strdup()s and other fixes/suggestions

[Jared Yanovich <jjy2+@pitt.edu>]

I believe most of the following are correct. Please let me know of any
that aren't. Sorry in advance to anyone's time I waste over incorrect
observations.

lib/libcurses/tinfo/comp_hash.c, revision 1.6 contains:

266:		name_table[n].nte_name = strdup(list[column]);

and it doesn't seem to be checked:
282:	_nc_make_hash_table(name_table, hash_table);

_nc_make_hash_table(table, hash_table):
81:	    hashvalue = hash_function(table[i].nte_name);

hash_function(string):
113:	while (*string) {

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sbin/init/init.c, revision 1.33 contains:

920:		sp->se_window = strdup(typ->ty_window);
921:		sp->se_window_argv = construct_argv(sp->se_window);

(in construct_argv(char *command)):
825:	char **argv = (char **) malloc(((strlen(command) + 1) / 2 + 1)

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sbin/mount/mount.c, revision 1.33 contains:

free(NULL):
675:	if (s0)
676:		free(s0);

uncasted malloc():
665:	char *cp;
...
669:		if ((cp = malloc(i)) == NULL)

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sbin/ping6/ping6.c, revision 1.56 may report a usage error when it runs
out of memory:
588:		target = nigroup(argv[argc - 1]);
589:		if (target == NULL) {
590:			usage();

because nigroup(name) may end with:
2672:	return strdup(hbuf);

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usr.bin/column/column.c, revision 1.10 contains:

in input(fp):
285:		list[entries++] = strdup(buf);

Flow controls from input(stdin) or input(argv[i]) to c_columnate():
144:	for (chcnt = col = 0, lp = list;; ++lp) {
145:		chcnt += printf("%s", *lp);

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usr.bin/lex/flex.1, revision 1.13 contains:

932:    char *yycopy = strdup( yytext )

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usr.bin/rup/rup.c, revision 1.18 contains:

148:	rup_data[rup_data_idx].host = strdup(host);

which looks like it might turn into:
122:		return strcmp(d1->host, d2->host);

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usr.bin/sectok/cyberflex.c, revision 1.25 contains:

130:				s2 = strdup(s);
131:				s = getpass("Re-enter passphrase: ");
132:				if (strcmp(s, s2)) {

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usr.bin/talk/get_names.c, revision 1.13 contains:

95:	names = strdup(argv[1]);
96:	for (cp = names; *cp && !strchr("@:!.", *cp); cp++)

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usr.bin/tic/tic.c, revision 1.27 contains:

1042:	zero = strdup(zero);
1043:	CHECK_SGR(1, enter_standout_mode);

953:#define CHECK_SGR(num,name) check_sgr(tp, zero, num, name, #name)

in check_sgr(tp, zero, ...):
939:    if (test != 0) {
940:	if (PRESENT(cap)) {
...
945:	} else if (strcmp(test, zero)) {

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usr.bin/tn3270/sys_curses/system.c, revision 1.15 contains:

641:    keyname = strdup("/tmp/apiXXXXXXXXXX");
642:    if ((fd = mkstemp(keyname)) == -1) {

and:

647:    keyname = strdup(sockNAME);
...
693:    if (strlen(sockNAME) > (sizeof sockNAME-(10+strlen(keyname)))) {

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usr.bin/window/ttinit.c, revision 1.10 contains:

97:	wwterm = strdup(_nc_first_name(cur_term->type.term_names));
...
116:	for (tp = tt_tab; tp->tt_name != 0; tp++)
117:		if (strncmp(tp->tt_name, wwterm, tp->tt_len) == 0)

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usr.sbin/dhcp/dhclient/dhclient.c, revision 1.27 contains a typo?

1933:			error ("script_init:n no memory for environment
initialization");

------------------------------------------------------------------------

	- Jared