+ 6.3 (Oct 21, 2021)
+ Interface changes:
+
+ + the definition of TERMTYPE2 is now internal, not visible in the ABI,
+ like the enclosing TERMINAL which was previously made opaque. This
+ was done to provide SCREEN-specific "static" variables in terminfo.
+
+ Added extensions:
+
+ + add sp-funcs for erasewchar, killwchar.
+
+ Added internal functions (other than "_sp" variants):
+
+ + _nc_safe_fopen and _nc_safe_open3 limit privileges if possible when
+ opening a file; otherwise disallow access for updating files.
+
+ + _nc_tiparm is a variant of tiparm which is used when all of the
+ parameters are known to be numbers rather than possibly strings.
+
+ + _nc_reset_tparm improves tic's checks by resetting the terminfo
+ "static variables" before calling functions which may update them.
+
+ Removed internal functions:
+
+ + none
+
+ Modified internal functions:
+
+ + _nc_trace_ttymode passes pointer to const data
+
+ + _nc_tparm_analyze passes pointer to int*, not int[]
+
+ 6.2 (Feb 12, 2020)
+ Interface changes:
+
+ + the terminal database must be compiled with ncurses 6.2 tic;
+ older versions of tic/infocmp will not work. Aside from that,
+ the compiled database will work with older applications.
+
+ + "*.pc" and "ncurses*-config" files give the same information.
+
+ + vwprintw and vwscanw are deprecated.
+
+ Added extensions:
+
+ + These make it simpler to substitute a debug-configuration of the
+ library for non-debug:
+ curses_trace
+ exit_curses
+ exit_terminfo
+
+ Added internal functions (other than "_sp" variants):
+
+ + These provide fast-lookup of common user-defined capabilities:
+ _nc_find_user_entry
+ _nc_get_userdefs_table
+ _nc_get_hash_user
+
+ + This is added to work around compiler-warnings:
+ _nc_fmt_funcptr
+
+ Removed internal functions:
+
+ + _nc_import_termtype
+
+ Modified internal functions:
+
+ + _nc_reserve_pairs no longer returns a value
+
+ 6.1 (Jan 27, 2018)
+ Interface changes:
+
+ + X/Open Curses specifies a "reserved" void* parameter in several
+ functions, saying that it must be NULL. In this release, if the
+ parameter is non-NULL, it is interpreted as a point to an integer
+ containing a color pair. In previous releases, a non-NULL parameter
+ caused an error return. Portable applications are unaffected. Here
+ are the functions which have been extended:
+ attr_get
+ attr_off
+ attr_on
+ attr_set
+ chgat
+ color_set
+ mvchgat
+ mvwchgat
+ slk_attr_off
+ slk_attr_on
+ slk_attr_set
+ wattr_get
+ wattr_on
+ wattr_off
+ wattr_set
+ wchgat
+ wcolor_set
+
+ + the TERMINAL structure declared in <term.h> has been made opaque,
+ and its size increased to handle the increased size of color pair
+ and color value, as well as other numeric capabilities.
+
+ A few applications required change, e.g., to use def_prog_mode;
+ only one application (tack) is known to have a valid reason for
+ accessing these internal details, and that was addressed by the
+ release of tack 1.08 in 2017. Internal functions marked as used
+ by tack will be deprecated in future releases.
+
+ Added extensions:
+
+ + Several new functions were added to manipulate extended color pairs
+ and color values. These include:
+ alloc_pair
+ extended_color_content
+ extended_pair_content
+ extended_slk_color
+ find_pair
+ free_pair
+ init_extended_color
+ init_extended_pair
+ reset_color_pairs
+
+ as well as corresponding sp-functions.
+
+ + A new terminfo capability "RGB" tells the ncurses library that the
+ color values are red/green/blue, to eliminate the need for palettes
+ in that special case for the color_content function.
+
+ Added internal functions (other than "_sp" variants):
+ _nc_copy_termtype2
+ _nc_export_termtype2
+ _nc_fallback2
+ _nc_find_prescr
+ _nc_forget_prescr
+ _nc_free_termtype2
+ _nc_read_entry2
+ _nc_write_object
+
+ Removed internal functions:
+ _nc_check_termtype
+ _nc_resolve_uses
+
+ Modified internal functions:
+
+ + symbols are used by tic/infocmp/toe:
+ _nc_align_termtype - change parameters to TERMTYPE2*
+ _nc_check_termtype2 - change parameter to TERMTYPE2*
+ _nc_read_file_entry - change parameter to TERMTYPE2*
+ _nc_read_termtype - change parameter to TERMTYPE2*
+ _nc_trim_sgr0 - change parameter to TERMTYPE2*
+ _nc_write_entry - change parameter to TERMTYPE2*
+
+ + symbols used only within the library:
+ _nc_fallback - change return type to TERMTYPE2*
+ _nc_init_termtype - change parameter to TERMTYPE2*
+
+ 6.0 (Aug 08, 2015)
+ Interface changes:
+
+ + The 6.0 ABI modifies the defaults for these configure options:
+ --enable-const
+ --enable-ext-colors
+ --enable-ext-mouse
+ --enable-ext-putwin
+ --enable-interop
+ --enable-lp64
+ --enable-sp-funcs
+ --with-chtype=uint32_t
+ --with-mmask_t=uint32_t
+ --with-tparm-arg=intptr_t
+
+ + ncurses supports symbol versioning. If you use this feature, about
+ half of the "_nc_" private symbols are changed to local symbols.
+
+ + a few applications may need to explicitly flush the standard output
+ when switching between printf's and (curses) printw.
+
+ Added extensions:
+
+ + use_tioctl is an improvement over use_env
+
+ + added wgetdelay to support the NCURSES_OPAQUE feature.
+
+ Added internal functions (other than "_sp" variants):
+ _nc_init_termtype
+ _nc_mvcur
+ _nc_putchar
+ _nc_setenv_num
+ _nc_trace_mmask_t
+
+ Removed internal functions:
+ none
+
+ Modified internal functions:
+ _nc_do_color - change parameters from short/bool to int
+ _nc_keypad - change parameter from bool to int
+ _nc_setupscreen - change parameter from bool to int
+ _nc_signal_handler - change parameter from bool to int
+
+ 5.9 (Apr 04, 2011)