What causes "No current tar entry" in MuntashirAkon/AppManager?

Call getNextTarEntry()/getNextEntry() and check for non-null before every read loop

MuntashirAkon/AppManager · error · IllegalStateException

No current tar entry

Error message

No current tar entry

What it means

Thrown by TarArchiveInputStream.read when there is no current entry to read from. Reading is positional: you must first advance the stream with getNextEntry/getNextTarEntry before calling read; otherwise the stream has no entry context.

Solutions

Call getNextTarEntry()/getNextEntry() and check for non-null before every read loop
Stop the read loop as soon as getNextEntry() returns null
Create a new TarArchiveInputStream instead of reusing an exhausted one
Guard reads with a currEntry != null check (which is what read() itself does internally)

Example fix

// before
TarArchiveEntry entry = tin.getNextTarEntry();
byte[] data = new byte[1024];
tin.read(data); // crashes if entry was null
// after
TarArchiveEntry entry = tin.getNextTarEntry();
if (entry != null) {
    byte[] data = new byte[1024];
    tin.read(data);
}

Defensive patterns

Strategy: validation

Validate before calling

TarArchiveEntry entry = tin.getNextTarEntry();
if (entry == null) { throw new IOException("no entry available to read"); }

Type guard

boolean hasCurrentEntry(TarArchiveInputStream in, TarArchiveEntry current) { return current != null; }

Try / catch

try {
    tin.read(buf, 0, buf.length);
} catch (IllegalStateException e) {
    if ("No current tar entry".equals(e.getMessage())) {
        throw new IOException("Call getNextTarEntry() before reading", e);
    }
    throw e;
}

Prevention

Always iterate with getNextTarEntry() and check for null before reading
Never reuse an exhausted TarArchiveInputStream
Structure read loops as: while ((e = in.getNextTarEntry()) != null) { readFully(e); }

When it happens

Trigger: Calling read(byte[],int,int) before the first getNextEntry() call, after getNextEntry() returned null (EOF), or after close() — e.g. in getLongNameData when the entry state was lost.

Common situations: Reading entries without iterating via getNextTarEntry; reusing a stream object after exhausting it; off-by-one loop conditions that read one extra time after null.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

AI-assisted analysis of MuntashirAkon/AppManager@0152f468fc (2026-09-12). Data as JSON: /api/errors/87644161ca6a3aae. Report an issue: GitHub.

Appendix: source

Thrown at app/src/main/java/org/apache/commons/compress/archivers/tar/TarArchiveInputStream.java:712

     * @param buf The buffer into which to place bytes read.
     * @param offset The offset at which to place bytes read.
     * @param numToRead The number of bytes to read.
     * @return The number of bytes read, or -1 at EOF.
     * @throws IOException on error
     */
    @Override
    public int read(final byte[] buf, final int offset, int numToRead) throws IOException {
        if (numToRead == 0) {
            return 0;
        }
    	int totalRead = 0;

        if (isAtEOF() || isDirectory()) {
            return -1;
        }

        if (currEntry == null) {
            throw new IllegalStateException("No current tar entry");
        }

        if (!currEntry.isSparse()) {
            if (entryOffset >= entrySize) {
                return -1;
            }
        } else {
            // for sparse entries, there are actually currEntry.getRealSize() bytes to read
            if (entryOffset >= currEntry.getRealSize()) {
                return -1;
            }
        }

        numToRead = Math.min(numToRead, available());

        if (currEntry.isSparse()) {
            // for sparse entries, we need to read them in another way
            totalRead = readSparse(buf, offset, numToRead);

View on GitHub (pinned to 0152f468fc)