* doc/lispref/display.texi (Invisible Text): Document the return
value of 'invisible-p'.

* src/xdisp.c (Finvisible_p): Rename the argument POS.  Doc fix.
(Bug#29721)

* src/dispnew.c (check_glyph_memory): Remove no-longer-needed
check that Vframe_list is non-nil, as FOR_EACH_FRAME no longer
assumes that.

This cleans up a recent fix related to Bug#29661.
Suggested by Stefan Monnier in:
https://lists.gnu.org/r/emacs-devel/2017-12/msg00544.html
* src/frame.c (next_frame, prev_frame, delete_frame):
Restore debugging checks that Vframe_list is non-nil,
as FOR_EACH_FRAME no longer has these checks.
(delete_frame): Remove no-longer-needed checks that Vframe_list is
non-nil, as FOR_EACH_FRAME no longer assumes that.
* src/frame.h (FOR_EACH_FRAME): Do not assume Vframe_list is non-nil.

This does not fix Bug#29961 but avoids that Emacs segfaults when
trying to shut down because it lost connection to the X server.

* src/dispnew.c (check_glyph_memory):
* src/frame.c (delete_frame): Don't run FOR_EACH_FRAME when
there's no frame left (Bug#29961).

* src/buffer.c (Fbuffer_list): Fix doc-string.

* src/macfont.m (macfont_get_glyph_for_character):
(mac_font_get_glyphs_for_variants): Inline Objective-C blocks.

(cherry picked from commit 4590f1d768adbb2120a2b02c614f7ed3b21a4a3e)

* admin/unidata/IVD_Sequences.txt: New version from
http://www.unicode.org/ivd/, the 2017-12-12 version of the Unicode
Ideographic Variation Database.

* src/macuvs.h: Regenerated.

* src/fontset.c (free_realized_fontsets): Call
recompute_basic_faces, so that the basic faces are available to
any Lisp that calls this function, e.g. via set-fontset-font.
(Bug#29632)