8302293: jar --create fails with IllegalArgumentException if archive name is shorter than 3 characters

Backport-of: bd0fde71d9113bad902e71b61f0ca44c650809ef

Author: Satyen Subramaniam

src/jdk.jartool/share/classes/sun/tools/jar/Main.java

@@ -323,11 +323,13 @@ public synchronized boolean run(String[] args) {
                     // error("Warning: -v option ignored");
                     vflag = false;
                 }
-                final String tmpbase = (fname == null)
+                String tmpFilePrefix = (fname == null)
                         ? "tmpjar"
                         : fname.substring(fname.indexOf(File.separatorChar) + 1);
-
-                tmpFile = createTemporaryFile(tmpbase, ".jar");
+                if (tmpFilePrefix.length() < 3) {
+                    tmpFilePrefix = "tmpjar" + tmpFilePrefix;
+                }
+                tmpFile = createTemporaryFile(tmpFilePrefix, ".jar");
                 try (OutputStream out = new FileOutputStream(tmpFile)) {
                     create(new BufferedOutputStream(out, 4096), manifest);
                 }
@@ -1745,11 +1747,12 @@ private File createTemporaryFile(String tmpbase, String suffix) {
             // Unable to create file due to permission violation or security exception
         }
         if (tmpfile == null) {
-            // Were unable to create temporary file, fall back to temporary file in the same folder
+            // We were unable to create temporary file, fall back to temporary file in the
+            // same folder as the JAR file
             if (fname != null) {
                 try {
                     File tmpfolder = new File(fname).getAbsoluteFile().getParentFile();
-                    tmpfile = File.createTempFile(fname, ".tmp" + suffix, tmpfolder);
+                    tmpfile = File.createTempFile(tmpbase, ".tmp" + suffix, tmpfolder);
                 } catch (IOException ioe) {
                     // Last option failed - fall gracefully
                     fatalError(ioe);

test/jdk/tools/jar/JarCreateFileNameTest.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.jar.JarFile;
+import java.util.spi.ToolProvider;
+import java.util.zip.ZipEntry;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+/*
+ * @test
+ * @bug 8302293
+ * @summary verify that a JAR file creation through "jar --create" operation
+ *          works fine if the JAR file name is less than 3 characters in length
+ * @run junit JarCreateFileNameTest
+ */
+public class JarCreateFileNameTest {
+
+    private static final ToolProvider JAR_TOOL = ToolProvider.findFirst("jar")
+            .orElseThrow(() ->
+                    new RuntimeException("jar tool not found")
+            );
+
+    /*
+     * Launches "jar --create --file" with file names of varying lengths and verifies
+     * that the JAR file was successfully created.
+     */
+    @ParameterizedTest
+    @ValueSource(strings = {"abcd", "abc", "ab", "a", "d.jar", "ef.jar"})
+    void testCreate(final String targetJarFileName) throws Exception {
+        final Path cwd = Path.of(".");
+        final Path tmpFile = Files.createTempFile(cwd, "8302293", ".txt");
+        final String fileName = tmpFile.getFileName().toString();
+        final int exitCode = JAR_TOOL.run(System.out, System.err,
+                "--create", "--file", targetJarFileName, fileName);
+        assertEquals(0, exitCode, "jar command failed");
+        // verify the JAR file is created and contains the expected entry
+        try (final JarFile jarFile = new JarFile(new File(targetJarFileName))) {
+            final ZipEntry entry = jarFile.getEntry(fileName);
+            assertNotNull(entry, "missing " + fileName + " entry in JAR file " + targetJarFileName);
+        }
+    }
+}
+