- a terminfo compiler tic(1), a decompiler infocmp(1), clear(1),
- tput(1), tset(1), and a termcap conversion tool captoinfo(1). Full
- manual pages are provided for the library and tools.
-
- The ncurses distribution is available via anonymous FTP at the GNU
- distribution site [1]ftp://ftp.gnu.org/gnu/ncurses/ .
- It is also available at [2]ftp://invisible-island.net/ncurses/ .
-
- Release Notes
-
- This release is designed to be upward compatible from ncurses 5.0
- through 5.4; very few applications will require recompilation,
- depending on the platform. These are the highlights from the
- change-log since ncurses 5.4 release.
-
- Interface changes:
- * terminfo installs "xterm-new" as "xterm" entry rather than
- "xterm-old" (aka xterm-r6).
- * terminfo data is installed using the tic -x option (few systems
- still use ncurses 4.2).
- * modify C++ binding to work with newer C++ compilers by providing
- initializers and using modern casts. Old-style header names are
- still used in this release to allow compiling with not-so-old
- compilers.
- * modify parameter type in c++ binding for insch() and mvwinsch() to
- be consistent with underlying ncurses library (was char, is
- chtype).
- * change NCursesWindow::err_handler() to a virtual function.
- * form and menu libraries now work with wide-character data.
- Applications which bypassed the form library and manipulated the
- FIELD.buf data directly will not work properly with libformw,
- since that no longer points to an array of char. The
- set_field_buffer() and field_buffer() functions translate to/from
- the actual field data.
- * add symbol to curses.h which can be used to suppress include of
- stdbool.h, e.g.,
- #define NCURSES_ENABLE_STDBOOL_H 0
- #include <curses.h>
-
- * change SP->_current_attr to a pointer, adjust ifdef's to ensure
- that libtinfo.so and libtinfow.so have the same ABI. The reason
- for this is that the corresponding data which belongs to the
- upper-level ncurses library has a different size in each model.
- * winnstr() now returns multibyte character strings for the
- wide-character configuration.
- * assume_default_colors() no longer requires that
- use_default_colors() be called first.
- * data_ahead() now works with wide-characters.
- * slk_set() and slk_wset() now accept and store multibyte or
- multicolumn characters.
- * start_color() now returns OK if colors have already been started.
- start_color() also returns ERR if it cannot allocate memory.
- * pair_content() now returns -1 for consistency with init_pair() if
- it corresponds to the default-color.
- * unctrl() now returns null if its parameter does not correspond to
- an unsigned char.
-
- New features and improvements:
- * library
- + environment variable NCURSES_NO_UTF8_ACS supports
- miscellaneous terminal emulators which ignore alternate
- character set escape sequences when in UTF-8 mode.
- + modify initialization of key lookup table so that if an
- extended capability (tic -x) string is defined, and its name
- begins with 'k', ncurses will automatically treat it as a
- key.
- + change GPM initialization, using dl library to load it
- dynamically at runtime.
- + form, menu and panel libraries support debug-tracing.
- * add NCURSES-Programming-HOWTO.html by Pradeep Padala (see
- http://tldp.org/HOWTO/NCURSES-Programming-HOWTO/).
- * programs:
- * infocmp:
- + The -i option now matches 8-bit controls against its table
- entries, e.g., so it can analyze the xterm-8bit entry.
- + add "-x" option to infocmp like tic's "-x", for use in "-F"
- comparisons. This modifies infocmp to only report extended
- capabilities if the -x option is given, making this more
- consistent with tic. Some scripts may break, since infocmp
- previous gave this information without an option.
- * tic:
- + modify termcap-parsing to retain 2-character aliases at the
- beginning of an entry if the "-x" option is used in tic.
- + filter out long extended names when translating to termcap
- format. Only two characters are permissible for termcap
- capability names.
- + correct translation of "%%" in terminfo format to termcap,
- e.g., using "tic -C".
- + modify the "-c -v" options to ignore delays when comparing
- strings. Also modify it to ignore a canceled sgr string,
- e.g., for terminals which cannot properly combine attributes
- in one control sequence.
- + add a check for improperly ended strings, i.e., where a
- following line begins in column 1.
- + add a check in tic for terminfo entries having an sgr0 but no
- sgr string. This confuses Tru64 and HPUX curses when combined
- with color, e.g., making them leave line-drawing characters
- in odd places.
- + add check (with debug configuration) that provides about the
- runtime changes that would be made to sgr0 for termcap
- applications.
- * tset:
- + add -c and -w options to allow user to suppress ncurses'
- resizing of the terminal emulator window in the special case
- where it is not able to detect the true size.
-
- Major bug fixes:
- * improve logic in tgetent() which adjusts the termcap "me" string
- to work with ISO-2022 string used in xterm-new. This is a feature
- that was incompletely implemented in ncurses 5.3. ncurses attempts
- to provide termcap clients with the portion of the sgr0 (termcap
- "me") string that does not reset line-drawing.
- * cells in the WINDOW which are continuations of a multicolumn
- character are encoded differently, making repainting more
- reliable.
- * amend change to setupterm() in ncurses 5.4 (20030405) which would
- reuse the value of cur_term if the same output was selected. This
- now reuses it only when setupterm() is called from tgetent(),
- which has no notion of separate SCREENs. Note that tgetent() must
- be called after initscr() or newterm() to use this feature.
- * make setcchar() now works when its wchar_t* parameter is pointing
- to a string which contains more data than can be converted.
- * win_wchnstr() now works for more than one cell.
- * resizeterm() now processes all levels of window hierarchy.
- * disable GPM mouse support when $TERM happens to be prefixed with
- "xterm". Gpm_Open() would otherwise assert that it can deal with
- mouse events in this case.
- * add SP->_screen_acs_map[], used to ensure that mapping of missing
- line-drawing characters is handled properly. For example,
- ACS_DARROW is absent from xterm-new, and it was coincidentally
- displayed the same as ACS_BTEE.
-
- Portability:
- * configure script:
- + new options:
-
- --enable-largefile
- set compiler and linker flags to use largefile
- support.
-
- --enable-ext-colors
- Allow encoding of 256 foreground and background
- colors, e.g., with the xterm-256color or
- xterm-88color terminfo entries. This requires ABI 6
- because it changes the size of cchar_t.
-
- --enable-ext-mouse
- This defines NCURSES_MOUSE_VERSION 2, and modifies
- the encoding of mouse events to support wheel mice,
- which may transmit buttons 4 and 5. This works with
- xterm and similar terminal emulators. This requires
- ABI 6 because it changes the encoding of mouse
- events.
-
- --with-chtype
- overriding of the non-LP64 model's use of chtype
-
- --with-mmask-t
- overriding of the non-LP64 model's use of mmask_t
-
- --without-xterm-new
- Installs "xterm-old" as the "xterm" entry of the
- terminfo database.
-
- + The --with-termlib option now accepts a value which sets the
- name of the terminfo library. This would allow a packager to
- build libtinfow.so renamed to coincide with libtinfo.so
- + fixes/improvements for cross-compiling:
- o suppress $suffix in misc/run_tic.sh when
- cross-compiling. This allows cross-compiles to use the
- host's tic program to handle the "make install.data"
- step.
- o correct BUILD_CPPFLAGS substitution in
- ncurses/Makefile.in, to allow cross-compiling from a
- separate directory tree.
- * library:
- + add ifdef's for _LP64 in curses.h to avoid using wasteful
- 64-bits for chtype and mmask_t, but add configure option
- --disable-lp64 in case anyone used that configuration.
- + modify C++ binding to use some C internal functions to make
- it compile properly on Solaris (and other platforms).
- + remove check in newwin() that prevents allocating windows
- that extend beyond the screen (Solaris does this).
- + check for nl_langinfo(CODESET), use it if available. This
- replaces ad hoc tests of environment variables to check if
- the terminal is setup for UTF-8 encoding. Applications which
- do not call setlocale() should be corrected, to make them
- work properly with UTF-8 encoding.
- In particular, applications which assume (and do not call
- setlocale()) that Latin-1 codes are printable will no longer
- work in a UTF-8 locale since the ad hoc check of environment
- variables to see if the locale was UTF-8 is not used when
- nl_langinfo(CODESET) is available.
- + use setlocale() to query the program's current locale rather
- than using getenv(). This supports applications which rely
- upon legacy treatment of 8-bit characters when the locale is
- not initialized.
-
- Features of Ncurses
-
- The ncurses package is fully compatible with SVr4 (System V Release 4)
- curses:
- * All 257 of the SVr4 calls have been implemented (and are
- documented).
- * Full support for SVr4 curses features including keyboard mapping,
- color, forms-drawing with ACS characters, and automatic
- recognition of keypad and function keys.
- * An emulation of the SVr4 panels library, supporting a stack of
- windows with backing store, is included.
- * An emulation of the SVr4 menus library, supporting a uniform but
- flexible interface for menu programming, is included.
- * An emulation of the SVr4 form library, supporting data collection
- through on-screen forms, is included.
- * Binary terminfo entries generated by the ncurses tic(1)
- implementation are bit-for-bit-compatible with the entry format
- SVr4 curses uses.
- * The utilities have options to allow you to filter terminfo entries
- for use with less capable curses/terminfo versions such as the
- HP/UX and AIX ports.
+ * captoinfo, a termcap conversion tool
+ * clear, utility for clearing the screen
+ * infocmp, the terminfo decompiler
+ * tabs, set tabs on a terminal
+ * tic, the terminfo compiler
+ * toe, list (table of) terminfo entries
+ * tput, utility for retrieving terminal capabilities in shell
+ scripts
+ * tset, to initialize the terminal
+
+ Full manual pages are provided for the library and tools.
+
+ The ncurses distribution is available at ncurses' homepage:
+
+ ftp://ftp.invisible-island.net/ncurses/ or
+ https://invisible-mirror.net/archives/ncurses/ .
+
+ It is also available via anonymous FTP at the GNU distribution site
+
+ ftp://ftp.gnu.org/gnu/ncurses/ .
+
+Release Notes
+
+ These notes are for ncurses 6.2, released February 12, 2020.
+
+ This release is designed to be source-compatible with ncurses 5.0
+ through 6.1; providing extensions to the application binary interface
+ (ABI). Although the source can still be configured to support the
+ ncurses 5 ABI, the reason for the release is to reflect improvements
+ to the ncurses 6 ABI and the supporting utility programs.
+
+ There are, of course, numerous other improvements, listed in this
+ announcement.
+
+ The most important bug-fixes/improvements dealt with user-defined
+ capabilities in terminal descriptions. The release notes also mention
+ some other bug-fixes, but are focused on new features and improvements
+ to existing features since ncurses 6.1 release.
+
+ Library improvements
+
+ New features
+
+ There are several new features:
+ * O_EDGE_INSERT_STAY tells the form library to optionally delay
+ cursor movement on a field edge/boundary
+ * O_INPUT_FIELD extension to form library allows a dynamic field to
+ shrink if the new limit is smaller than the current field size.
+ * added exit_curses and exit_terminfo to replace internal symbols
+ for leak-checking.
+ * added curses_trace, to replace trace().
+
+ Additionally, to improve performance other changes (and extensions)
+ are provided in this release:
+ * mouse decoding now handles shift/control/alt logic when decoding
+ xterm's 1006 mode
+ * ncurses now defines a limit for wgetnstr, wgetn_wstr when length
+ is negative or "too large".
+ * reordered loop-limit checks in winsnstr in case the string has no
+ terminating null and only the number of characters is used.
+ * there is now no buffer-size limit when reading the $TERMCAP
+ variable.
+ * the $TERMCAP variable may be interpreted as a fallback to a
+ terminfo entry
+ * mvcur now decides whether to use hard-tabs, using xt, tbc and hts
+ as clues.
+ * extended colors are improved by modifying an internal call to
+ vid_puts to pass extended color pairs e.g., from tty_update.c and
+ lib_mvcur.c
+ * the initialization functions now avoid relying upon persistent
+ data for the result from getenv
+ * scrolling is improved:
+ + a limit check in newline_forces_scroll handles the case where
+ the row is inside scroll-margins, but not at the end.
+ + improved loop limits in _nc_scroll_window handle a case where
+ the scrolled data is a pad which is taller than the window.
+
+ Other improvements
+
+ These are revised features:
+ * used "const" in some prototypes rather than NCURSES_CONST where
+ X/Open Curses was updated to do this, e.g., wscanw, newterm, the
+ terminfo interface. Also use "const" for consistency in the
+ termcap interface, which was withdrawn by X/Open Curses in Issue 5
+ (2007). As of Issue 7, X/Open Curses still lacks "const" for
+ certain return values, e.g., keyname.
+ * modified wbkgd and wbkgrnd to improve compatibility with SVr4
+ curses, changing the way the window rendition is updated when the
+ background character is modified
+ * improved terminfo write/read by modifying the fourth item of the
+ extended header to denote the number of valid strings in the
+ extended string table (see term(5)).
+ * modified the initialization checks for mouse so that the
+ xterm+sm+1006 block will work with terminal descriptions not
+ mentioning xterm.
+
+ These were done to limit or ultimately deprecate features:
+ * deprecated safe-sprintf, since the vsnprintf function, which does
+ what was needed, was standardized long ago.
+ * marked vwprintw and vwscanw as deprecated; recommend using
+ vw_printw and vw_scanw, respectively.
+ * added deprecation warnings for internal functions called by older
+ versions of tack.
+ * removed unused _nc_import_termtype2 function.
+
+ These are improvements to existing features:
+ * check parameter of set_escdelay, return ERR if negative.
+ * check parameter of set_tabsize, return ERR if not greater than
+ zero
+ * correct a status-check in _nc_read_tic_entry() so that if reading
+ a hex/b64 $TERMINFO, and the $TERM does not match, fall-through to
+ the compiled-in search list.
+ * amend check for repeat_char to handle a case where setlocale() was
+ called after initscr
+ * move macro for is_linetouched inside NCURSES_NOMACROS ifndef.
+ * use _nc_copy_termtype2 rather than direct assignment in setupterm,
+ in case it is called repeatedly using fallback terminfo
+ descriptions
+ * improve workaround for Solaris wcwidth versus line-drawing
+ characters
+ * add checks in repair_subwindows to keep the current position and
+ scroll-margins inside the resized subwindow.
+ * correct a buffer-limit in write_entry.c for systems that use
+ caseless filenames.
+ * improved build-time utility report_offsets:
+ + add categories, e.g., "w" for wide-character, "t" for threads
+ to make the report more readable. Reorganized the structures
+ reported to make the categories more apparent.
+ + add NCURSES_GLOBALS and NCURSES_PRESCREEN to report to show
+ how similar the different libtinfo configurations are.
+ * modified some header files to ensure that those include necessary
+ files except for the previously-documented cases
+ * added some traces in initialization to show whether a fallback
+ entry is used.
+ * made minor optimization to reduce calls to _nc_reserve_pairs
+
+ These are corrections to existing features:
+ * fix a special case in PutAttrChar where a cell is marked as
+ alternate-character set, but the terminal does not actually
+ support the given graphic character. This would happen in an older
+ terminal such as vt52, which lacks most line-drawing capability.
+ * corrected flag for "seq" method of db 1.8.5 interface, needed by
+ toe on some of the BSDs.
+ * modify comparison in make_hash.c to correct a special case in
+ collision handling for Caps-hpux11
+ * add extended_slk_color{,_sp} symbols to the appropriate
+ package/*.{map,sym} files
+ * modify lib_setup to avoid calling pthread_self() without first
+ verifying that the address is valid, i.e., for weak symbols
+ * add a couple of broken-linker symbols to the list of versioned
+ symbols to help with link-time optimization versus weak symbols.
+
+ Program improvements
+
+ Several improvements were made to the utility programs:
+
+ clear
+
+ + improved logic for clearing with the E3 extension, in case
+ the terminal scrolls content onto its saved-lines before
+ actually clearing the display, by clearing the saved-lines
+ after clearing the display
+
+ infocmp
+
+ + omit filtering of "OTxx" names which are used for obsolete
+ capabilities, when the output is sorted by long-names. This
+ change helps when making a table of the short/long capability
+ names.
+
+ tic
+
+ + added check for consistent alternate character set
+ capabilities.
+ + added check for paired indn/rin.
+ + added check for terminals with parm_dch vs parm_ich.
+ + added check for the case where setf/setb are given using
+ different strings, but provide identical results to
+ setaf/setab.
+ + corrected check for ich1.
+ + changed a too-large terminal entry from a fatal error to a
+ warning.
+
+ toe
+
+ + ignores any hex/b64 $TERMINFO value in the list of terminfo
+ databases.
+
+ tset
+
+ + replace check in reset command for obsolete "pt" capability
+ using tbc and hts capabilities as clues
+ + modify reset to allow for tabstops at intervals other than 8.
+ + change reset's behavior for margins to simply clear
+ soft-margins if possible, rather than clearing and then
+ setting them according to the terminal's width.
+
+ tput
+
+ + add "x" to getopt string so that "tput -x clear" works.
+
+ Several changes were made to the generated ncurses*config scripts and
+ the analogous ".pc" files to reduce differences between the
+ configurations they report:
+ * modified the ncurse*-config and pc-files to more closely match for
+ the -I and -l options.
+ * filtered out linker-specs from the --libs report.
+ * amended the ncurses*-config and pc-files to take into account the
+ rpath hack which differed between those files.
+ * modified generated ncurses*config and ncurses.pc, ncursesw.pc,
+ etc., to list helper libraries such as gpm for static linking.
+
+ Examples
+
+ Along with the library and utilities, improvements were made to the
+ ncurses-examples. Most of this activity aimed at improving the
+ test-packages. A few changes are more generally useful, e.g., for the
+ main ncurses test-program, and for analyzing traces using the
+ tracemunch script:
+ * improve recovery from error when reading command-character in
+ test/ncurses.c, showing the relevant error message and not exiting
+ on EINTR.
+ * improve tracemunch, by keeping track of TERMINAL* values, and if
+ tracing was first turned on after initialization, attempt to show
+ distinct screen, window and terminal names anyway.
+ * modify tracemunch to accept filename parameters in addition to use
+ as a pipe/filter.
+ * update tracemunch to work with perl 5.26.2, which changed the
+ rules for escaping regular expressions.
+ * add some checks in tracemunch for undefined variables.
+ * modify TurnOn/TurnOff macros (in lib_vidattr.c and lib_vid_attr.c)
+ to avoid expansion of "CUR" in trace.
+
+ There are other new demo/test programs and reusable examples:
+
+ color_content
+ Demonstrate the color_content and extended_color_content
+ functions.
+
+ demo_tabs
+ A simple demo of tabs in curses.
+
+ dump_window
+ A portable curses screen-dump, used to compare ncurses screen
+ contents with Solaris.
+
+ pair_content
+ Demonstrate the pair_content and extended_pair_content
+ functions.
+
+ report_hashing
+ Check hash-tables used for terminfo and termcap names.
+
+ parse_rgb
+ Sample implementation of the ncurses RGB extension from
+ user_caps.5, used in picsmap and savescreen programs.
+
+ A variety of improvements were made to existing programs, both new
+ features as well as options added to make the set of programs more
+ consistent.
+ * add "-l" option to test/background, to dump screen contents in a
+ form that lets different curses implementations be compared.
+ * add "@" command to test/ncurses F-test, to allow rapid jump to
+ different character pages.
+ * added enum, regex examples to test/demo_forms
+ * amend Scaled256() macro in test/picsmap.c to cover the full range
+ 0..1000
+ * corrected pathname used in Ada95 sample programs for explain.txt,
+ to work with test-packages, and used an awk script to split the
+ resulting pathname when it would be too long for a single line.
+ * ignore interrupted system-call in test/ncurses's command-line,
+ e.g., if the terminal were resized.
+ * improved ifdef's for TABSIZE variable, to help with AIX/HPUX
+ ports.
+
+ Terminal database
+
+ There are several new terminal descriptions:
+
+ alacritty, domterm, kitty, mintty, mintty-direct, ms-terminal,
+ n7900, nsterm-build309, nsterm-direct, screen5, ti703, ti707,
+ ti703-w, ti707-w vscode, vscode-direct, xterm-mono, xterm.js
+
+ There are many changes to existing terminal descriptions. Some were
+ updates to several descriptions:
+ * use ansi+rep in a dozen places
+ * add rs1 to konsole, mlterm
+ * improve several flash capabilities with trailing mandatory delays
+ * drop ich1 from rxvt-basic, Eterm and mlterm to improve
+ compatibility with old non-curses programs
+ * add/use xterm+keypad in xterm-new
+ * use xterm+sl-twm for consistency, nine places
+ * improve xm example in xterm+x11mouse and xterm+sm_1006.
+
+ while others affected specific descriptions. These were retested, to
+ take into account changes by their developers:
+
+ terminator, st
+
+ while these are specific fixes based on reviewing documentation, user
+ reports, or warnings from tic:
+
+ adds200:
+
+ + fix typo
+
+ gnome-256color
+
+ + base entry on "gnome", not "vte", for consistency
+
+ interix
+
+ + trim unnecessary setf/setb
+
+ linux-16color
+
+ + accommodate Linux console driver incompatibility introduced
+ in early 2018
+
+ nsterm-256color:
+
+ + add nsterm-build309 to replace nsterm-256color, assigning the
+ latter as an alias of nsterm, to make mouse work with
+ nsterm-256color
+
+ regent40:
+
+ + renumber function-keys to match manual
+
+ regent60:
+
+ + add cd (clr_eos)
+ + corrected acsc
+ + add shifted function-keys
+
+ tvi950:
+
+ + added function-key definitions to agree with Televideo 950
+ manual
+ + corrected acsc
+ + remove bogus kf0
+ + add bel
+
+ tvi955:
+
+ + fix typo
+
+ vi200:
+
+ + add acsc string, including right/down-arrow
+
+ wy50:
+
+ + corrected acsc
+
+ wy50 and wy60:
+
+ + add shifted function-keys as kF1 to kF16
+
+ xterm+x11hilite:
+
+ + eliminate unused p5 parameter.
+
+ A few entries use extensions (user-defined terminal capabilities):
+ * use xterm+sm+1006 (aka "SGR 1006 mouse") for konsole-base and
+ putty
+ * add Smol/Rmol user-defined capability to tmux and vte-2018
+ * add Smulx user-defined capability to tmux, vte-2018
+
+ Documentation
+
+ As usual, this release
+ * improves documentation by describing new features,
+ * attempts to improve the description of features which users have
+ found confusing
+ * fills in overlooked descriptions of features which were described
+ in the NEWS file but treated sketchily in manual pages.
+
+ In addition to providing background information to explain these
+ features and show how they evolved, there are corrections,
+ clarifications, etc.:
+ * Corrections:
+ + correct error-returns listed in manual pages for a few form
+ functions
+ + corrected prototypes in several manpages using script to
+ extract those in compilable form.
+ + fix typo in term.5, improve explanation of format
+ * Clarify in manual pages that vwprintw and vwscanw are obsolete.
+ They have not been part of X/Open Curses since 2007.
+ * New/improved history and portability sections:
+ + curs_addch.3x gives some background for ACS symbols.
+ + curs_getcchar.3x explains a difference between ncurses and
+ X/Open Curses.
+ + curs_getstr.3x gives historical/portability background for
+ the length parameter of wgetnstr.
+ + curs_slk.3x lists a few differences between SVr4 curses and
+ X/Open Curses for soft-keys.
+ + curs_terminfo.3x explains that the initial implementation of
+ terminfo in SVr2 was mostly replaced by other developers in
+ SVr3.
+ + infocmp.1 explains that the initial version of terminfo had
+ no tool for decompiling descriptions. That came later, with
+ SVr3, with a different developer.
+ + tabs.1 tells more than you wanted to know about the tool.
+ + tic.1 explains that the initial version of terminfo had a
+ rudimentary tool (based on termcap) for compiling entries.
+ The tool used with Unix was developed by others for SVr3.
+ + toe.1 explains the origin of this tool.
+ * Improvements for user_caps.5:
+ + mention meml, memu and box1
+ + expanded description of XM
+ + add a clarification regarding the RGB capability.
+ + mention user_caps.5 in the tic and infocmp manual pages.
+ * Other improvements:
+ + curs_add_wch.3x adds note about Unicode terminology for the
+ line-drawing characters.
+ + curs_color.3x improves discussion of error returns and
+ extensions.
+ + curs_mouse.3x explains how the kmous and XM capabilities are
+ used for xterm-mouse input.
+ + curs_refresh.3x improves documentation regarding the virtual
+ and physical screens.
+ + curs_util.3x mentions a difference between SVr4 and X/Open
+ Curses for unctrl.h
+ + curs_variables.3x improves description of the init_tabs
+ capability and TABSIZE variable.
+ + ncurses.3x improves documentation regarding feature-test
+ macros in curses.h
+ + resizeterm.3x about top-level windows which touch the
+ screen's borders.
+ + tput.1 clarifies how tput determines the terminal size.
+
+ There are no new manual pages (all of the manual page updates are to
+ existing pages).
+
+ Some of the improvements are more subtle, relating to the way the
+ information is presented. For instance, the generated terminfo.5 file
+ uses a different table layout, allowing it to use space on wide
+ terminals more effectively.
+
+ Interesting bug-fixes
+
+ While there were many bugs fixed during development of ncurses 6.2,
+ only a few (the reason for this release) were both important and
+ interesting. Most of the bug-fixes were for local issues which did not
+ affect compatibility across releases. Since those are detailed in the
+ NEWS file no elaboration is needed here.
+
+ The interesting bugs were in tic/infocmp's handling of user-defined
+ capabilities. These were not recent bugs. Initially it was a simple
+ problem:
+ * The user-defined capabilities can be any type (boolean, number or
+ string), but once given a type all uses of the name must conform
+ to that type--unless some special support for a particular
+ multi-typed name is built into ncurses.
+ * One of simpleterm's contributors copied some definitions for using
+ tmux's user-defined capabilities in late in 2016.
+
+diff --git a/st.info b/st.info
+@@ -185,7 +185,10 @@ st| simpleterm,
+ tsl=\E]0;,
+ xenl,
+ vpa=\E[%i%p1%dd,
+-
++# Tmux unofficial extensions, see TERMINFO EXTENSIONS in tmux(1)
++ Se,
++ Ss,
++ Tc,
+
+ st-256color| simpleterm with 256 colors,
+ use=st,
+
+ * Later, in (referring to a version from mid-2017), a user asked to
+ have it updated in ncurses.
+ * However, it had an error from the change in late 2016. The
+ terminal description made what tmux expected to be string actually
+ a boolean.
+ Over the years, there were problems with each of simpleterm's
+ terminal descriptions. I repaired those, and usually dealt with
+ the problem.
+ * The difference in this case was that when compiling the terminal
+ database, tic may have in memory the definitions for more than one
+ terminal description (so that it can resolve "use=" clauses).
+ Seeing two different types for the same name, in certain
+ situations it would incorrectly merge the symbol tables for the
+ two terminal descriptions.
+ * On simpleterm's side, their bug was finally fixed in late 2019,
+ three years after the bug was created.
+
+ For ncurses, the elapsed time to fix this bug was less than three
+ years. Someone reported a problem with the terminal description a few
+ weeks after releasing ncurses 6.1 (in tmux #1264), and the terminal
+ description was updated that week (ncurses patch 20180224):
+
+20180224
+ + modify _nc_resolve_uses2() to detect incompatible types when merging
+ a "use=" clause of extended capabilities. The problem was seen in a
+ defective terminfo integrated from simpleterm sources in 20171111,
+ compounded by repair in 20180121.
+ + correct Ss/Ms interchange in st-0.7 entry (tmux #1264) -TD
+
+ The larger part of that change added a check to prevent a simple merge
+ of terminal descriptions where the same user-defined name was used
+ with different types. But it raised some questions:
+ * Was there a reliable way to manage terminal descriptions which
+ used the same extended name in different ways?
+ * Should ncurses provide a registry of well-known extended names,
+ with their types?
+
+ Since the correction to terminfo.src could have been readily adopted
+ by packagers, there was nothing more to be done from ncurses'
+ standpoint on that part. But improving ncurses to prevent issues like
+ that is the reason for making a release.
+
+ Nothing more (constructive) was mentioned with regard to simpleterm.
+ But a few problems were found in the handling of user-defined
+ capabilities:
+ * Forward-references to user-defined capabilities in a "use=" clause
+ did not allocate new data for each use. In tic, successive
+ compilation of terminal entries could add user-defined
+ capabilities to the wrong terminal entry.
+ This was not noticed before, since xterm's terminal descriptions
+ were the main users of the feature, and almost all of the uses of
+ the building-blocks which contained user-defined capabilities were
+ backward-references.
+ * There is one (documented) case where ncurses 6.1 supports a
+ user-defined capability that could be any type (i.e., "RGB"). The
+ check added in February 2018 to guard against mismatches did not
+ handle all of the combinations needed.
+
+ Both of these issues dated from the original implementation of
+ user-defined capabilities. Fixing them does not change the terminal
+ database, but a older tic without the fixes will not be able to handle
+ terminfo sources which rely upon those fixes. Starting in June 2019,
+ the download link for the terminfo source file was capped at that
+ date. The development sources have an up-to-date copy of the file, for
+ people with a legitimate need for it.
+
+ The "-c" (check) option of tic is not very useful if it cannot offer
+ advice on parameters needed for user-defined capabilities. The various
+ Caps files were reorganized to reduce redundancy, and in the common
+ portion (Caps-ncurses), a registry of user-defined capabilities is
+ provided for use by tic. While users can still define their own custom
+ capabilities, tic will not offer any advice when their parameters do
+ not match.
+
+ In ncurses 6.2, tic makes a special check to allow any type for RGB,
+ but its being able to do this relies upon fixes made in the ncurses
+ library in mid-2019.
+
+ Configuration changes
+
+ Major changes
+
+ There are no major changes. Several new options were added to ease
+ integration of packages with systems using different versions of GNAT
+ and ncurses. Also, improvements were made to configure checks.
+
+ Configuration options
+
+ There are a few new/modified configure options:
+
+ --with-config-suffix
+ helps work around a filename conflict with Debian packages
+ versus test-packages.
+
+ --with-ada-libname
+ allows one to rename the "AdaCurses" library (at least one
+ packager prefers a lowercase name).
+
+ --with-fallbacks
+ now ensures there is a value, and adds the fallback information
+ to top-level Makefile summary.
+
+ --with-pcre2
+ check for pcre-posix library to help with MinGW port.
+
+ --with-tic-path and
+
+ --with-infocmp-path
+ help work around problems building fallback source using
+ pre-6.0 tic/infocmp.
+
+ --with-versioned-syms
+ option value can now be a relative pathname.
+
+ Portability
+
+ Many of the portability changes are implemented via the configure
+ script:
+ * ignore $TERMINFO as a default value in configure script if it came
+ from the infocmp -Q option.
+ * distinguish gcc from icc and clang when the --enable-warnings
+ option is not used, to avoid unnecessary warnings about
+ unrecognized inline options
+ * consistently prepend new libraries as they are found during
+ configuration, rather than relying upon the linker to resolve
+ order dependencies of libraries.
+ * modified configure scripts to reduce relinking/ranlib during
+ library install :
+ + use "install -p" when available, to avoid need for ranlib of
+ static libraries.
+ + scripts which use "--disable-relink;" add a 1-second sleep to
+ work around tools which use whole-second timestamps, e.g., in
+ utime rather than the actual file system resolution.
+ * add configure check for getenv to work around implementation shown
+ in Emscripten which overwrites the previous return value on each
+ call.
+ Use that to optionally suppress START_TRACE macro, whose call to
+ getenv may not work properly
+ * change target configure level for _XOPEN_SOURCE to 600 to address
+ use of vsscanf and setenv.
+ * reduce use of _GNU_SOURCE for current glibc where _DEFAULT_SOURCE
+ combines with _XOPEN_SOURCE
+ Allow for Cygwin's newlib when checking for the _DEFAULT_SOURCE
+ symbol.
+ MidnightBSD is now checked for the _XOPEN_SOURCE-related
+ definitions.
+ * If the check for va_copy or __va_copy fails,
+ + configure now tries copying the pointers for va_list, or as
+ an array.
+ + alternatively, it checks for __builtin_va_copy(), which could
+ be used with AIX xlc in c89 mode.
+ * several changes to support a port to Ultrix 3.1:
+ + check if "b" binary feature of fopen works
+ + check for missing feature of locale.h
+ + add fallback for strstr() in test-programs
+ + add fallback for STDOUT_FILENO in test-programs
+ * The test/configure script (used for ncurses-examples) is improved:
+ + work around non-ncurses termcap.h file, e.g., in Slackware.
+ + check for TABSIZE variable.
+ + checks for the X11/Intrinsic.h header, accommodate recent
+ MacOS changes which largely emptied /usr/include.
+
+ Here are some of the other portability fixes:
+ * added dummy "check" rule in top-level and test-Makefile to
+ simplify building test-packages for ArchLinux.
+ * dropped library-dependency on psapi for MinGW port, since
+ win_driver.c defines PSAPI_VERSION to 2, making it use
+ GetProcessImageFileName from kernel32.dll
+ * made build-fixes for configuration using --program-suffix with
+ Ada95, noticed with MacOS but applicable to other platforms
+ without libpanelw, etc.
+ * modified ncurses/Makefile.in to fix a case where Debian/testing
+ changes to the ld --as-needed configuration broke ncurses-examples
+ test packages.
+ * used _WIN32/_WIN64 in preference to __MINGW32__/__MINGW64__
+ symbols to simplify building with Microsoft Visual C++, since the
+ former are defined in both compiler configurations.
+ _________________________________________________________________
+
+Features of ncurses
+
+ The ncurses package is fully upward-compatible with SVr4 (System V
+ Release 4) curses:
+ * All of the SVr4 calls have been implemented (and are documented).
+ * ncurses supports all of the for SVr4 curses features including
+ keyboard mapping, color, forms-drawing with ACS characters, and
+ automatic recognition of keypad and function keys.
+ * ncurses provides these SVr4 add-on libraries (not part of X/Open
+ Curses):
+ + the panels library, supporting a stack of windows with
+ backing store.
+ + the menus library, supporting a uniform but flexible
+ interface for menu programming.
+ + the form library, supporting data collection through
+ on-screen forms.
+ * ncurses's terminal database is fully compatible with that used by
+ SVr4 curses.
+ + ncurses supports user-defined capabilities which it can see,
+ but which are hidden from SVr4 curses applications using the
+ same terminal database.
+ + It can be optionally configured to match the format used in
+ related systems such as AIX and Tru64.
+ + Alternatively, ncurses can be configured to use hashed
+ databases rather than the directory of files used by SVr4
+ curses.
+ * The ncurses utilities have options to allow you to filter terminfo
+ entries for use with less capable curses/terminfo versions such as
+ the HP/UX and AIX ports.