This patch takes only java into account.
I consider it ok if the first element is java or []
representing null in java.
I did not check the other cases
and thus this patch does not include documentation.

Add it if my fix is ok.
Please keep me informed.

My private tests (i am interested mostly in java)
are based on OctaveInterfaceTester i also provide.

my equality tests are also implemented in java.
I give you just the source:

   // the tests performed here, compare just java objects including null
    void testIsequal() {
        this.oct.eval("tester = javaObject(" + TESTER_NAME + ");");

        // tests including null
        this.oct.eval("b=isequal([], tester);");
        assertTrue(!this.oct.getBool("b"));
        this.oct.eval("b=isequal(tester, []);");
        assertTrue(!this.oct.getBool("b"));

        // test with different classes
        this.oct.eval("bd=javaObject('java.math.BigDecimal',4.2);");
        this.oct.eval("b=isequal(tester, bd);");
        assertTrue(!this.oct.getBool("b"));

        // tests with same classes but not equal
        this.oct.eval("bd1=javaObject('java.math.BigDecimal',4.2);");
        this.oct.eval("bd2=javaObject('java.math.BigDecimal',4.3);");
        this.oct.eval("b=isequal(bd1, bd2);");
        assertTrue(!this.oct.getBool("b"));

        // tests with same classes and equal
        this.oct.eval("bd1=javaObject('java.math.BigDecimal',4.2);");
        this.oct.eval("bd2=javaObject('java.math.BigDecimal',4.2);");
        this.oct.eval("b=isequal(bd1, bd2);");
        assertTrue(this.oct.getBool("b"));

        // tests including the tester: test of specific equals method
        this.oct.eval("t1 = javaObject(" + TESTER_NAME + ");");
        this.oct.eval("t2 = javaObject(" + TESTER_NAME + ");");
        this.oct.eval("b=isequal(t1, t2);");
        assertTrue(this.oct.getBool("b"));

        this.oct.eval("t1 = javaObject(" + TESTER_NAME + ");");
        this.oct.eval("t2 = javaObject(" + TESTER_NAME + ");");
        this.oct.eval("t1.bdVal = javaObject('java.math.BigDecimal',4.2);");
        this.oct.eval("b=isequal(t1, t2);");
        assertTrue(!this.oct.getBool("b"));

        this.oct.eval("t1 = javaObject(" + TESTER_NAME + ");");
        this.oct.eval("t2 = javaObject(" + TESTER_NAME + ");");
        this.oct.eval("t1.bVal = 42;");
        this.oct.eval("t1.bdVal = javaObject('java.math.BigDecimal',4.2);");
        this.oct.eval("t2.bVal = 42;");
        this.oct.eval("t2.bdVal = javaObject('java.math.BigDecimal',4.2);");
        this.oct.eval("b=isequal(t1, t2);");
        assertTrue(this.oct.getBool("b"));
    }

(file #38333, file #38334)