BUG OF THE MONTH | Copy-Paste

V523 The ‘then’ statement is equivalent to the ‘else’ statement. matrix_type.cc 312

DEFUN(....)
{
  ....
  if (str_typ == "upper")
    mattyp.mark_as_permuted(len, p);
  else
    mattyp.mark_as_permuted(len, p); 
  ....    
}

There is no need to remind you that one should be very careful using the copy-paste technique when writing similarly looking constructs to avoid errors like this. It is doubtful that there should be two identical statements in the if-else block; a much more likely thing is that the mark_as_unpermuted method should be called when the else branch is triggered. Moreover, the programmer copied a part of code containing this buggy block to use in one more function later in the code, thus duplicating the error.

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