some tex files use a % before footnote?

Question

I simply can't understand the difference: in some of my tex files I see something like this:

some text with a footnote\footnote{some footnote}

while in other files i see:

some text with a footnote%
\footnote{some footnote%
}

Whils this seems to make absolutely no difference to output, it does mess things up for latexdiff when trying to compare two files. Can anyone explain why one is preferred over the other and a good way to reconcile things like this so it wouldn't show up as a difference in latexdiff. Also, what's the best way to get rid of the %, regex replace? (PS: I know that % is simply a comment and presumably does nothing when placed at the end of the line)

Answer 1

You can use perl in a terminal to delete % followed by a newline. Like this:

cat LaTeXfil1.tex | perl -p -i -e 's/%\n//g;'

So instead of

latexdiff LaTeXfil1.tex LaTeXfil2.tex

you should be able to use latexdiff like this:

latexdiff <(cat LaTeXfil1.tex | perl -p -i -e 's/%\n//g;') LaTeXfil2.tex 

I can not test it, as I do not know exactly what latexdiff does or what output is expected.