bug#22104: 25.1.50; doc string of `modify-frame-parameters'

[Drew Adams]

This part of the doc string is unclear:

 Undefined PARMs are ignored, but stored in the frame's parameter list
 so that 'frame-parameters' will return them.

What does "ignored" mean here?  It can only mean (?) ignored by
`modify-parameters', but what does that mean, operationally?

The rest of the sentence would lead you to think that
`modify-parameters' nevertheless updates the parameter list for 
"ignored" parameters.  But then in what way are they ignored?




In GNU Emacs 25.1.50.1 (i686-pc-mingw32)
 of 2015-12-04
Bzr revision: ffefb6e899fbcdcbd79cb34292d57b7bc3043fcc
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --prefix=/c/Devel/emacs/snapshot/trunk --enable-checking=yes
 --enable-check-lisp-object-type --without-compress-install 'CFLAGS=-Og
 -ggdb3' LDFLAGS=-Lc:/Devel/emacs/lib 'CPPFLAGS=-DGC_MCHECK=1
 -Ic:/Devel/emacs/include''