
 	 */
-	private class FilePool {
+	class FilePool {
 
 		private final int size;
 

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

@@ -18,7 +18,9 @@ package org.springframework.boot.loader.data;
 
 import java.io.File;
 import java.io.FileOutputStream;
+import java.io.IOException;
 import java.io.InputStream;
+import java.io.RandomAccessFile;
 import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -35,10 +37,20 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 import org.junit.rules.TemporaryFolder;
+import org.mockito.internal.util.MockUtil;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
 
 import org.springframework.boot.loader.data.RandomAccessData.ResourceAccess;
+import org.springframework.boot.loader.data.RandomAccessDataFile.FilePool;
+import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.fail;
+import static org.mockito.BDDMockito.willAnswer;
+import static org.mockito.BDDMockito.willThrow;
+import static org.mockito.Matchers.anyLong;
+import static org.mockito.Mockito.spy;
 
 /**
  * Tests for {@link RandomAccessDataFile}.
@@ -309,4 +321,38 @@ public class RandomAccessDataFileTests {
 		assertThat(queue.size()).isEqualTo(0);
 	}
 
+	@Test
+	public void seekFailuresDoNotPreventSubsequentReads() throws Exception {
+		FilePool filePool = (FilePool) ReflectionTestUtils.getField(this.file,
+				"filePool");
+		FilePool spiedPool = spy(filePool);
+		ReflectionTestUtils.setField(this.file, "filePool", spiedPool);
+		willAnswer(new Answer<RandomAccessFile>() {
+
+			@Override
+			public RandomAccessFile answer(InvocationOnMock invocation) throws Throwable {
+				RandomAccessFile originalFile = (RandomAccessFile) invocation
+						.callRealMethod();
+				if (new MockUtil().isSpy(originalFile)) {
+					return originalFile;
+				}
+				RandomAccessFile spiedFile = spy(originalFile);
+				willThrow(new IOException("Seek failed")).given(spiedFile)
+						.seek(anyLong());
+				return spiedFile;
+			}
+
+		}).given(spiedPool).acquire();
+
+		for (int i = 0; i < 5; i++) {
+			try {
+				this.file.getInputStream(ResourceAccess.PER_READ).read();
+				fail("Read should fail due to exception from seek");
+			}
+			catch (IOException ex) {
+
+			}
+		}
+	}
+
 }