In ArrayList class of java.util package I notice following lines of code

private Object[] grow(int minCapacity) {
    int oldCapacity = elementData.length;
    if (oldCapacity > 0 || elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA) {//Line3
        int newCapacity = ArraysSupport.newLength(oldCapacity,//Line 4
                minCapacity - oldCapacity, /* minimum growth */
                oldCapacity >> 1           /* preferred growth */);
        return elementData = Arrays.copyOf(elementData, newCapacity);
    } else {
        return elementData = new Object[Math.max(DEFAULT_CAPACITY, minCapacity)];
    }
}

In line 3 we have an if statement. The construct is such that else block is executed only when oldCapacity == 0 and elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA. Now, because of line 2 and condition that DEFAULTCAPACITY_EMPTY_ELEMENTDATA is private,static final oldCapacity == 0 is redundant. The entire piece of code can be simplified to

private Object[] grow(int minCapacity) {
    int oldCapacity = elementData.length;
    if (elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA) {
        int newCapacity = ArraysSupport.newLength(oldCapacity,
                minCapacity - oldCapacity, /* minimum growth */
                oldCapacity >> 1           /* preferred growth */);
        return elementData = Arrays.copyOf(elementData, newCapacity);
    } else {
        return elementData = new Object[Math.max(DEFAULT_CAPACITY, minCapacity)];
    }
}

is it a miss from developer or am I wrong somewhere?

I wanted to understand the usage of DEFAULTCAPACITY_EMPTY_ELEMENTDATA in ArrayList implementation. Since, it’s a widely used library I would expect it to have really efficient code. I don’t think there is anything wrong in my reasoning. If the community helps me we can make this library faster.