Custom clean filter goes into infinite loop while processing large files

[ssamirah]

Version

7.4.0.202509020913-r

Operating System

Windows

Bug description

My requirement is to create a custom filter where a particular file type extension is processed and the output is added to the repository.
I modified the git configuration to add custom filter and also appended the relevant extension to git attributes. My clean filter gets invoked however it goes into infinite loop.
I removed all logic for processing and just wrote the inputstream to the output, this also resulted in same behaviour. when I tried to read and write a small text file however it was successful. My simplified filter code which reads the inputstream and writes it to the output stream:

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.eclipse.jgit.attributes.FilterCommand;
import org.eclipse.jgit.attributes.FilterCommandFactory;
import org.eclipse.jgit.attributes.FilterCommandRegistry;
import org.eclipse.jgit.lib.Repository;

/**

• The Class CustomJgitCleanFilter.

*/
public class CustomJgitCleanFilter extends FilterCommand {

/** The Constant FACTORY. */
public static final FilterCommandFactory FACTORY = CustomJgitCleanFilter::new;
/**
 * Register.
 */
static void register() {
	FilterCommandRegistry.register("jgit://filter/purge/"
			+ org.eclipse.jgit.lib.Constants.ATTR_FILTER_TYPE_CLEAN, FACTORY);
}

/**
 * Instantiates a new scg jgit pre process filter.
 * @param db the db
 * @param in the in
 * @param out the out
 * @throws IOException Signals that an I/O exception has occurred.
 */
public CustomJgitCleanFilter( Repository db,InputStream in, OutputStream out) throws IOException {
	super(in, out);
}

/**
 * Run.
 * @return the int
 * @throws IOException Signals that an I/O exception has occurred.
 */
@Override
public int run() throws IOException {
	int bytesRead;
    int bigBufferSize = 8192; 
 byte[] bigBuffer = new byte[bigBufferSize];
		while ((bytesRead = this.in.read(bigBuffer)) != -1) {
			if(bytesRead>0) {
			this.out.write(bigBuffer, 0, bytesRead);
			}
		}
		return bytesRead;
	
}

}

Actual behavior

The issue seems to be from this piece of code in org.eclipse.jgit.treewalk.WorkingTreeIterator -
private static long computeLength(InputStream in) throws IOException {
// Since we only care about the length, use skip. The stream
// may be able to more efficiently wade through its data.
//
long length = 0;
for (;;) {
long n = in.skip(1 << 20);
if (n <= 0)
break;
length += n;
}
return length;
}
For smaller sized files this block is not invoked and gets processed, however for files larger than 65536 bytes this issue occurs, The issue is reproduceable with a simple zip file larger than 65536 bytes.**

Expected behavior

The process should end smoothly or in case of any exception should throw error instead of goin into an infinite loop.

Relevant log output

Other information

No response