A DESCRIPTION OF THE PROBLEM :
I'm trying the following Pattern:

Pattern p = Pattern.compile("^(\\d+)$");

Strangely, IMHO:

p.matcher("123\n").find() == true;
p.matcher("123\n").lookingAt() == true; // also weird
p.matcher("123\n\n").find() == false; // ok
p.matcher("123\na").find() == false; // also ok
p.matcher("123\n").matches() == false; // ok to me

Quoting the documentation for the "multiline flag" from the Javadocs:

"Enables multiline mode. In multiline mode the expressions ^ and $ match just after or just before, respectively, a line terminator or the end of the input sequence. By default these expressions only match at the beginning and the end of the entire input sequence."

Well, to me '\n' (i.e the new line character) is not the end of the input sequence, so '$' should only match it in multiline mode.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Just compile and execute the sample unit test I provided.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Look at the source code. I would expect all assertions to pass.
ACTUAL -
Look at the source code. The two first assertions fail.

---------- BEGIN SOURCE ----------
import org.junit.Test;
import java.util.regex.Pattern;
import static org.junit.Assert.assertFalse;

public class BugTest
{
    @Test
    public void testMe()
    {
        Pattern p = Pattern.compile("^(\\d+)$");

        assertFalse(p.matcher("123\n").find()); // this fails, but should not
        assertFalse(p.matcher("123\n").lookingAt()); // also fails
        assertFalse(p.matcher("123\n\n").find()); // ok
        assertFalse(p.matcher("123\na").find()); // also ok
        assertFalse(p.matcher("123\n").matches()); // ok to me
    }
}

---------- END SOURCE ----------

FREQUENCY : always