MATLAB: Does MLint issue an inappropriate ‘might be growing inside a loop’ warning

Question

The MLint shows a 'might be growing inside a loop' warning when a finite string is concatenated with each line of a file when a loop is used to access the file line by line.

For example, if you type in the following

function lint_2007jul18(fIn, fOut)
while true
tline = fgets(fIn);
if tline == -1, break; end
if ~isempty(strfind(tline,'skip'))
tline = [ '%<skip> ' tline ];
end
fwrite(fOut,'%s', tline);
end
end

MLint shows a warning 'might be growing inside a loop'.

Answer 1

This is a known issue. Mlint runs a test to see if the variable is growing but its result is not guaranteed, which is why the warning says 'might be growing', not 'is growing'.