SIGSEGV while finalizing MatOfRect (while GC)

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Hey guys, I'm using OpenCV4Android v.2.4.9 on Nexus 5 with android 4.4.4 stock rom.

I use this piece of code for running haar cascade face detection:

public Rect getFaceFromCascade(){
    // cascade! woohoo
    if (mFrontCascade != null) {
        int height = mWorkingFrame.rows();
        int faceSize = Math.round(height * mMinFaceSize);

        mFrontCascade.detectMultiScale(mWorkingFrame, mFaceList, 
                        1.1, 2, 2 , new Size(faceSize, faceSize), new Size());
    }

    Rect[] facesArray = mFaceList.toArray();

    if (facesArray.length == 0){
        //cascade couldn't find any face
        return null;
    }

    return facesArray[0];
}

mFaceList is a MatOfRect i'm creating once when the class is initialized.

When the class dies, I don't do anything with mFaceList (although i've also tried releasing it and that didn't help), and leave it to the garbage collector, but when the GC comes along later on, i get a SIGSEGV. After deep investigation i found the the problem is when release is called in the MatOfRect (Mat) finalizer.

When my class dies the mFaceList has the following header:

Mat [ 1*1*CV_32SC4, isCont=true, isSubmat=false, nativeObj=0x713cdad8, dataAddr=0x751badf0 ]

and in the finalize method of mFaceList it has the following header:

Mat [ 1964813884*1*CV_32SC(455), isCont=false, isSubmat=true, nativeObj=0x751ad8bc, dataAddr=0x751cae60 ]

That's when the SIGSEGV is occurring. any idea what can mess with the header like that? or why is this happening? I don't have any other references of this MatOfRect anywhere in the code.

Any help would be appreciated. Vlad