Why does resetting a 0x0 cell property value result in 0x1 cell?

I unfortunately cannot share the code, because it's confidential. I have tried to create a MWE, but it appears not to recreate the issue, which confuses me even more. I'm using MATLAB R2017b.

I have a class definition with a property that has as default value an empty cell, {}, which is more specifically a 0x0 empty cell array. The class has a reset method that simply resets the property value to the empty cell {}. However, if I create an object of the class and reset the object, the property value is set to the empty cell, good, but more specifically a 0×1 empty cell array, not good. If I now run unit testing functions, it tests whether two class objects are equal after one is reset, which is not true because isequal({}, cell(0,1)) returns false. This is the real problem. Also, it displays the value as {0×1 cell} instead of just {} which is plainly annoying.

As I said, I cannot recreate the issue in a MWE. I have tried searching MATLAB Answers, found nothing.

EDIT: I will still include the MWE so it's clear exactly what the workflow would be. Imagine the class definition is as follows:

classdef MyClass < handle
    
    properties
        Property1 = {};
    end
    
    methods
        function obj = MyClass
        end
        
        function reset(obj)
            obj.Property1 = {};
        end
    end
end

Then, I would run the code

obj = MyClass;
obj
obj.reset
obj

Then the output on the command window would be

obj = 

  MyClass with properties:

    Property1: {}


obj = 

  MyClass with properties:

    Property1: {0x1 cell}

Answer 1

[Steven H]

Turns out, there is a setter that forces the input to be a column vector by doing e.g.

c = {1, 2};
c(:)

To complete the MWE, add the set method

function set.Property1(obj, in)
    obj.Property1 = in(:);
end

and that's how the issue can be recreated. The solution is to check whether the input is empty or not before setting it like that.

Answer 2

[Jan]

If we cannot see the reset function, there is no chance, that we can guess, how the {0x1} cell is created.

You could add a test for empty cells, which set all empty cells to {0x0}:

if isempty(c)
   c = {};
end

[Steven H]

As I said, the issue is not recreated in a MWE so I don't know how that would be helpful. Though of course I understand that the only thing one can do is guess. I was hoping it's a known MATLAB bug to some people. For clarification, I'll add the MWE still.