Add tests to check workaround will terminate properly on bad images.

src/test/java/net/coobird/thumbnailator/tasks/io/InputStreamImageSourceMalformedTest.java

@@ -0,0 +1,96 @@
+/*
+ * Thumbnailator - a thumbnail generation library
+ *
+ * Copyright (c) 2008-2021 Chris Kroells
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package net.coobird.thumbnailator.tasks.io;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.io.ByteArrayInputStream;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+
+@RunWith(Parameterized.class)
+public class InputStreamImageSourceMalformedTest {
+
+	@Parameterized.Parameters(name = "type={0}, length={1}")
+	public static Collection<Object> testCases() {
+		List<Object[]> cases = new ArrayList<Object[]>();
+		for (String type : Arrays.asList("jpg", "png", "bmp")) {
+			for (int i = 1; i <= 40; i++) {
+				cases.add(new Object[] { type, i });
+			}
+		}
+		return Arrays.asList(cases.toArray());
+	}
+
+	@Parameterized.Parameter
+	public String type;
+
+	@Parameterized.Parameter(value = 1)
+	public Integer length;
+
+	@Before	@After
+	public void cleanup() {
+		System.clearProperty("thumbnailator.disableExifWorkaround");
+	}
+
+	@Test
+	public void terminatesProperlyWithWorkaround() {
+		runTest();
+	}
+
+	@Test
+	public void terminatesProperlyWithoutWorkaround() {
+		System.setProperty("thumbnailator.disableExifWorkaround", "true");
+		runTest();
+	}
+
+	/**
+	 * Test to check that reading an abnormal file won't cause image reading
+	 * to end up in a bad state like in an infinite loop.
+	 */
+	private void runTest() {
+		try {
+			byte[] bytes = new byte[length];
+			InputStream sourceIs = ClassLoader.getSystemResourceAsStream(String.format("Thumbnailator/grid.%s", type));
+			sourceIs.read(bytes);
+			sourceIs.close();
+
+			ByteArrayInputStream is = new ByteArrayInputStream(bytes);
+			InputStreamImageSource source = new InputStreamImageSource(is);
+
+			source.read();
+
+		} catch (Exception e) {
+			// terminates properly, even if an exception is thrown.
+		}
+	}
+}