Fixed adding feeds with long filename

2 files changed, 44 insertions, 1 deletions

diff --git a/app/src/androidTest/java/de/test/antennapod/util/FilenameGeneratorTest.java b/app/src/androidTest/java/de/test/antennapod/util/FilenameGeneratorTest.java
index d33eb55b8..6f8042d61 100644
--- a/app/src/androidTest/java/de/test/antennapod/util/FilenameGeneratorTest.java
+++ b/app/src/androidTest/java/de/test/antennapod/util/FilenameGeneratorTest.java
@@ -9,11 +9,13 @@ import java.io.File;
 import java.io.IOException;
 
 import de.danoeh.antennapod.core.util.FileNameGenerator;
+import org.apache.commons.lang3.StringUtils;
 import org.junit.After;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
 
 @SmallTest
@@ -66,6 +68,23 @@ public class FilenameGeneratorTest {
         assertFalse(TextUtils.isEmpty(result));
     }
 
+    @Test
+    public void testLongFilename() throws IOException {
+        String longName = StringUtils.repeat("x", 20 + FileNameGenerator.MAX_FILENAME_LENGTH);
+        String result = FileNameGenerator.generateFileName(longName);
+        assertTrue(result.length() <= FileNameGenerator.MAX_FILENAME_LENGTH);
+        createFiles(result);
+    }
+
+    @Test
+    public void testLongFilenameNotEquals() {
+        // Verify that the name is not just trimmed and different suffixes end up with the same name
+        String longName = StringUtils.repeat("x", 20 + FileNameGenerator.MAX_FILENAME_LENGTH);
+        String result1 = FileNameGenerator.generateFileName(longName + "a");
+        String result2 = FileNameGenerator.generateFileName(longName + "b");
+        assertNotEquals(result1, result2);
+    }
+
     /**
      * Tests if files can be created.
      *
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/FileNameGenerator.java b/core/src/main/java/de/danoeh/antennapod/core/util/FileNameGenerator.java
index 5579ec27d..220a783f3 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/util/FileNameGenerator.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/FileNameGenerator.java
@@ -2,11 +2,18 @@ package de.danoeh.antennapod.core.util;
 
 import android.text.TextUtils;
 
+import androidx.annotation.VisibleForTesting;
 import org.apache.commons.lang3.ArrayUtils;
 
+import java.io.UnsupportedEncodingException;
+import java.security.NoSuchAlgorithmException;
+
 
 /** Generates valid filenames for a given string. */
 public class FileNameGenerator {
+    @VisibleForTesting
+    public static final int MAX_FILENAME_LENGTH = 255; // Limited by ext4
+    private static final int MD5_HEX_LENGTH = 32;
 
     private static final char[] validChars =
             ("abcdefghijklmnopqrstuvwxyz"
@@ -36,8 +43,11 @@ public class FileNameGenerator {
         String filename = buf.toString().trim();
         if (TextUtils.isEmpty(filename)) {
             return randomString(8);
+        } else if (filename.length() >= MAX_FILENAME_LENGTH) {
+            return filename.substring(0, MAX_FILENAME_LENGTH - MD5_HEX_LENGTH - 1) + "_" + md5(filename);
+        } else {
+            return filename;
         }
-        return filename;
     }
 
     private static String randomString(int length) {
@@ -47,4 +57,18 @@ public class FileNameGenerator {
         }
         return sb.toString();
     }
+
+    private static String md5(String md5) {
+        try {
+            java.security.MessageDigest md = java.security.MessageDigest.getInstance("MD5");
+            byte[] array = md.digest(md5.getBytes("UTF-8"));
+            StringBuilder sb = new StringBuilder();
+            for (byte b : array) {
+                sb.append(Integer.toHexString((b & 0xFF) | 0x100).substring(1, 3));
+            }
+            return sb.toString();
+        } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
+            return null;
+        }
+    }
 }