- 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 5.6; very few applications will require recompilation,
- depending on the platform. These are the highlights from the
- change-log since ncurses 5.6 release.
-
- Interface changes:
- * generate linkable stubs for some macros:
- getattrs
-
- New features and improvements:
- * library
- + new flavor of the ncurses library provides rudimentary
- support for POSIX threads. Several functions are reentrant,
- but most require either a window-level or screen-level mutex.
- (This is API-compatible, but not ABI-compatible with the
- normal library).
- + add NCURSES_OPAQUE symbol to curses.h, will use to make
- structs opaque in selected configurations.
- + add NCURSES_EXT_FUNCS and NCURSES_EXT_COLORS symbols to
- curses.h to make it simpler to tell if the extended functions
- and/or colors are declared.
- + add wresize() to C++ binding
- + eliminate fixed-buffer vsprintf() calls in C++ binding.
- + add several functions to C++ binding which wrap C functions
- that pass a WINDOW* parameter.
- + adapt mouse-handling code from menu library in form-library
- + improve tracing for form library, showing created forms,
- fields, etc.
- + make $NCURSES_NO_PADDING feature work for termcap interface .
- + add check to trace-file open, if the given name is a
- directory, add ".log" to the name and try again.
- + several new manpages: curs_legacy.3x, curs_memleaks.3x,
- curs_opaque.3x and curs_threads.3x
- * programs:
- + modified three test-programs to demonstrate the threading
- support in this version: ditto, rain, worm.
- + several new test-programs: demo_panels, dots_mvcur,
- inch_wide, inchs, key_name, key_names, savescreen,
- savescreen.sh test_arrays, test_get_wstr, test_getstr,
- test_instr, test_inwstr and test_opaque.
- + add adacurses-config to the Ada95 install.
- + modify tic -f option to format spaces as \s to prevent them
- from being lost when that is read back in unformatted
- strings.
- + The tack program is now distributed separately from ncurses.
- * terminal database
- + added entries:
- o Eterm-256color, Eterm-88color and rxvt-88color
- o aterm
- o konsole-256color
- o mrxvt
- o screen.mlterm
- o screen.rxvt
- o teraterm4.59 is now the primary primary teraterm entry,
- renamed original to teraterm2.3
- o 9term terminal
- o Newbury Data entries
- + updated/improved entries:
- o gnome to version 2.22.3
- o h19, z100
- o konsole to version 1.6.6
- o mlterm, mlterm+pcfkeys
- o xterm, and building-blocks for function-keys to [3]xterm
- patch #230.
-
- Major bug fixes:
- * add logic to tic for cancelling strings in user-defined
- capabilities (this is needed for current konsole terminfo entry).
- * modify mk-1st.awk so the generated makefile rules for linking or
- installing shared libraries do not first remove the library, in
- case it is in use, e.g., libncurses.so by /bin/sh.
- * correct check for notimeout() in wgetch().
- * fix a sign-extension bug in infocmp's repair_acsc() function.
- * change winnstr() to stop at the end of the line.
- * make Ada95 demo_panels() example work.
- * fix for adding a non-spacing character at the beginning of a line.
- * fill in extended-color pair to make colors work for
- wide-characters using extended-colors.
- * improve refresh of window on top of multi-column characters,
- taking into account split characters on left/right window
- boundaries.
- * modify win_wchnstr() to ensure that only a base cell is returned
- for each multi-column character.
- * improve waddch() and winsch() handling of EILSEQ from mbrtowc() by
- using unctrl() to display illegal bytes rather than trying to
- append further bytes to make up a valid sequence.
- * restore curs_set() state after endwin()/refresh()
- * modify keyname() to use "^X" form only if meta() has been called,
- or if keyname() is called without initializing curses, e.g., via
- initscr() or newterm().
- * modify unctrl() to check codes in 128-255 range versus isprint().
- If they are not printable, and locale was set, use a "M-" or "~"
- sequence.
- * improve resizeterm() by moving ripped-off lines, and repainting
- the soft-keys.
- * modify form library to accept control characters such as newline
- in set_field_buffer(), which is compatible with Solaris.
- * use NCURSES_MOUSE_MASK() in definition of BUTTON_RELEASE(), etc.,
- to make those work properly with the --enable-ext-mouse
- configuration
- * correct some functions in Ada95 binding which were using return
- value from C where none was returned.
- * reviewed/fixed issues reported by Coverity and Klocwork tools.
-
- Portability:
- * configure script:
- + new options:
-
- --disable-big-strings
- control whether static string tables are generated
- as single large strings (to improve startup
- performance), or as array of individual strings.
-
- --disable-relink
- control whether shared libraries are relinked
- (during install) when rpath is enabled.
-
- --disable-tic-depends
- make explicit whether tic library depends on
- ncurses/ncursesw library.
-
- --enable-mixed-case
- override the configure script's check if the
- filesystem supports mixed-case filenames. This
- allows one to control how the terminal database
- maps to the filesystem. For filesystems that do not
- support mixed-case, the library uses generate
- 2-character (hexadecimal) codes for the lower-level
- of the filesystem terminfo database
-
- --enable-reentrant
- builds a different flavor of the ncurses library
- (ncursest) which improves reentrant use of the
- library by reducing global and static variables
- (see the "--with-pthread" option for the threaded
- support).
-
- --enable-weak-symbols
- use weak-symbols for linking to the POSIX thread
- library, and use the same soname for the ncurses
- shared library as the normal library (caveat: the
- ABI is for the threaded library, which makes global
- data accessed via functions).
-
- --with-pthread
- build with the POSIX thread library (tested with
- AIX, Linux, FreeBSD, OpenBSD, HPUX, IRIX64,
- Solaris, Tru64).
-
- --with-ticlib
- build/install the tic-support functions in a
- separate library
-
- + improved options:
-
- --enable-ext-colors
- requires the wide-character configuration.
-
- --with-chtype
- ignore option value "unsigned" is always added to
- the type in curses.h; do the same for
- --with-mmask-t.
-
- --with-dmalloc
- build-fix for redefinition of strndup.
-
- --with-hashed-db
- accepts a parameter which is the install-prefix of
- a given Berkeley Database.
-
- --with-hashed-db
- the $LIBS environment variable overrides the search
- for the db library.
-
- --without-hashed-db
- assumed when "--disable-database" is used.
-
- * other configure/build issues:
- + build-fixes for LynxOS
- + modify shared-library rules to allow FreeBSD 3.x to use
- rpath.
- + build-fix for FreeBSD "contemporary" TTY interface.
- + build-fixes for AIX with libtool.
- + build-fixes for Darwin and libtool.
- + modify BeOS-specific ifdef's to build on Haiku.
- + corrected gcc options for building shared libraries on
- Solaris and IRIX64.
- + change shared-library configuration for OpenBSD, make rpath
- work.
- + build-fixes for using libutf8, e.g., on OpenBSD 3.7
- + add "-e" option in ncurses/Makefile.in when generating
- source-files to force earlier exit if the build environment
- fails unexpectedly.
- + add support for shared libraries for QNX.
- + change delimiter in MKlib_gen.sh from '%' to '@', to avoid
- substitution by IBM xlc to '#' as part of its extensions to
- digraphs.
- * library:
- + rewrite wrapper for wcrtomb(), making it work on Solaris.
- This is used in the form library to determine the length of
- the buffer needed by field_buffer.
- + add/use configure script macro CF_SIG_ATOMIC_T, use the
- corresponding type for data manipulated by signal handlers.
- + set locale in misc/ncurses-config.in since it uses a range
- + disable GPM mouse support when $TERM does not happen to
- contain "linux", since Gpm_Open() no longer limits its
- assertion to terminals that it might handle, e.g., within
- "screen" in xterm.
- + reset mouse file-descriptor when unloading GPM library.
- * test programs:
- + update test programs to build/work with various UNIX curses
- for comparisons.
-
- 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.