lib/libcurses/base/lib_set_term.c

root/lib/libcurses/base/lib_set_term.c
/* $OpenBSD: lib_set_term.c,v 1.15 2023/10/17 09:52:09 nicm Exp $ */

/****************************************************************************
 * Copyright 2018-2021,2022 Thomas E. Dickey                                *
 * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
 *                                                                          *
 * Permission is hereby granted, free of charge, to any person obtaining a  *
 * copy of this software and associated documentation files (the            *
 * "Software"), to deal in the Software without restriction, including      *
 * without limitation the rights to use, copy, modify, merge, publish,      *
 * distribute, distribute with modifications, sublicense, and/or sell       *
 * copies of the Software, and to permit persons to whom the Software is    *
 * furnished to do so, subject to the following conditions:                 *
 *                                                                          *
 * The above copyright notice and this permission notice shall be included  *
 * in all copies or substantial portions of the Software.                   *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
 *                                                                          *
 * Except as contained in this notice, the name(s) of the above copyright   *
 * holders shall not be used in advertising or otherwise to promote the     *
 * sale, use or other dealings in this Software without prior written       *
 * authorization.                                                           *
 ****************************************************************************/

/****************************************************************************
 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
 *     and: Thomas E. Dickey                        1996-on                 *
 *     and: Juergen Pfeifer                         2009                    *
 ****************************************************************************/

/*
**      lib_set_term.c
**
**      The routine set_term().
**
*/

#define NEW_PAIR_INTERNAL 1

#include <curses.priv.h>
#include <tic.h>
#include <new_pair.h>

#if USE_GPM_SUPPORT
#ifdef HAVE_LIBDL
/* use dynamic loader to avoid linkage dependency */
#include <dlfcn.h>
#endif
#endif

#undef CUR
#define CUR SP_TERMTYPE

MODULE_ID("$Id: lib_set_term.c,v 1.15 2023/10/17 09:52:09 nicm Exp $")

#ifdef USE_TERM_DRIVER
#define MaxColors      InfoOf(sp).maxcolors
#define NumLabels      InfoOf(sp).numlabels
#else
#define MaxColors      max_colors
#define NumLabels      num_labels
#endif

NCURSES_EXPORT(SCREEN *)
set_term(SCREEN *screenp)
{
    SCREEN *oldSP;
    SCREEN *newSP;

    T((T_CALLED("set_term(%p)"), (void *) screenp));

    _nc_lock_global(curses);

    oldSP = CURRENT_SCREEN;
    _nc_set_screen(screenp);
    newSP = screenp;

    if (newSP != 0) {
        TINFO_SET_CURTERM(newSP, newSP->_term);
#if !USE_REENTRANT
        curscr = CurScreen(newSP);
        newscr = NewScreen(newSP);
        stdscr = StdScreen(newSP);
        COLORS = newSP->_color_count;
        COLOR_PAIRS = newSP->_pair_count;
#endif
    } else {
        TINFO_SET_CURTERM(oldSP, 0);
#if !USE_REENTRANT
        curscr = 0;
        newscr = 0;
        stdscr = 0;
        COLORS = 0;
        COLOR_PAIRS = 0;
#endif
    }

    _nc_unlock_global(curses);

    T((T_RETURN("%p"), (void *) oldSP));
    return (oldSP);
}

static void
_nc_free_keytry(TRIES * kt)
{
    if (kt != 0) {
        _nc_free_keytry(kt->child);
        _nc_free_keytry(kt->sibling);
        free(kt);
    }
}

static bool
delink_screen(SCREEN *sp)
{
    SCREEN *last = 0;
    SCREEN *temp;
    bool result = FALSE;

    for (each_screen(temp)) {
        if (temp == sp) {
            if (last)
                last->_next_screen = sp->_next_screen;
            else
                _nc_screen_chain = sp->_next_screen;
            result = TRUE;
            break;
        }
        last = temp;
    }
    return result;
}

/*
 * Free the storage associated with the given SCREEN sp.
 */
NCURSES_EXPORT(void)
delscreen(SCREEN *sp)
{

    T((T_CALLED("delscreen(%p)"), (void *) sp));

    _nc_lock_global(curses);
    if (delink_screen(sp)) {
        WINDOWLIST *wl;
        bool is_current = (sp == CURRENT_SCREEN);

#ifdef USE_SP_RIPOFF
        if (safe_ripoff_sp && safe_ripoff_sp != safe_ripoff_stack) {
            ripoff_t *rop;
            for (rop = safe_ripoff_stack;
                 rop != safe_ripoff_sp && (rop - safe_ripoff_stack) < N_RIPS;
                 rop++) {
                if (rop->win) {
                    (void) delwin(rop->win);
                    rop->win = 0;
                }
            }
        }
#endif

        /* delete all of the windows in this screen */
      rescan:
        for (each_window(sp, wl)) {
            if (_nc_freewin(&(wl->win)) == OK) {
                goto rescan;
            }
        }

        if (sp->_slk != 0) {

            if (sp->_slk->ent != 0) {
                int i;

                for (i = 0; i < sp->_slk->labcnt; ++i) {
                    FreeIfNeeded(sp->_slk->ent[i].ent_text);
                    FreeIfNeeded(sp->_slk->ent[i].form_text);
                }
                free(sp->_slk->ent);
            }
            free(sp->_slk);
            sp->_slk = 0;
        }

        _nc_free_keytry(sp->_keytry);
        sp->_keytry = 0;

        _nc_free_keytry(sp->_key_ok);
        sp->_key_ok = 0;

        FreeIfNeeded(sp->_current_attr);

        _nc_free_ordered_pairs(sp);
        FreeIfNeeded(sp->_color_table);
        FreeIfNeeded(sp->_color_pairs);

        FreeIfNeeded(sp->_oldnum_list);
        FreeIfNeeded(sp->oldhash);
        FreeIfNeeded(sp->newhash);
        FreeIfNeeded(sp->hashtab);

        FreeIfNeeded(sp->_acs_map);
        FreeIfNeeded(sp->_screen_acs_map);

        NCURSES_SP_NAME(_nc_flush) (NCURSES_SP_ARG);
        NCURSES_SP_NAME(del_curterm) (NCURSES_SP_ARGx sp->_term);
        FreeIfNeeded(sp->out_buffer);
        if (_nc_find_prescr() == sp) {
            _nc_forget_prescr();
        }
#if USE_GPM_SUPPORT
#ifdef HAVE_LIBDL
        if (sp->_dlopen_gpm != 0) {
            dlclose(sp->_dlopen_gpm);
            sp->_dlopen_gpm = 0;
        }
#endif
#endif /* USE_GPM_SUPPORT */
        free(sp);

        /*
         * If this was the current screen, reset everything that the
         * application might try to use (except cur_term, which may have
         * multiple references in different screens).
         */
        if (is_current) {
#if !USE_REENTRANT
            curscr = 0;
            newscr = 0;
            stdscr = 0;
            COLORS = 0;
            COLOR_PAIRS = 0;
#endif
            _nc_set_screen(0);
#if USE_WIDEC_SUPPORT
            if (SP == 0) {
                FreeIfNeeded(_nc_wacs);
                _nc_wacs = 0;
            }
#endif
        } else {
            set_term(CURRENT_SCREEN);
        }
    }
    _nc_unlock_global(curses);

    returnVoid;
}

static bool
no_mouse_event(SCREEN *sp GCC_UNUSED)
{
    return FALSE;
}

static bool
no_mouse_inline(SCREEN *sp GCC_UNUSED)
{
    return FALSE;
}

static bool
no_mouse_parse(SCREEN *sp GCC_UNUSED, int code GCC_UNUSED)
{
    return TRUE;
}

static void
no_mouse_resume(SCREEN *sp GCC_UNUSED)
{
}

static void
no_mouse_wrap(SCREEN *sp GCC_UNUSED)
{
}

#if NCURSES_EXT_FUNCS && USE_COLORFGBG
static const char *
extract_fgbg(const char *src, int *result)
{
    const char *dst = 0;
    char *tmp = 0;
    long value = strtol(src, &tmp, 0);

    if ((dst = tmp) == 0) {
        dst = src;
    } else if (value >= 0) {
        *result = (int) value;
    }
    while (*dst != 0 && *dst != ';')
        dst++;
    if (*dst == ';')
        dst++;
    return dst;
}
#endif

#define ReturnScreenError() do { _nc_set_screen(0); \
                            returnCode(ERR); } while (0)

/* OS-independent screen initializations */
NCURSES_EXPORT(int)
NCURSES_SP_NAME(_nc_setupscreen) (
#if NCURSES_SP_FUNCS
                                     SCREEN **spp,
#endif
                                     int slines,
                                     int scolumns,
                                     FILE *output,
                                     int filtered,
                                     int slk_format)
{
#ifndef USE_TERM_DRIVER
    static const TTY null_TTY;  /* all zeros iff uninitialized */
#endif
    char *env;
    int bottom_stolen = 0;
    SCREEN *sp;
#ifndef USE_TERM_DRIVER
    bool support_cookies = USE_XMC_SUPPORT;
#endif

    T((T_CALLED("_nc_setupscreen(%d, %d, %p, %d, %d)"),
       slines, scolumns, (void *) output, filtered, slk_format));

    assert(CURRENT_SCREEN == 0);        /* has been reset in newterm() ! */

#if NCURSES_SP_FUNCS
    assert(spp != 0);
    sp = *spp;

    if (!sp) {
        sp = _nc_alloc_screen_sp();
        T(("_nc_alloc_screen_sp %p", (void *) sp));
        *spp = sp;
    }
    if (sp == NULL) {
        ReturnScreenError();
    }
    if ((sp->_acs_map = typeCalloc(chtype, ACS_LEN)) == NULL) {
        ReturnScreenError();
    }
    if ((sp->_screen_acs_map = typeCalloc(bool, ACS_LEN)) == NULL) {
        free(sp->_acs_map);
        ReturnScreenError();
    }

    T(("created SP %p", (void *) sp));
    sp->_next_screen = _nc_screen_chain;
    _nc_screen_chain = sp;

    if ((sp->_current_attr = typeCalloc(NCURSES_CH_T, 1)) == 0) {
        ReturnScreenError();
    }
#else
    if (!_nc_alloc_screen()
        || ((SP->_acs_map = typeCalloc(chtype, ACS_LEN)) == 0)
        || ((SP->_screen_acs_map = typeCalloc(bool, ACS_LEN)) == 0)) {
        returnCode(ERR);
    }

    T(("created SP %p", (void *) SP));

    sp = SP;                    /* fixup so SET_LINES and SET_COLS works */
    sp->_next_screen = _nc_screen_chain;
    _nc_screen_chain = sp;

    if ((sp->_current_attr = typeCalloc(NCURSES_CH_T, 1)) == 0) {
        returnCode(ERR);
    }
#endif

    /*
     * We should always check the screensize, just in case.
     */
    _nc_set_screen(sp);
    sp->_term = cur_term;
#ifdef USE_TERM_DRIVER
    TCBOf(sp)->csp = sp;
    _nc_get_screensize(sp, sp->_term, &slines, &scolumns);
#else
    _nc_get_screensize(sp, &slines, &scolumns);
#endif
    SET_LINES(slines);
    SET_COLS(scolumns);

    T((T_CREATE("screen %s %dx%d"),
       NCURSES_SP_NAME(termname) (NCURSES_SP_ARG), slines, scolumns));

    sp->_filtered = filtered;

    /* implement filter mode */
    if (filtered) {
        slines = 1;
        SET_LINES(slines);
#ifdef USE_TERM_DRIVER
        CallDriver(sp, td_setfilter);
#else
        /* *INDENT-EQLS* */
        clear_screen     = ABSENT_STRING;
        cursor_address   = ABSENT_STRING;
        cursor_down      = ABSENT_STRING;
        cursor_up        = ABSENT_STRING;
        parm_down_cursor = ABSENT_STRING;
        parm_up_cursor   = ABSENT_STRING;
        row_address      = ABSENT_STRING;
        cursor_home      = carriage_return;

        if (back_color_erase)
            clr_eos = ABSENT_STRING;

#endif
        T(("filter screensize %dx%d", slines, scolumns));
    }
#ifdef __DJGPP__
    T(("setting output mode to binary"));
    fflush(output);
    setmode(output, O_BINARY);
#endif
#if defined(EXP_WIN32_DRIVER)
    T(("setting output mode to binary"));
    fflush(output);
    _setmode(fileno(output), _O_BINARY);
#endif
    sp->_lines = (NCURSES_SIZE_T) slines;
    sp->_lines_avail = (NCURSES_SIZE_T) slines;
    sp->_columns = (NCURSES_SIZE_T) scolumns;

    fflush(output);
    sp->_ofd = output ? fileno(output) : -1;
    sp->_ofp = output;
#if defined(EXP_WIN32_DRIVER)
    if (output)
        _setmode(fileno(output), _O_BINARY);
#endif
    sp->out_limit = (size_t) ((2 + slines) * (6 + scolumns));
    if ((sp->out_buffer = malloc(sp->out_limit)) == 0)
        sp->out_limit = 0;
    sp->out_inuse = 0;

    SP_PRE_INIT(sp);
    SetNoPadding(sp);

#if NCURSES_EXT_FUNCS
    sp->_default_color = FALSE;
    sp->_has_sgr_39_49 = FALSE;

    /*
     * Set our assumption of the terminal's default foreground and background
     * colors.  The curs_color man-page states that we can assume that the
     * background is black.  The origin of this assumption appears to be
     * terminals that displayed colored text, but no colored backgrounds, e.g.,
     * the first colored terminals around 1980.  More recent ones with better
     * technology can display not only colored backgrounds, but all
     * combinations.  So a terminal might be something other than "white" on
     * black (green/black looks monochrome too), but black on white or even
     * on ivory.
     *
     * White-on-black is the simplest thing to use for monochrome.  Almost
     * all applications that use color paint both text and background, so
     * the distinction is moot.  But a few do not - which is why we leave this
     * configurable (a better solution is to use assume_default_colors() for
     * the rare applications that do require that sort of appearance, since
     * is appears that more users expect to be able to make a white-on-black
     * or black-on-white display under control of the application than not).
     */
#ifdef USE_ASSUMED_COLOR
    sp->_default_fg = COLOR_WHITE;
    sp->_default_bg = COLOR_BLACK;
#else
    sp->_default_fg = COLOR_DEFAULT;
    sp->_default_bg = COLOR_DEFAULT;
#endif

    /*
     * Allow those assumed/default color assumptions to be overridden at
     * runtime:
     */
    if ((env = getenv("NCURSES_ASSUMED_COLORS")) != 0) {
        int fg, bg;
        char sep1, sep2;
        int count = sscanf(env, "%d%c%d%c", &fg, &sep1, &bg, &sep2);
        if (count >= 1) {
            sp->_default_fg = ((fg >= 0 && fg < MaxColors) ? fg : COLOR_DEFAULT);
            if (count >= 3) {
                sp->_default_bg = ((bg >= 0 && bg < MaxColors) ? bg : COLOR_DEFAULT);
            }
            TR(TRACE_CHARPUT | TRACE_MOVE,
               ("from environment assumed fg=%d, bg=%d",
                sp->_default_fg,
                sp->_default_bg));
        }
    }
#if USE_COLORFGBG
    /*
     * If rxvt's $COLORFGBG variable is set, use it to specify the assumed
     * default colors.  Note that rxvt (mis)uses bold colors, equating a bold
     * color to that value plus 8.  We'll only use the non-bold color for now -
     * decide later if it is worth having default attributes as well.
     */
    if (getenv("COLORFGBG") != 0) {
        const char *p = getenv("COLORFGBG");
        TR(TRACE_CHARPUT | TRACE_MOVE, ("decoding COLORFGBG %s", p));
        p = extract_fgbg(p, &(sp->_default_fg));
        p = extract_fgbg(p, &(sp->_default_bg));
        if (*p)                 /* assume rxvt was compiled with xpm support */
            extract_fgbg(p, &(sp->_default_bg));
        TR(TRACE_CHARPUT | TRACE_MOVE, ("decoded fg=%d, bg=%d",
                                        sp->_default_fg, sp->_default_bg));
        if (sp->_default_fg >= MaxColors) {
            if (set_a_foreground != ABSENT_STRING
                && !strcmp(set_a_foreground, "\033[3%p1%dm")) {
                set_a_foreground = strdup("\033[3%?%p1%{8}%>%t9%e%p1%d%;m");
            } else {
                sp->_default_fg %= MaxColors;
            }
        }
        if (sp->_default_bg >= MaxColors) {
            if (set_a_background != ABSENT_STRING
                && !strcmp(set_a_background, "\033[4%p1%dm")) {
                set_a_background = strdup("\033[4%?%p1%{8}%>%t9%e%p1%d%;m");
            } else {
                sp->_default_bg %= MaxColors;
            }
        }
    }
#endif
#endif /* NCURSES_EXT_FUNCS */

    sp->_maxclick = DEFAULT_MAXCLICK;
    sp->_mouse_event = no_mouse_event;
    sp->_mouse_inline = no_mouse_inline;
    sp->_mouse_parse = no_mouse_parse;
    sp->_mouse_resume = no_mouse_resume;
    sp->_mouse_wrap = no_mouse_wrap;
    sp->_mouse_fd = -1;

    /*
     * If we've no magic cookie support, we suppress attributes that xmc would
     * affect, i.e., the attributes that affect the rendition of a space.
     */
    sp->_ok_attributes = NCURSES_SP_NAME(termattrs) (NCURSES_SP_ARG);
    if (NCURSES_SP_NAME(has_colors) (NCURSES_SP_ARG)) {
        sp->_ok_attributes |= A_COLOR;
    }
#ifdef USE_TERM_DRIVER
    _nc_cookie_init(sp);
#else
#if USE_XMC_SUPPORT
    /*
     * If we have no magic-cookie support compiled-in, or if it is suppressed
     * in the environment, reset the support-flag.
     */
    if (magic_cookie_glitch >= 0) {
        if (getenv("NCURSES_NO_MAGIC_COOKIE") != 0) {
            support_cookies = FALSE;
        }
    }
#endif

    if (!support_cookies && magic_cookie_glitch >= 0) {
        T(("will disable attributes to work w/o magic cookies"));
    }

    if (magic_cookie_glitch > 0) {      /* tvi, wyse */

        sp->_xmc_triggers = sp->_ok_attributes & XMC_CONFLICT;
#if 0
        /*
         * We "should" treat colors as an attribute.  The wyse350 (and its
         * clones) appear to be the only ones that have both colors and magic
         * cookies.
         */
        if (has_colors()) {
            sp->_xmc_triggers |= A_COLOR;
        }
#endif
        sp->_xmc_suppress = sp->_xmc_triggers & (chtype) ~(A_BOLD);

        T(("magic cookie attributes %s", _traceattr(sp->_xmc_suppress)));
        /*
         * Supporting line-drawing may be possible.  But make the regular
         * video attributes work first.
         */
        acs_chars = ABSENT_STRING;
        ena_acs = ABSENT_STRING;
        enter_alt_charset_mode = ABSENT_STRING;
        exit_alt_charset_mode = ABSENT_STRING;
#if USE_XMC_SUPPORT
        /*
         * To keep the cookie support simple, suppress all of the optimization
         * hooks except for clear_screen and the cursor addressing.
         */
        if (support_cookies) {
            clr_eol = ABSENT_STRING;
            clr_eos = ABSENT_STRING;
            set_attributes = ABSENT_STRING;
        }
#endif
    } else if (magic_cookie_glitch == 0) {      /* hpterm */
    }

    /*
     * If magic cookies are not supported, cancel the strings that set
     * video attributes.
     */
    if (!support_cookies && magic_cookie_glitch >= 0) {
        magic_cookie_glitch = ABSENT_NUMERIC;
        set_attributes = ABSENT_STRING;
        enter_blink_mode = ABSENT_STRING;
        enter_bold_mode = ABSENT_STRING;
        enter_dim_mode = ABSENT_STRING;
        enter_reverse_mode = ABSENT_STRING;
        enter_standout_mode = ABSENT_STRING;
        enter_underline_mode = ABSENT_STRING;
    }

    /* initialize normal acs before wide, since we use mapping in the latter */
#if !USE_WIDEC_SUPPORT
    if (_nc_unicode_locale() && _nc_locale_breaks_acs(sp->_term)) {
        acs_chars = NULL;
        ena_acs = NULL;
        enter_alt_charset_mode = NULL;
        exit_alt_charset_mode = NULL;
        set_attributes = NULL;
    }
#endif
#endif

    NCURSES_SP_NAME(_nc_init_acs) (NCURSES_SP_ARG);
#if USE_WIDEC_SUPPORT
    sp->_screen_unicode = _nc_unicode_locale();
    if (_nc_wacs == 0) {
        _nc_init_wacs();
    }
    if (_nc_wacs == 0) {
        ReturnScreenError();
    }

    sp->_screen_acs_fix = (sp->_screen_unicode
                           && _nc_locale_breaks_acs(sp->_term));
#endif
    env = _nc_get_locale();
    sp->_legacy_coding = ((env == 0)
                          || !strcmp(env, "C")
                          || !strcmp(env, "POSIX"));
    T(("legacy-coding %d", sp->_legacy_coding));

    sp->_nc_sp_idcok = TRUE;
    sp->_nc_sp_idlok = FALSE;

    sp->oldhash = 0;
    sp->newhash = 0;

    T(("creating newscr"));
    NewScreen(sp) = NCURSES_SP_NAME(newwin) (NCURSES_SP_ARGx slines, scolumns,
                                             0, 0);
    if (NewScreen(sp) == 0) {
        ReturnScreenError();
    }
    T(("creating curscr"));
    CurScreen(sp) = NCURSES_SP_NAME(newwin) (NCURSES_SP_ARGx slines, scolumns,
                                             0, 0);
    if (CurScreen(sp) == 0) {
        ReturnScreenError();
    }
#if !USE_REENTRANT
    newscr = NewScreen(sp);
    curscr = CurScreen(sp);
#endif
#if USE_SIZECHANGE
    sp->_resize = NCURSES_SP_NAME(resizeterm);
    sp->_ungetch = safe_ungetch;
#endif

    NewScreen(sp)->_clear = TRUE;
    CurScreen(sp)->_clear = FALSE;

    /*
     * Get the current tty-modes. setupterm() may already have done this,
     * unless we use the term-driver.
     */
#ifndef USE_TERM_DRIVER
    if (cur_term != 0 &&
        !memcmp(&cur_term->Ottyb, &null_TTY, sizeof(TTY)))
#endif
    {
        NCURSES_SP_NAME(def_shell_mode) (NCURSES_SP_ARG);
        NCURSES_SP_NAME(def_prog_mode) (NCURSES_SP_ARG);
    }

    if (safe_ripoff_sp && safe_ripoff_sp != safe_ripoff_stack) {
        ripoff_t *rop;

        for (rop = safe_ripoff_stack;
             rop != safe_ripoff_sp && (rop - safe_ripoff_stack) < N_RIPS;
             rop++) {

            /* If we must simulate soft labels, grab off the line to be used.
               We assume that we must simulate, if it is none of the standard
               formats (4-4 or 3-2-3) for which there may be some hardware
               support. */
            if (rop->hook == _nc_slk_initialize) {
                if (!TerminalOf(sp)) {
                    continue;
                }
                if (!(NumLabels <= 0 || !SLK_STDFMT(slk_format))) {
                    continue;
                }
            }
            if (rop->hook) {
                int count;
                WINDOW *w;

                count = (rop->line < 0) ? -rop->line : rop->line;
                T(("ripping off %i lines at %s", count,
                   ((rop->line < 0)
                    ? "bottom"
                    : "top")));

                w = NCURSES_SP_NAME(newwin) (NCURSES_SP_ARGx
                                             count, scolumns,
                                             ((rop->line < 0)
                                              ? sp->_lines_avail - count
                                              : 0),
                                             0);
                if (w) {
                    rop->win = w;
                    rop->hook(w, scolumns);
                } else {
                    ReturnScreenError();
                }
                if (rop->line < 0) {
                    bottom_stolen += count;
                } else {
                    sp->_topstolen = (NCURSES_SIZE_T) (sp->_topstolen + count);
                }
                sp->_lines_avail = (NCURSES_SIZE_T) (sp->_lines_avail - count);
            }
        }
        /* reset the stack */
        safe_ripoff_sp = safe_ripoff_stack;
    }

    T(("creating stdscr"));
    (void) bottom_stolen;
    assert((sp->_lines_avail + sp->_topstolen + bottom_stolen) == slines);
    if ((StdScreen(sp) = NCURSES_SP_NAME(newwin) (NCURSES_SP_ARGx
                                                  sp->_lines_avail,
                                                  scolumns, 0, 0)) == 0) {
        ReturnScreenError();
    }
    SET_LINES(sp->_lines_avail);
#if !USE_REENTRANT
    stdscr = StdScreen(sp);
#endif
    sp->_prescreen = FALSE;
    returnCode(OK);
}

#if NCURSES_SP_FUNCS
NCURSES_EXPORT(int)
_nc_setupscreen(int slines GCC_UNUSED,
                int scolumns GCC_UNUSED,
                FILE *output,
                int filtered,
                int slk_format)
{
    SCREEN *sp = 0;
    int rc = NCURSES_SP_NAME(_nc_setupscreen) (&sp,
                                               slines,
                                               scolumns,
                                               output,
                                               filtered,
                                               slk_format);
    if (rc != OK)
        _nc_set_screen(0);
    return rc;
}
#endif

/*
 * The internal implementation interprets line as the number of lines to rip
 * off from the top or bottom.
 */
NCURSES_EXPORT(int)
NCURSES_SP_NAME(_nc_ripoffline) (NCURSES_SP_DCLx
                                 int line,
                                 int (*init) (WINDOW *, int))
{
    int code = ERR;
    TR_FUNC_BFR(1);

    START_TRACE();
    T((T_CALLED("ripoffline(%p,%d,%s)"),
       (void *) SP_PARM, line,
       TR_FUNC_ARG(0, init)));

#if NCURSES_SP_FUNCS
    if (SP_PARM != 0 && SP_PARM->_prescreen)
#endif
    {
        if (line == 0) {
            code = OK;
        } else {
            if (safe_ripoff_sp == 0) {
                safe_ripoff_sp = safe_ripoff_stack;
            }
            if (safe_ripoff_sp < safe_ripoff_stack + N_RIPS) {
                safe_ripoff_sp->line = line;
                safe_ripoff_sp->hook = init;
                (safe_ripoff_sp)++;
                T(("ripped-off %d:%d chunks",
                   (int) (safe_ripoff_sp - safe_ripoff_stack), N_RIPS));
                code = OK;
            }
        }
    }

    returnCode(code);
}

#if NCURSES_SP_FUNCS
NCURSES_EXPORT(int)
_nc_ripoffline(int line, int (*init) (WINDOW *, int))
{
    int rc;

    _nc_init_pthreads();
    _nc_lock_global(prescreen);
    START_TRACE();
    rc = NCURSES_SP_NAME(_nc_ripoffline) (CURRENT_SCREEN_PRE, line, init);
    _nc_unlock_global(prescreen);

    return rc;
}
#endif

NCURSES_EXPORT(int)
NCURSES_SP_NAME(ripoffline) (NCURSES_SP_DCLx
                             int line,
                             int (*init) (WINDOW *, int))
{
    START_TRACE();
    return NCURSES_SP_NAME(_nc_ripoffline) (NCURSES_SP_ARGx
                                            (line < 0) ? -1 : 1,
                                            init);
}

#if NCURSES_SP_FUNCS
NCURSES_EXPORT(int)
ripoffline(int line, int (*init) (WINDOW *, int))
{
    int rc;

    _nc_init_pthreads();
    _nc_lock_global(prescreen);
    START_TRACE();
    rc = NCURSES_SP_NAME(ripoffline) (CURRENT_SCREEN_PRE, line, init);
    _nc_unlock_global(prescreen);

    return rc;
}
#endif