COMPRESS-197: Tar file for Android backup cannot be read

Allow more than one or two NUL or space characters at the end of a field

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/compress/trunk@1369655 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/java/org/apache/commons/compress/archivers/tar/TarUtils.java b/src/main/java/org/apache/commons/compress/archivers/tar/TarUtils.java
index 4940d1d..0a38336 100644
--- a/src/main/java/org/apache/commons/compress/archivers/tar/TarUtils.java
+++ b/src/main/java/org/apache/commons/compress/archivers/tar/TarUtils.java
@@ -130,10 +130,11 @@
             throw new IllegalArgumentException(
                     exceptionMessage(buffer, offset, length, end-1, trailer));
         }
-        // May have additional NUL or space
-        trailer = buffer[end-1];
-        if (trailer == 0 || trailer == ' '){
+        // May have additional NULs or spaces
+        trailer = buffer[end - 1];
+        while (start < end - 1 && (trailer == 0 || trailer == ' ')) {
             end--;
+            trailer = buffer[end - 1];
         }
 
         for ( ;start < end; start++) {
diff --git a/src/test/java/org/apache/commons/compress/archivers/tar/TarArchiveInputStreamTest.java b/src/test/java/org/apache/commons/compress/archivers/tar/TarArchiveInputStreamTest.java
index 680cb8c..d76360f 100644
--- a/src/test/java/org/apache/commons/compress/archivers/tar/TarArchiveInputStreamTest.java
+++ b/src/test/java/org/apache/commons/compress/archivers/tar/TarArchiveInputStreamTest.java
@@ -20,10 +20,12 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.IOException;
 import java.net.URI;
 import java.net.URL;
 import java.util.Calendar;
@@ -120,4 +122,24 @@
         }
     }
 
-}
\ No newline at end of file
+    @Test
+    public void testCompress197() throws Exception {
+        TarArchiveInputStream tar = getTestStream("/COMPRESS-197.tar");
+        try {
+            TarArchiveEntry entry = tar.getNextTarEntry();
+            while (entry != null) {
+                entry = tar.getNextTarEntry();
+            }
+        } catch (IOException e) {
+            fail("COMPRESS-197: " + e.getMessage());
+        } finally {
+            tar.close();
+        }
+    }
+
+    private TarArchiveInputStream getTestStream(String name) {
+        return new TarArchiveInputStream(
+                TarArchiveInputStreamTest.class.getResourceAsStream(name));
+    }
+
+}
diff --git a/src/test/resources/COMPRESS-197.tar b/src/test/resources/COMPRESS-197.tar
new file mode 100644
index 0000000..2f42ee0
--- /dev/null
+++ b/src/test/resources/COMPRESS-197.tar
Binary files differ