🚀 go-pugleaf

I know this isn't a Delphi problem, but maybe someone either knows the
answer, or has a workaround.

I am using Help&Manual to create my help files.

When I update my application, I may need to make a small change to the
help file, for example, I might change the text for one or two topics.

I then create a "patch file" for distribution. The patch file contains
the difference between the old and the new executable, and generally
is only a small file, typically 500K. As a comparison, the full setup
distribution is around 5MB.

I use InnoSetup for my install maker, and I use Clickteam PatchMaker
to generate the patch files.

Now, this has been working well when I was creating the old WinHelp
files. But now need to switch to CHM for Vista.

But, now that I have switched to the CHM format, PatchMaker is
generating a patch file around 3.5MB. In fact, almost the entire patch
file is now the new CHM file.
It would seem that the new CHM file is internally very different to
the older CHM file, even though I have only added one line of text to
one topic. It would seem that, at a binary level, almost the entire
file has had some change applied.

Is this how the CHM "compiler" works?
There are changes applied right through the file, rather than just in
one specific location?

-- 
Bob Small