Stack usage

I have just discovered that
http://git.netsurf-browser.org/netsurf.git/tree/amiga/gui.c is using
~450K of stack space.

Visiting
http://libxad.cvs.sourceforge.net/viewvc/libxad/libxad/portable/clients/LhA.c?view=markup
uses just short of 1MB of stack.

I don't know about the second link, but I'm sure it wasn't that long
ago when the top link was viewable in 256K of stack or maybe even
128K.

I doubt much can be done about it, but am curious as to what has
changed to increase stack usage this much?

Whilst NetSurf is usually pretty good at not going mad with the stack
(it usually sits at <64K), suddenly using 1MB on certain pages seems a
bit excessive.

Chris