Commit b7cf37bc authored by Birte Kristina Friesel's avatar Birte Kristina Friesel
Browse files

Fix segfault in feh_event_handle_keypress for certain key inputs 

Turns out that it is undefined behaviour to pass a value to isctype functions
which does not fit inside a char. Closes #312
parent 0c5ed692

src/keyevents.c

+11 −2
Original line number Diff line number Diff line
@@ -42,6 +42,15 @@ static void feh_set_kb(fehkey *key, unsigned int s0, unsigned int y0, unsigned 
	key->keysyms[2] = y2;

}



static inline int ignore_space(int keysym) {

	/*

	 * Passing values which do not find inside a signed 8bit char to isprint,

	 * isspace and the likes is undefined behaviour... which glibc (for some

	 * values) implements as a segmentation fault. So let's not do that.

	 */

	return ((keysym <= 127) && (keysym >= -128) && isprint(keysym) && !isspace(keysym));

}



static void feh_set_parse_kb_partial(fehkey *key, int index, char *ks) {

	char *cur = ks;

	int mod = 0;
@@ -73,7 +82,7 @@ static void feh_set_parse_kb_partial(fehkey *key, int index, char *ks) { 
	}



	key->keysyms[index] = XStringToKeysym(cur);

	if (isprint(key->keysyms[index]) && !isspace(key->keysyms[index]))

	if (ignore_space(key->keysyms[index]))

		mod &= ~ShiftMask;

	key->keystates[index] = mod;
@@ -278,7 +287,7 @@ void feh_event_handle_keypress(XEvent * ev) 
	XLookupString(&ev->xkey, (char *) kbuf, sizeof(kbuf), &keysym, NULL);

	state = kev->state & (ControlMask | ShiftMask | Mod1Mask | Mod4Mask);



	if (isprint(keysym) && !isspace(keysym))

	if (ignore_space(keysym))

		state &= ~ShiftMask;



	/* menus are showing, so this is a menu control keypress */