ncurses/tinfo/alloc_entry.c - third_party/ncurses - Git at Google

 /****************************************************************************
  * Copyright 2018-2021,2022 Thomas E. Dickey                                *
  * Copyright 1998-2013,2017 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                 *
  ****************************************************************************/

 /*
  * alloc_entry.c -- allocation functions for terminfo entries
  *
  *	_nc_copy_entry()
  *	_nc_init_entry()
  *	_nc_merge_entry()
  *	_nc_save_str()
  *	_nc_wrap_entry()
  *
  */

 #include <curses.priv.h>

 #include <tic.h>

 MODULE_ID("$Id: alloc_entry.c,v 1.77 2022/10/15 19:37:33 tom Exp $")

 #define ABSENT_OFFSET    -1
 #define CANCELLED_OFFSET -2

 static char *stringbuf;		/* buffer for string capabilities */
 static size_t next_free;	/* next free character in stringbuf */

 NCURSES_EXPORT(void)
 _nc_init_entry(ENTRY * const tp)
 /* initialize a terminal type data block */
 {
     DEBUG(2, (T_CALLED("_nc_init_entry(tp=%p)"), (void *) tp));

     if (tp == NULL) {
 #if NO_LEAKS
 	if (stringbuf != NULL) {
 	    FreeAndNull(stringbuf);
 	}
 	return;
 #else
 	_nc_err_abort("_nc_init_entry called without initialization");
 #endif
     }

     if (stringbuf == NULL)
 	TYPE_CALLOC(char, (size_t) MAX_ENTRY_SIZE, stringbuf);

     next_free = 0;

     _nc_init_termtype(&(tp->tterm));

     DEBUG(2, (T_RETURN("")));
 }

 NCURSES_EXPORT(ENTRY *)
 _nc_copy_entry(ENTRY * oldp)
 {
     ENTRY *newp;

     DEBUG(2, (T_CALLED("_nc_copy_entry(oldp=%p)"), (void *) oldp));

     newp = typeCalloc(ENTRY, 1);
     if (newp != NULL) {
 	*newp = *oldp;
 	_nc_copy_termtype2(&(newp->tterm), &(oldp->tterm));
     }

     DEBUG(2, (T_RETURN("%p"), (void *) newp));
     return (newp);
 }

 /* save a copy of string in the string buffer */
 NCURSES_EXPORT(char *)
 _nc_save_str(const char *string)
 {
     char *result = 0;
     size_t old_next_free = next_free;

     if (stringbuf != NULL) {
 	size_t len;

 	if (!VALID_STRING(string))
 	    string = "";
 	len = strlen(string) + 1;

 	if (len == 1 && next_free != 0) {
 	    /*
 	     * Cheat a little by making an empty string point to the end of the
 	     * previous string.
 	     */
 	    if (next_free < MAX_ENTRY_SIZE) {
 		result = (stringbuf + next_free - 1);
 	    }
 	} else if (next_free + len < MAX_ENTRY_SIZE) {
 	    _nc_STRCPY(&stringbuf[next_free], string, MAX_ENTRY_SIZE);
 	    DEBUG(7, ("Saved string %s", _nc_visbuf(string)));
 	    DEBUG(7, ("at location %d", (int) next_free));
 	    next_free += len;
 	    result = (stringbuf + old_next_free);
 	} else {
 	    _nc_warning("Too much data, some is lost: %s", string);
 	}
     }
     return result;
 }

 NCURSES_EXPORT(void)
 _nc_wrap_entry(ENTRY * const ep, bool copy_strings)
 /* copy the string parts to allocated storage, preserving pointers to it */
 {
     int offsets[MAX_ENTRY_SIZE / sizeof(short)];
     int useoffsets[MAX_USES];
     unsigned i, n;
     unsigned nuses;
     TERMTYPE2 *tp;

     DEBUG(2, (T_CALLED("_nc_wrap_entry(ep=%p, copy_strings=%d)"), (void *)
 	      ep, copy_strings));
     if (ep == NULL || stringbuf == NULL)
 	_nc_err_abort("_nc_wrap_entry called without initialization");

     nuses = ep->nuses;
     tp = &(ep->tterm);
     if (copy_strings) {
 	next_free = 0;		/* clear static storage */

 	/* copy term_names, Strings, uses */
 	tp->term_names = _nc_save_str(tp->term_names);
 	for_each_string(i, tp) {
 	    if (tp->Strings[i] != ABSENT_STRING &&
 		tp->Strings[i] != CANCELLED_STRING) {
 		tp->Strings[i] = _nc_save_str(tp->Strings[i]);
 	    }
 	}

 	for (i = 0; i < nuses; i++) {
 	    if (ep->uses[i].name == 0) {
 		ep->uses[i].name = _nc_save_str(ep->uses[i].name);
 	    }
 	}

 	free(tp->str_table);
     }

     assert(tp->term_names >= stringbuf);
     n = (unsigned) (tp->term_names - stringbuf);
     for_each_string(i, &(ep->tterm)) {
 	if (i < SIZEOF(offsets)) {
 	    if (tp->Strings[i] == ABSENT_STRING) {
 		offsets[i] = ABSENT_OFFSET;
 	    } else if (tp->Strings[i] == CANCELLED_STRING) {
 		offsets[i] = CANCELLED_OFFSET;
 	    } else {
 		offsets[i] = (int) (tp->Strings[i] - stringbuf);
 	    }
 	}
     }

     for (i = 0; i < nuses; i++) {
 	if (ep->uses[i].name == 0)
 	    useoffsets[i] = ABSENT_OFFSET;
 	else
 	    useoffsets[i] = (int) (ep->uses[i].name - stringbuf);
     }

     TYPE_MALLOC(char, next_free, tp->str_table);
     (void) memcpy(tp->str_table, stringbuf, next_free);

     tp->term_names = tp->str_table + n;
     for_each_string(i, &(ep->tterm)) {
 	if (i < SIZEOF(offsets)) {
 	    if (offsets[i] == ABSENT_OFFSET) {
 		tp->Strings[i] = ABSENT_STRING;
 	    } else if (offsets[i] == CANCELLED_OFFSET) {
 		tp->Strings[i] = CANCELLED_STRING;
 	    } else {
 		tp->Strings[i] = tp->str_table + offsets[i];
 	    }
 	}
     }

 #if NCURSES_XNAMES
     if (!copy_strings) {
 	if ((n = (unsigned) NUM_EXT_NAMES(tp)) != 0) {
 	    if (n < SIZEOF(offsets)) {
 		size_t length = 0;
 		size_t offset;
 		for (i = 0; i < n; i++) {
 		    length += strlen(tp->ext_Names[i]) + 1;
 		    offsets[i] = (int) (tp->ext_Names[i] - stringbuf);
 		}
 		TYPE_MALLOC(char, length, tp->ext_str_table);
 		for (i = 0, offset = 0; i < n; i++) {
 		    tp->ext_Names[i] = tp->ext_str_table + offset;
 		    _nc_STRCPY(tp->ext_Names[i],
 			       stringbuf + offsets[i],
 			       length - offset);
 		    offset += strlen(tp->ext_Names[i]) + 1;
 		}
 	    }
 	}
     }
 #endif

     for (i = 0; i < nuses; i++) {
 	if (useoffsets[i] == ABSENT_OFFSET) {
 	    ep->uses[i].name = 0;
 	} else {
 	    ep->uses[i].name = strdup(tp->str_table + useoffsets[i]);
 	}
     }
     DEBUG(2, (T_RETURN("")));
 }

 NCURSES_EXPORT(void)
 _nc_merge_entry(ENTRY * const target, ENTRY * const source)
 /* merge capabilities from `from' entry into `to' entry */
 {
     TERMTYPE2 *to = &(target->tterm);
     TERMTYPE2 *from = &(source->tterm);
 #if NCURSES_XNAMES
     TERMTYPE2 copy;
     size_t str_size;
     char *str_table;
 #endif
     unsigned i;

     if (source == 0 || from == 0 || target == 0 || to == 0)
 	return;

 #if NCURSES_XNAMES
     _nc_copy_termtype2(&copy, from);
     from = &copy;
     _nc_align_termtype(to, from);
     /*
      * compute the maximum size of the string-table.
      */
     str_size = strlen(to->term_names) + 1;
     for_each_string(i, from) {
 	if (VALID_STRING(from->Strings[i]))
 	    str_size += strlen(from->Strings[i]) + 1;
     }
     for_each_string(i, to) {
 	if (VALID_STRING(to->Strings[i]))
 	    str_size += strlen(to->Strings[i]) + 1;
     }
     /* allocate a string-table large enough for both source/target, and
      * copy all of the strings into that table.  In the merge, we will
      * select from the original source/target lists to construct a new
      * target list.
      */
     if (str_size != 0) {
 	char *str_copied;
 	if ((str_table = malloc(str_size)) == NULL)
 	    _nc_err_abort(MSG_NO_MEMORY);
 	str_copied = str_table;
 	strcpy(str_copied, to->term_names);
 	to->term_names = str_copied;
 	str_copied += strlen(str_copied) + 1;
 	for_each_string(i, from) {
 	    if (VALID_STRING(from->Strings[i])) {
 		strcpy(str_copied, from->Strings[i]);
 		from->Strings[i] = str_copied;
 		str_copied += strlen(str_copied) + 1;
 	    }
 	}
 	for_each_string(i, to) {
 	    if (VALID_STRING(to->Strings[i])) {
 		strcpy(str_copied, to->Strings[i]);
 		to->Strings[i] = str_copied;
 		str_copied += strlen(str_copied) + 1;
 	    }
 	}
 	free(to->str_table);
 	to->str_table = str_table;
 	free(from->str_table);
     }
     /*
      * Do the same for the extended-strings (i.e., lists of capabilities).
      */
     str_size = 0;
     for (i = 0; i < NUM_EXT_NAMES(from); ++i) {
 	if (VALID_STRING(from->ext_Names[i]))
 	    str_size += strlen(from->ext_Names[i]) + 1;
     }
     for (i = 0; i < NUM_EXT_NAMES(to); ++i) {
 	if (VALID_STRING(to->ext_Names[i]))
 	    str_size += strlen(to->ext_Names[i]) + 1;
     }
     /* allocate a string-table large enough for both source/target, and
      * copy all of the strings into that table.  In the merge, we will
      * select from the original source/target lists to construct a new
      * target list.
      */
     if (str_size != 0) {
 	char *str_copied;
 	if ((str_table = malloc(str_size)) == NULL)
 	    _nc_err_abort(MSG_NO_MEMORY);
 	str_copied = str_table;
 	for (i = 0; i < NUM_EXT_NAMES(from); ++i) {
 	    if (VALID_STRING(from->ext_Names[i])) {
 		strcpy(str_copied, from->ext_Names[i]);
 		from->ext_Names[i] = str_copied;
 		str_copied += strlen(str_copied) + 1;
 	    }
 	}
 	for (i = 0; i < NUM_EXT_NAMES(to); ++i) {
 	    if (VALID_STRING(to->ext_Names[i])) {
 		strcpy(str_copied, to->ext_Names[i]);
 		to->ext_Names[i] = str_copied;
 		str_copied += strlen(str_copied) + 1;
 	    }
 	}
 	free(to->ext_str_table);
 	to->ext_str_table = str_table;
 	free(from->ext_str_table);
     }
 #endif
     for_each_boolean(i, from) {
 	if (to->Booleans[i] != (NCURSES_SBOOL) CANCELLED_BOOLEAN) {
 	    int mergebool = from->Booleans[i];

 	    if (mergebool == CANCELLED_BOOLEAN)
 		to->Booleans[i] = FALSE;
 	    else if (mergebool == TRUE)
 		to->Booleans[i] = (NCURSES_SBOOL) mergebool;
 	}
     }

     for_each_number(i, from) {
 	if (to->Numbers[i] != CANCELLED_NUMERIC) {
 	    int mergenum = from->Numbers[i];

 	    if (mergenum == CANCELLED_NUMERIC)
 		to->Numbers[i] = ABSENT_NUMERIC;
 	    else if (mergenum != ABSENT_NUMERIC)
 		to->Numbers[i] = (NCURSES_INT2) mergenum;
 	}
     }

     /*
      * Note: the copies of strings this makes don't have their own
      * storage.  This is OK right now, but will be a problem if we
      * we ever want to deallocate entries.
      */
     for_each_string(i, from) {
 	if (to->Strings[i] != CANCELLED_STRING) {
 	    char *mergestring = from->Strings[i];

 	    if (mergestring == CANCELLED_STRING)
 		to->Strings[i] = ABSENT_STRING;
 	    else if (mergestring != ABSENT_STRING)
 		to->Strings[i] = mergestring;
 	}
     }
 #if NCURSES_XNAMES
     /* cleanup */
     free(copy.Booleans);
     free(copy.Numbers);
     free(copy.Strings);
     free(copy.ext_Names);
 #endif
 }

 #if NO_LEAKS
 NCURSES_EXPORT(void)
 _nc_alloc_entry_leaks(void)
 {
     if (stringbuf != NULL) {
 	FreeAndNull(stringbuf);
     }
     next_free = 0;
 }
 #endif
	/****************************************************************************
	* Copyright 2018-2021,2022 Thomas E. Dickey *
	* Copyright 1998-2013,2017 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 *
	****************************************************************************/

	/*
	* alloc_entry.c -- allocation functions for terminfo entries
	*
	* _nc_copy_entry()
	* _nc_init_entry()
	* _nc_merge_entry()
	* _nc_save_str()
	* _nc_wrap_entry()
	*
	*/

	#include <curses.priv.h>

	#include <tic.h>

	MODULE_ID("$Id: alloc_entry.c,v 1.77 2022/10/15 19:37:33 tom Exp $")

	#define ABSENT_OFFSET -1
	#define CANCELLED_OFFSET -2

	static char stringbuf; / buffer for string capabilities */
	static size_t next_free; /* next free character in stringbuf */

	NCURSES_EXPORT(void)
	_nc_init_entry(ENTRY * const tp)
	/* initialize a terminal type data block */
	{
	DEBUG(2, (T_CALLED("_nc_init_entry(tp=%p)"), (void *) tp));

	if (tp == NULL) {
	#if NO_LEAKS
	if (stringbuf != NULL) {
	FreeAndNull(stringbuf);
	}
	return;
	#else
	_nc_err_abort("_nc_init_entry called without initialization");
	#endif
	}

	if (stringbuf == NULL)
	TYPE_CALLOC(char, (size_t) MAX_ENTRY_SIZE, stringbuf);

	next_free = 0;

	_nc_init_termtype(&(tp->tterm));

	DEBUG(2, (T_RETURN("")));
	}

	NCURSES_EXPORT(ENTRY *)
	_nc_copy_entry(ENTRY * oldp)
	{
	ENTRY *newp;

	DEBUG(2, (T_CALLED("_nc_copy_entry(oldp=%p)"), (void *) oldp));

	newp = typeCalloc(ENTRY, 1);
	if (newp != NULL) {
	newp = oldp;
	_nc_copy_termtype2(&(newp->tterm), &(oldp->tterm));
	}

	DEBUG(2, (T_RETURN("%p"), (void *) newp));
	return (newp);
	}

	/* save a copy of string in the string buffer */
	NCURSES_EXPORT(char *)
	_nc_save_str(const char *string)
	{
	char *result = 0;
	size_t old_next_free = next_free;

	if (stringbuf != NULL) {
	size_t len;

	if (!VALID_STRING(string))
	string = "";
	len = strlen(string) + 1;

	if (len == 1 && next_free != 0) {
	/*
	* Cheat a little by making an empty string point to the end of the
	* previous string.
	*/
	if (next_free < MAX_ENTRY_SIZE) {
	result = (stringbuf + next_free - 1);
	}
	} else if (next_free + len < MAX_ENTRY_SIZE) {
	_nc_STRCPY(&stringbuf[next_free], string, MAX_ENTRY_SIZE);
	DEBUG(7, ("Saved string %s", _nc_visbuf(string)));
	DEBUG(7, ("at location %d", (int) next_free));
	next_free += len;
	result = (stringbuf + old_next_free);
	} else {
	_nc_warning("Too much data, some is lost: %s", string);
	}
	}
	return result;
	}

	NCURSES_EXPORT(void)
	_nc_wrap_entry(ENTRY * const ep, bool copy_strings)
	/* copy the string parts to allocated storage, preserving pointers to it */
	{
	int offsets[MAX_ENTRY_SIZE / sizeof(short)];
	int useoffsets[MAX_USES];
	unsigned i, n;
	unsigned nuses;
	TERMTYPE2 *tp;

	DEBUG(2, (T_CALLED("_nc_wrap_entry(ep=%p, copy_strings=%d)"), (void *)
	ep, copy_strings));
	if (ep == NULL \|\| stringbuf == NULL)
	_nc_err_abort("_nc_wrap_entry called without initialization");

	nuses = ep->nuses;
	tp = &(ep->tterm);
	if (copy_strings) {
	next_free = 0; /* clear static storage */

	/* copy term_names, Strings, uses */
	tp->term_names = _nc_save_str(tp->term_names);
	for_each_string(i, tp) {
	if (tp->Strings[i] != ABSENT_STRING &&
	tp->Strings[i] != CANCELLED_STRING) {
	tp->Strings[i] = _nc_save_str(tp->Strings[i]);
	}
	}

	for (i = 0; i < nuses; i++) {
	if (ep->uses[i].name == 0) {
	ep->uses[i].name = _nc_save_str(ep->uses[i].name);
	}
	}

	free(tp->str_table);
	}

	assert(tp->term_names >= stringbuf);
	n = (unsigned) (tp->term_names - stringbuf);
	for_each_string(i, &(ep->tterm)) {
	if (i < SIZEOF(offsets)) {
	if (tp->Strings[i] == ABSENT_STRING) {
	offsets[i] = ABSENT_OFFSET;
	} else if (tp->Strings[i] == CANCELLED_STRING) {
	offsets[i] = CANCELLED_OFFSET;
	} else {
	offsets[i] = (int) (tp->Strings[i] - stringbuf);
	}
	}
	}

	for (i = 0; i < nuses; i++) {
	if (ep->uses[i].name == 0)
	useoffsets[i] = ABSENT_OFFSET;
	else
	useoffsets[i] = (int) (ep->uses[i].name - stringbuf);
	}

	TYPE_MALLOC(char, next_free, tp->str_table);
	(void) memcpy(tp->str_table, stringbuf, next_free);

	tp->term_names = tp->str_table + n;
	for_each_string(i, &(ep->tterm)) {
	if (i < SIZEOF(offsets)) {
	if (offsets[i] == ABSENT_OFFSET) {
	tp->Strings[i] = ABSENT_STRING;
	} else if (offsets[i] == CANCELLED_OFFSET) {
	tp->Strings[i] = CANCELLED_STRING;
	} else {
	tp->Strings[i] = tp->str_table + offsets[i];
	}
	}
	}

	#if NCURSES_XNAMES
	if (!copy_strings) {
	if ((n = (unsigned) NUM_EXT_NAMES(tp)) != 0) {
	if (n < SIZEOF(offsets)) {
	size_t length = 0;
	size_t offset;
	for (i = 0; i < n; i++) {
	length += strlen(tp->ext_Names[i]) + 1;
	offsets[i] = (int) (tp->ext_Names[i] - stringbuf);
	}
	TYPE_MALLOC(char, length, tp->ext_str_table);
	for (i = 0, offset = 0; i < n; i++) {
	tp->ext_Names[i] = tp->ext_str_table + offset;
	_nc_STRCPY(tp->ext_Names[i],
	stringbuf + offsets[i],
	length - offset);
	offset += strlen(tp->ext_Names[i]) + 1;
	}
	}
	}
	}
	#endif

	for (i = 0; i < nuses; i++) {
	if (useoffsets[i] == ABSENT_OFFSET) {
	ep->uses[i].name = 0;
	} else {
	ep->uses[i].name = strdup(tp->str_table + useoffsets[i]);
	}
	}
	DEBUG(2, (T_RETURN("")));
	}

	NCURSES_EXPORT(void)
	_nc_merge_entry(ENTRY * const target, ENTRY * const source)
	/* merge capabilities from `from' entry into `to' entry */
	{
	TERMTYPE2 *to = &(target->tterm);
	TERMTYPE2 *from = &(source->tterm);
	#if NCURSES_XNAMES
	TERMTYPE2 copy;
	size_t str_size;
	char *str_table;
	#endif
	unsigned i;

	if (source == 0 \|\| from == 0 \|\| target == 0 \|\| to == 0)
	return;

	#if NCURSES_XNAMES
	_nc_copy_termtype2(&copy, from);
	from = ©
	_nc_align_termtype(to, from);
	/*
	* compute the maximum size of the string-table.
	*/
	str_size = strlen(to->term_names) + 1;
	for_each_string(i, from) {
	if (VALID_STRING(from->Strings[i]))
	str_size += strlen(from->Strings[i]) + 1;
	}
	for_each_string(i, to) {
	if (VALID_STRING(to->Strings[i]))
	str_size += strlen(to->Strings[i]) + 1;
	}
	/* allocate a string-table large enough for both source/target, and
	* copy all of the strings into that table. In the merge, we will
	* select from the original source/target lists to construct a new
	* target list.
	*/
	if (str_size != 0) {
	char *str_copied;
	if ((str_table = malloc(str_size)) == NULL)
	_nc_err_abort(MSG_NO_MEMORY);
	str_copied = str_table;
	strcpy(str_copied, to->term_names);
	to->term_names = str_copied;
	str_copied += strlen(str_copied) + 1;
	for_each_string(i, from) {
	if (VALID_STRING(from->Strings[i])) {
	strcpy(str_copied, from->Strings[i]);
	from->Strings[i] = str_copied;
	str_copied += strlen(str_copied) + 1;
	}
	}
	for_each_string(i, to) {
	if (VALID_STRING(to->Strings[i])) {
	strcpy(str_copied, to->Strings[i]);
	to->Strings[i] = str_copied;
	str_copied += strlen(str_copied) + 1;
	}
	}
	free(to->str_table);
	to->str_table = str_table;
	free(from->str_table);
	}
	/*
	* Do the same for the extended-strings (i.e., lists of capabilities).
	*/
	str_size = 0;
	for (i = 0; i < NUM_EXT_NAMES(from); ++i) {
	if (VALID_STRING(from->ext_Names[i]))
	str_size += strlen(from->ext_Names[i]) + 1;
	}
	for (i = 0; i < NUM_EXT_NAMES(to); ++i) {
	if (VALID_STRING(to->ext_Names[i]))
	str_size += strlen(to->ext_Names[i]) + 1;
	}
	/* allocate a string-table large enough for both source/target, and
	* copy all of the strings into that table. In the merge, we will
	* select from the original source/target lists to construct a new
	* target list.
	*/
	if (str_size != 0) {
	char *str_copied;
	if ((str_table = malloc(str_size)) == NULL)
	_nc_err_abort(MSG_NO_MEMORY);
	str_copied = str_table;
	for (i = 0; i < NUM_EXT_NAMES(from); ++i) {
	if (VALID_STRING(from->ext_Names[i])) {
	strcpy(str_copied, from->ext_Names[i]);
	from->ext_Names[i] = str_copied;
	str_copied += strlen(str_copied) + 1;
	}
	}
	for (i = 0; i < NUM_EXT_NAMES(to); ++i) {
	if (VALID_STRING(to->ext_Names[i])) {
	strcpy(str_copied, to->ext_Names[i]);
	to->ext_Names[i] = str_copied;
	str_copied += strlen(str_copied) + 1;
	}
	}
	free(to->ext_str_table);
	to->ext_str_table = str_table;
	free(from->ext_str_table);
	}
	#endif
	for_each_boolean(i, from) {
	if (to->Booleans[i] != (NCURSES_SBOOL) CANCELLED_BOOLEAN) {
	int mergebool = from->Booleans[i];

	if (mergebool == CANCELLED_BOOLEAN)
	to->Booleans[i] = FALSE;
	else if (mergebool == TRUE)
	to->Booleans[i] = (NCURSES_SBOOL) mergebool;
	}
	}

	for_each_number(i, from) {
	if (to->Numbers[i] != CANCELLED_NUMERIC) {
	int mergenum = from->Numbers[i];

	if (mergenum == CANCELLED_NUMERIC)
	to->Numbers[i] = ABSENT_NUMERIC;
	else if (mergenum != ABSENT_NUMERIC)
	to->Numbers[i] = (NCURSES_INT2) mergenum;
	}
	}

	/*
	* Note: the copies of strings this makes don't have their own
	* storage. This is OK right now, but will be a problem if we
	* we ever want to deallocate entries.
	*/
	for_each_string(i, from) {
	if (to->Strings[i] != CANCELLED_STRING) {
	char *mergestring = from->Strings[i];

	if (mergestring == CANCELLED_STRING)
	to->Strings[i] = ABSENT_STRING;
	else if (mergestring != ABSENT_STRING)
	to->Strings[i] = mergestring;
	}
	}
	#if NCURSES_XNAMES
	/* cleanup */
	free(copy.Booleans);
	free(copy.Numbers);
	free(copy.Strings);
	free(copy.ext_Names);
	#endif
	}

	#if NO_LEAKS
	NCURSES_EXPORT(void)
	_nc_alloc_entry_leaks(void)
	{
	if (stringbuf != NULL) {
	FreeAndNull(stringbuf);
	}
	next_free = 0;
	}
	#endif