sfeed_curses

commit ea54b7b64b9a9c92108a2e1c680c426ca248e9cd
parent 8ebfb75d9ca26ce24a76aa3dc956182bd06f5b59
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Sun, 25 Jul 2021 14:36:53 +0200

check if capname is NULL for tparm()

POSIX also does not specify NULL is allowed or not, so assume it isn't.
	https://pubs.opengroup.org/onlinepubs/7908799/xcurses/tigetflag.html

This adds a wrapper to prevent NULL assertion in NetBSD curses/terminfo.

netbsd-curses can use a diagnostic assert and aborts the program:
	https://github.com/oasislinux/netbsd-curses/blob/5b78297a1276a7d64c3be78d1e54251a1203a44a/lib/libterminfo/tparm.c
	http://cvsweb.netbsd.org/bsdweb.cgi/~checkout~/src/lib/libterminfo/tparm.c?rev=1.18&content-type=text/plain&only_with_tag=MAIN

The current ncurses snapshot can show a trace call when the parameter is NULL,
see the tparm_setup() function:
	https://github.com/ThomasDickey/ncurses-snapshots/blob/master/ncurses/tinfo/lib_tparm.c

OpenBSD ncurses (older version), tparam_internal function does nothing if the parameter is NULL:
	http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/lib/libcurses/tinfo/lib_tparm.c?rev=1.9&content-type=text/plain

Noticed on Oasis Linux which uses netbsd-curses and aborts when used in the
terminal with the default $TERM=linux .

Diffstat:
M
sfeed_curses.c
 | 
32
+++++++++++++++++++++-----------

1 file changed, 21 insertions(+), 11 deletions(-)
diff --git a/sfeed_curses.c b/sfeed_curses.c
@@ -272,6 +272,16 @@ estrdup(const char *s)
 	return p;
 }
 
+/* wrapper for tparm which allows NULL parameter for str. */
+char *
+tparmnull(const char *str, long p1, long p2, long p3, long p4, long p5,
+          long p6, long p7, long p8, long p9)
+{
+	if (!str)
+		return NULL;
+	return tparm(str, p1, p2, p3, p4, p5, p6, p7, p8, p9);
+}
+
 /* strcasestr() included for portability */
 #undef strcasestr
 char *
@@ -508,7 +518,7 @@ updatetitle(void)
 void
 appmode(int on)
 {
-	ttywrite(tparm(on ? enter_ca_mode : exit_ca_mode, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+	ttywrite(tparmnull(on ? enter_ca_mode : exit_ca_mode, 0, 0, 0, 0, 0, 0, 0, 0, 0));
 }
 
 void
@@ -521,13 +531,13 @@ mousemode(int on)
 void
 cursormode(int on)
 {
-	ttywrite(tparm(on ? cursor_normal : cursor_invisible, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+	ttywrite(tparmnull(on ? cursor_normal : cursor_invisible, 0, 0, 0, 0, 0, 0, 0, 0, 0));
 }
 
 void
 cursormove(int x, int y)
 {
-	ttywrite(tparm(cursor_address, y, x, 0, 0, 0, 0, 0, 0, 0));
+	ttywrite(tparmnull(cursor_address, y, x, 0, 0, 0, 0, 0, 0, 0));
 }
 
 void
@@ -535,7 +545,7 @@ cursorsave(void)
 {
 	/* do not save the cursor if it won't be restored anyway */
 	if (cursor_invisible)
-		ttywrite(tparm(save_cursor, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+		ttywrite(tparmnull(save_cursor, 0, 0, 0, 0, 0, 0, 0, 0, 0));
 }
 
 void
@@ -543,7 +553,7 @@ cursorrestore(void)
 {
 	/* if the cursor cannot be hidden then move to a consistent position */
 	if (cursor_invisible)
-		ttywrite(tparm(restore_cursor, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+		ttywrite(tparmnull(restore_cursor, 0, 0, 0, 0, 0, 0, 0, 0, 0));
 	else
 		cursormove(0, 0);
 }
@@ -553,16 +563,16 @@ attrmode(int mode)
 {
 	switch (mode) {
 	case ATTR_RESET:
-		ttywrite(tparm(exit_attribute_mode, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+		ttywrite(tparmnull(exit_attribute_mode, 0, 0, 0, 0, 0, 0, 0, 0, 0));
 		break;
 	case ATTR_BOLD_ON:
-		ttywrite(tparm(enter_bold_mode, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+		ttywrite(tparmnull(enter_bold_mode, 0, 0, 0, 0, 0, 0, 0, 0, 0));
 		break;
 	case ATTR_FAINT_ON:
-		ttywrite(tparm(enter_dim_mode, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+		ttywrite(tparmnull(enter_dim_mode, 0, 0, 0, 0, 0, 0, 0, 0, 0));
 		break;
 	case ATTR_REVERSE_ON:
-		ttywrite(tparm(enter_reverse_mode, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+		ttywrite(tparmnull(enter_reverse_mode, 0, 0, 0, 0, 0, 0, 0, 0, 0));
 		break;
 	default:
 		break;
@@ -572,13 +582,13 @@ attrmode(int mode)
 void
 cleareol(void)
 {
-	ttywrite(tparm(clr_eol, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+	ttywrite(tparmnull(clr_eol, 0, 0, 0, 0, 0, 0, 0, 0, 0));
 }
 
 void
 clearscreen(void)
 {
-	ttywrite(tparm(clear_screen, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+	ttywrite(tparmnull(clear_screen, 0, 0, 0, 0, 0, 0, 0, 0, 0));
 }
 
 void