Do not interpret CSI ? u as DECRC

The kitty keyboard protocol docs recommend CSI ? u to query support for
that protocol, see https://sw.kovidgoyal.net/kitty/keyboard-protocol/

For better or worse, fish shell uses this query to work around bugs
in other terminals triggered by requesting that protocol via CSI = 5 u.

Unfortunately, st interprets CSI ? u as DECRC (restore cursor
position). reproduce with 'printf "\x1b[?u"; cat'.

fish could work around this by switching to the alternate screen
before running this query; but that might cause tearing on terminals
that don't support Synchronized Output. I'm not sure.

In the meantime, let's correct our parser.

This adds a redundant else-after-return, for consistency with the
surrounding code.

FAQ

@@ -2,12 +2,14 @@
 
 Use the excellent tool of [utmp](https://git.suckless.org/utmp/) for this task.
 
+
 ## Some _random program_ complains that st is unknown/not recognised/unsupported/whatever!
 
 It means that st doesn’t have any terminfo entry on your system. Chances are
 you did not `make install`. If you just want to test it without installing it,
 you can manually run `tic -sx st.info`.
 
+
 ## Nothing works, and nothing is said about an unknown terminal!
 
 * Some programs just assume they’re running in xterm i.e. they don’t rely on
@@ -15,6 +17,7 @@ you can manually run `tic -sx st.info`.
 * Some programs don’t complain about the lacking st description and default to
   another terminal. In that case see the question about terminfo.
 
+
 ## How do I scroll back up?
 
 * Using a terminal multiplexer.
@@ -23,10 +26,12 @@ you can manually run `tic -sx st.info`.
 * Using the excellent tool of [scroll](https://git.suckless.org/scroll/).
 * Using the scrollback [patch](https://st.suckless.org/patches/scrollback/).
 
+
 ## I would like to have utmp and/or scroll functionality by default
 
-You can add the absolute patch of both programs in your config.h
+You can add the absolute path of both programs in your config.h file. You only
-file. You only have to modify the value of utmp and scroll variables.
+have to modify the value of utmp and scroll variables.
+
 
 ## Why doesn't the Del key work in some programs?
 
@@ -83,12 +88,14 @@ If you are using zsh, then read the zsh FAQ
 
 Putting these lines into your .zshrc will fix the problems.
 
+
 ## How can I use meta in 8bit mode?
 
 St supports meta in 8bit mode, but the default terminfo entry doesn't
 use this capability. If you want it, you have to use the 'st-meta' value
 in TERM.
 
+
 ## I cannot compile st in OpenBSD
 
 OpenBSD lacks librt, despite it being mandatory in POSIX
@@ -97,6 +104,7 @@ If you want to compile st for OpenBSD you have to remove -lrt from config.mk, an
 st will compile without any loss of functionality, because all the functions are
 included in libc on this platform.
 
+
 ## The Backspace Case
 
 St is emulating the Linux way of handling backspace being delete and delete being
@@ -158,19 +166,60 @@ terminal users wants its backspace to be how he feels it:
 	[1] http://www.ibb.net/~anne/keyboard.html
 	[2] http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO-5.html
 
+
 ## But I really want the old grumpy behaviour of my terminal
 
 Apply [1].
 
 [1] https://st.suckless.org/patches/delkey
 
-## Why do images not work in st (in programs such as w3m)?
 
-This is a terrible hack that overdraws an image on top of the terminal emulator
+## Why do images not work in st using the w3m image hack?
-window. It also relies on a very specific way the terminal draws it's contents.
+
+w3mimg uses a hack that draws an image on top of the terminal emulator Drawable
+window. The hack relies on the terminal to use a single buffer to draw its
+contents directly.
+
+st uses double-buffered drawing so the image is quickly replaced and may show a
+short flicker effect.
+
+Below is a patch example to change st double-buffering to a single Drawable
+buffer.
+
+diff --git a/x.c b/x.c
+--- a/x.c
++++ b/x.c
+@@ -732,10 +732,6 @@ xresize(int col, int row)
+ 	win.tw = col * win.cw;
+ 	win.th = row * win.ch;
+ 
+-	XFreePixmap(xw.dpy, xw.buf);
+-	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
+-			DefaultDepth(xw.dpy, xw.scr));
+-	XftDrawChange(xw.draw, xw.buf);
+ 	xclear(0, 0, win.w, win.h);
+ 
+ 	/* resize to new width */
+@@ -1148,8 +1144,7 @@ xinit(int cols, int rows)
+ 	gcvalues.graphics_exposures = False;
+ 	dc.gc = XCreateGC(xw.dpy, parent, GCGraphicsExposures,
+ 			&gcvalues);
+-	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
+-			DefaultDepth(xw.dpy, xw.scr));
++	xw.buf = xw.win;
+ 	XSetForeground(xw.dpy, dc.gc, dc.col[defaultbg].pixel);
+ 	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
+ 
+@@ -1632,8 +1627,6 @@ xdrawline(Line line, int x1, int y1, int x2)
+ void
+ xfinishdraw(void)
+ {
+-	XCopyArea(xw.dpy, xw.buf, xw.win, dc.gc, 0, 0, win.w,
+-			win.h, 0, 0);
+ 	XSetForeground(xw.dpy, dc.gc,
+ 			dc.col[IS_SET(MODE_REVERSE)?
+ 				defaultfg : defaultbg].pixel);
 
-A more proper (but limited way) would be using sixels. Which st doesn't
-support.
 
 ## BadLength X error in Xft when trying to render emoji
 
@@ -199,3 +248,6 @@ fonts:
 
 Please don't bother reporting this bug to st, but notify the upstream Xft
 developers about fixing this bug.
+
+As of 2022-09-05 this now seems to be finally fixed in libXft 2.3.5:
+https://gitlab.freedesktop.org/xorg/lib/libxft/-/blob/libXft-2.3.5/NEWS

LICENSE

@@ -1,6 +1,6 @@
 MIT/X Consortium License
 
-© 2014-2018 Hiltjo Posthuma <hiltjo at codemadness dot org>
+© 2014-2022 Hiltjo Posthuma <hiltjo at codemadness dot org>
 © 2018 Devin J. Pohly <djpohly at gmail dot com>
 © 2014-2017 Quentin Rameau <quinq at fifth dot space>
 © 2009-2012 Aurélien APTEL <aurelien dot aptel at gmail dot com>

Makefile

@@ -7,13 +7,7 @@ include config.mk
 SRC = st.c x.c
 OBJ = $(SRC:.c=.o)
 
-all: options st
+all: st
-
-options:
-	@echo st build options:
-	@echo "CFLAGS  = $(STCFLAGS)"
-	@echo "LDFLAGS = $(STLDFLAGS)"
-	@echo "CC      = $(CC)"
 
 config.h:
 	cp config.def.h config.h
@@ -54,4 +48,4 @@ uninstall:
 	rm -f $(DESTDIR)$(PREFIX)/bin/st
 	rm -f $(DESTDIR)$(MANPREFIX)/man1/st.1
 
-.PHONY: all options clean dist install uninstall
+.PHONY: all clean dist install uninstall

config.def.h

@@ -43,9 +43,18 @@ static unsigned int tripleclicktimeout = 600;
 /* alt screens */
 int allowaltscreen = 1;
 
-/* frames per second st should at maximum draw to the screen */
+/* allow certain non-interactive (insecure) window operations such as:
-static unsigned int xfps = 120;
+   setting the clipboard text */
-static unsigned int actionfps = 30;
+int allowwindowops = 0;
+
+/*
+ * draw latency range in ms - from new content/keypress/etc until drawing.
+ * within this range, st draws when content stops arriving (idle). mostly it's
+ * near minlatency, but it waits longer for slow updates to avoid partial draw.
+ * low minlatency will tear/flicker more, as it can "detect" idle too early.
+ */
+static double minlatency = 2;
+static double maxlatency = 33;
 
 /*
  * blinking timeout (set to 0 to disable blinking) for the terminal blinking
@@ -111,6 +120,8 @@ static const char *colorname[] = {
 	/* more colors can be added after 255 to use with DefaultXX */
 	"#cccccc",
 	"#555555",
+	"gray90", /* default foreground colour */
+	"black", /* default background colour */
 };
 
 
@@ -118,9 +129,9 @@ static const char *colorname[] = {
  * Default colors (colorname index)
  * foreground, background, cursor, reverse cursor
  */
-unsigned int defaultfg = 7;
+unsigned int defaultfg = 258;
-unsigned int defaultbg = 0;
+unsigned int defaultbg = 259;
-static unsigned int defaultcs = 256;
+unsigned int defaultcs = 256;
 static unsigned int defaultrcs = 257;
 
 /*
@@ -166,7 +177,9 @@ static uint forcemousemod = ShiftMask;
 static MouseShortcut mshortcuts[] = {
 	/* mask                 button   function        argument       release */
 	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},      1 },
+	{ ShiftMask,            Button4, ttysend,        {.s = "\033[5;2~"} },
 	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },
+	{ ShiftMask,            Button5, ttysend,        {.s = "\033[6;2~"} },
 	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\005"} },
 };
 

config.mk

@@ -1,5 +1,5 @@
 # st version
-VERSION = 0.8.3
+VERSION = 0.9.2
 
 # Customize below to fit your system
 
@@ -28,8 +28,9 @@ STLDFLAGS = $(LIBS) $(LDFLAGS)
 # OpenBSD:
 #CPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
 #LIBS = -L$(X11LIB) -lm -lX11 -lutil -lXft \
-#       `pkg-config --libs fontconfig` \
+#       `$(PKG_CONFIG) --libs fontconfig` \
-#       `pkg-config --libs freetype2`
+#       `$(PKG_CONFIG) --libs freetype2`
+#MANPREFIX = ${PREFIX}/man
 
 # compiler and linker
 # CC = c99

st.c

@@ -38,7 +38,7 @@
 
 /* macros */
 #define IS_SET(flag)		((term.mode & (flag)) != 0)
-#define ISCONTROLC0(c)		(BETWEEN(c, 0, 0x1f) || (c) == '\177')
+#define ISCONTROLC0(c)		(BETWEEN(c, 0, 0x1f) || (c) == 0x7f)
 #define ISCONTROLC1(c)		(BETWEEN(c, 0x80, 0x9f))
 #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
 #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
@@ -51,7 +51,6 @@ enum term_mode {
 	MODE_ECHO        = 1 << 4,
 	MODE_PRINT       = 1 << 5,
 	MODE_UTF8        = 1 << 6,
-	MODE_SIXEL       = 1 << 7,
 };
 
 enum cursor_movement {
@@ -78,12 +77,11 @@ enum charset {
 enum escape_state {
 	ESC_START      = 1,
 	ESC_CSI        = 2,
-	ESC_STR        = 4,  /* OSC, PM, APC */
+	ESC_STR        = 4,  /* DCS, OSC, PM, APC */
 	ESC_ALTCHARSET = 8,
 	ESC_STR_END    = 16, /* a final string was encountered */
 	ESC_TEST       = 32, /* Enter in test mode */
 	ESC_UTF8       = 64,
-	ESC_DCS        =128,
 };
 
 typedef struct {
@@ -129,6 +127,7 @@ typedef struct {
 	int charset;  /* current charset */
 	int icharset; /* selected charset for sequence */
 	int *tabs;
+	Rune lastc;   /* last printed char outside of sequence, 0 if control */
 } Term;
 
 /* CSI Escape sequence structs */
@@ -162,6 +161,7 @@ static void csidump(void);
 static void csihandle(void);
 static void csiparse(void);
 static void csireset(void);
+static void osc_color_response(int, int, int);
 static int eschandle(uchar);
 static void strdump(void);
 static void strhandle(void);
@@ -187,18 +187,18 @@ static void tputc(Rune);
 static void treset(void);
 static void tscrollup(int, int);
 static void tscrolldown(int, int);
-static void tsetattr(int *, int);
+static void tsetattr(const int *, int);
-static void tsetchar(Rune, Glyph *, int, int);
+static void tsetchar(Rune, const Glyph *, int, int);
 static void tsetdirt(int, int);
 static void tsetscroll(int, int);
 static void tswapscreen(void);
-static void tsetmode(int, int, int *, int);
+static void tsetmode(int, int, const int *, int);
 static int twrite(const char *, int, int);
 static void tfulldirt(void);
 static void tcontrolcode(uchar );
 static void tdectest(char );
 static void tdefutf8(char);
-static int32_t tdefcolor(int *, int *, int);
+static int32_t tdefcolor(const int *, int *, int);
 static void tdeftran(char);
 static void tstrsequence(uchar);
 
@@ -227,10 +227,10 @@ static int iofd = 1;
 static int cmdfd;
 static pid_t pid;
 
-static uchar utfbyte[UTF_SIZ + 1] = {0x80,    0, 0xC0, 0xE0, 0xF0};
+static const uchar utfbyte[UTF_SIZ + 1] = {0x80,    0, 0xC0, 0xE0, 0xF0};
-static uchar utfmask[UTF_SIZ + 1] = {0xC0, 0x80, 0xE0, 0xF0, 0xF8};
+static const uchar utfmask[UTF_SIZ + 1] = {0xC0, 0x80, 0xE0, 0xF0, 0xF8};
-static Rune utfmin[UTF_SIZ + 1] = {       0,    0,  0x80,  0x800,  0x10000};
+static const Rune utfmin[UTF_SIZ + 1] = {       0,    0,  0x80,  0x800,  0x10000};
-static Rune utfmax[UTF_SIZ + 1] = {0x10FFFF, 0x7F, 0x7FF, 0xFFFF, 0x10FFFF};
+static const Rune utfmax[UTF_SIZ + 1] = {0x10FFFF, 0x7F, 0x7FF, 0xFFFF, 0x10FFFF};
 
 ssize_t
 xwrite(int fd, const char *s, size_t len)
@@ -270,12 +270,14 @@ xrealloc(void *p, size_t len)
 }
 
 char *
-xstrdup(char *s)
+xstrdup(const char *s)
 {
-	if ((s = strdup(s)) == NULL)
+	char *p;
+
+	if ((p = strdup(s)) == NULL)
 		die("strdup: %s\n", strerror(errno));
 
-	return s;
+	return p;
 }
 
 size_t
@@ -348,25 +350,10 @@ utf8validate(Rune *u, size_t i)
 	return i;
 }
 
-static const char base64_digits[] = {
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 62, 0, 0, 0,
-	63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 0, 0, 0, -1, 0, 0, 0, 0, 1,
-	2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
-	22, 23, 24, 25, 0, 0, 0, 0, 0, 0, 26, 27, 28, 29, 30, 31, 32, 33, 34,
-	35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
-};
-
 char
 base64dec_getc(const char **src)
 {
-	while (**src && !isprint(**src))
+	while (**src && !isprint((unsigned char)**src))
 		(*src)++;
 	return **src ? *((*src)++) : '=';  /* emulate padding if string ends */
 }
@@ -376,6 +363,13 @@ base64dec(const char *src)
 {
 	size_t in_len = strlen(src);
 	char *result, *dst;
+	static const char base64_digits[256] = {
+		[43] = 62, 0, 0, 0, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
+		0, 0, 0, -1, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
+		13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 0, 0, 0, 0,
+		0, 0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
+		40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51
+	};
 
 	if (in_len % 4)
 		in_len += 4 - (in_len % 4);
@@ -519,7 +513,7 @@ selsnap(int *x, int *y, int direction)
 {
 	int newx, newy, xt, yt;
 	int delim, prevdelim;
-	Glyph *gp, *prevgp;
+	const Glyph *gp, *prevgp;
 
 	switch (sel.snap) {
 	case SNAP_WORD:
@@ -592,7 +586,7 @@ getsel(void)
 {
 	char *str, *ptr;
 	int y, bufsize, lastx, linelen;
-	Glyph *gp, *last;
+	const Glyph *gp, *last;
 
 	if (sel.ob.x == -1)
 		return NULL;
@@ -634,7 +628,8 @@ getsel(void)
 		 * st.
 		 * FIXME: Fix the computer world.
 		 */
-		if ((y < sel.ne.y || lastx >= linelen) && !(last->mode & ATTR_WRAP))
+		if ((y < sel.ne.y || lastx >= linelen) &&
+		    (!(last->mode & ATTR_WRAP) || sel.type == SEL_RECTANGULAR))
 			*ptr++ = '\n';
 	}
 	*ptr = 0;
@@ -730,7 +725,7 @@ sigchld(int a)
 		die("child exited with status %d\n", WEXITSTATUS(stat));
 	else if (WIFSIGNALED(stat))
 		die("child terminated due to signal %d\n", WTERMSIG(stat));
-	exit(0);
+	_exit(0);
 }
 
 void
@@ -758,7 +753,7 @@ stty(char **args)
 }
 
 int
-ttynew(char *line, char *cmd, char *out, char **args)
+ttynew(const char *line, char *cmd, const char *out, char **args)
 {
 	int m, s;
 
@@ -791,14 +786,15 @@ ttynew(char *line, char *cmd, char *out, char **args)
 		break;
 	case 0:
 		close(iofd);
+		close(m);
 		setsid(); /* create a new process group */
 		dup2(s, 0);
 		dup2(s, 1);
 		dup2(s, 2);
 		if (ioctl(s, TIOCSCTTY, NULL) < 0)
 			die("ioctl TIOCSCTTY failed: %s\n", strerror(errno));
+		if (s > 2)
 			close(s);
-		close(m);
 #ifdef __OpenBSD__
 		if (pledge("stdio getpw proc exec", NULL) == -1)
 			die("pledge\n");
@@ -841,7 +837,6 @@ ttyread(void)
 		if (buflen > 0)
 			memmove(buf, buf + written, buflen);
 		return ret;
-
 	}
 }
 
@@ -944,7 +939,7 @@ ttyresize(int tw, int th)
 }
 
 void
-ttyhangup()
+ttyhangup(void)
 {
 	/* Send SIGHUP to shell */
 	kill(pid, SIGHUP);
@@ -1102,32 +1097,22 @@ tscrollup(int orig, int n)
 void
 selscroll(int orig, int n)
 {
-	if (sel.ob.x == -1)
+	if (sel.ob.x == -1 || sel.alt != IS_SET(MODE_ALTSCREEN))
 		return;
 
-	if (BETWEEN(sel.ob.y, orig, term.bot) || BETWEEN(sel.oe.y, orig, term.bot)) {
+	if (BETWEEN(sel.nb.y, orig, term.bot) != BETWEEN(sel.ne.y, orig, term.bot)) {
-		if ((sel.ob.y += n) > term.bot || (sel.oe.y += n) < term.top) {
+		selclear();
+	} else if (BETWEEN(sel.nb.y, orig, term.bot)) {
+		sel.ob.y += n;
+		sel.oe.y += n;
+		if (sel.ob.y < term.top || sel.ob.y > term.bot ||
+		    sel.oe.y < term.top || sel.oe.y > term.bot) {
 			selclear();
-			return;
-		}
-		if (sel.type == SEL_RECTANGULAR) {
-			if (sel.ob.y < term.top)
-				sel.ob.y = term.top;
-			if (sel.oe.y > term.bot)
-				sel.oe.y = term.bot;
 		} else {
-			if (sel.ob.y < term.top) {
-				sel.ob.y = term.top;
-				sel.ob.x = 0;
-			}
-			if (sel.oe.y > term.bot) {
-				sel.oe.y = term.bot;
-				sel.oe.x = term.col;
-			}
-		}
 			selnormalize();
 		}
 	}
+}
 
 void
 tnewline(int first_col)
@@ -1147,6 +1132,7 @@ csiparse(void)
 {
 	char *p = csiescseq.buf, *np;
 	long int v;
+	int sep = ';'; /* colon or semi-colon, but not both */
 
 	csiescseq.narg = 0;
 	if (*p == '?') {
@@ -1164,7 +1150,9 @@ csiparse(void)
 			v = -1;
 		csiescseq.arg[csiescseq.narg++] = v;
 		p = np;
-		if (*p != ';' || csiescseq.narg == ESC_ARG_SIZ)
+		if (sep == ';' && *p == ':')
+			sep = ':'; /* allow override to colon once */
+		if (*p != sep || csiescseq.narg == ESC_ARG_SIZ)
 			break;
 		p++;
 	}
@@ -1197,9 +1185,9 @@ tmoveto(int x, int y)
 }
 
 void
-tsetchar(Rune u, Glyph *attr, int x, int y)
+tsetchar(Rune u, const Glyph *attr, int x, int y)
 {
-	static char *vt100_0[62] = { /* 0x41 - 0x7e */
+	static const char *vt100_0[62] = { /* 0x41 - 0x7e */
 		"↑", "↓", "→", "←", "█", "▚", "☃", /* A - G */
 		0, 0, 0, 0, 0, 0, 0, 0, /* H - O */
 		0, 0, 0, 0, 0, 0, 0, 0, /* P - W */
@@ -1311,7 +1299,7 @@ tdeleteline(int n)
 }
 
 int32_t
-tdefcolor(int *attr, int *npar, int l)
+tdefcolor(const int *attr, int *npar, int l)
 {
 	int32_t idx = -1;
 	uint r, g, b;
@@ -1361,7 +1349,7 @@ tdefcolor(int *attr, int *npar, int l)
 }
 
 void
-tsetattr(int *attr, int l)
+tsetattr(const int *attr, int l)
 {
 	int i;
 	int32_t idx;
@@ -1479,9 +1467,9 @@ tsetscroll(int t, int b)
 }
 
 void
-tsetmode(int priv, int set, int *args, int narg)
+tsetmode(int priv, int set, const int *args, int narg)
 {
-	int alt, *lim;
+	int alt; const int *lim;
 
 	for (lim = args + narg; args < lim; ++args) {
 		if (priv) {
@@ -1657,6 +1645,12 @@ csihandle(void)
 		if (csiescseq.arg[0] == 0)
 			ttywrite(vtiden, strlen(vtiden), 0);
 		break;
+	case 'b': /* REP -- if last char is printable print it <n> more times */
+		LIMIT(csiescseq.arg[0], 1, 65535);
+		if (term.lastc)
+			while (csiescseq.arg[0]-- > 0)
+				tputc(term.lastc);
+		break;
 	case 'C': /* CUF -- Cursor <n> Forward */
 	case 'a': /* HPR -- Cursor <n> Forward */
 		DEFAULT(csiescseq.arg[0], 1);
@@ -1711,7 +1705,7 @@ csihandle(void)
 			}
 			break;
 		case 1: /* above */
-			if (term.c.y > 1)
+			if (term.c.y > 0)
 				tclearregion(0, 0, term.col-1, term.c.y-1);
 			tclearregion(0, term.c.y, term.c.x, term.c.y);
 			break;
@@ -1737,6 +1731,7 @@ csihandle(void)
 		}
 		break;
 	case 'S': /* SU -- Scroll <n> line up */
+		if (csiescseq.priv) break;
 		DEFAULT(csiescseq.arg[0], 1);
 		tscrollup(term.top, csiescseq.arg[0]);
 		break;
@@ -1778,11 +1773,18 @@ csihandle(void)
 	case 'm': /* SGR -- Terminal attribute (color) */
 		tsetattr(csiescseq.arg, csiescseq.narg);
 		break;
-	case 'n': /* DSR – Device Status Report (cursor position) */
+	case 'n': /* DSR -- Device Status Report */
-		if (csiescseq.arg[0] == 6) {
+		switch (csiescseq.arg[0]) {
+		case 5: /* Status Report "OK" `0n` */
+			ttywrite("\033[0n", sizeof("\033[0n") - 1, 0);
+			break;
+		case 6: /* Report Cursor Position (CPR) "<row>;<column>R" */
 			len = snprintf(buf, sizeof(buf), "\033[%i;%iR",
 			               term.c.y+1, term.c.x+1);
 			ttywrite(buf, len, 0);
+			break;
+		default:
+			goto unknown;
 		}
 		break;
 	case 'r': /* DECSTBM -- Set Scrolling Region */
@@ -1799,7 +1801,11 @@ csihandle(void)
 		tcursor(CURSOR_SAVE);
 		break;
 	case 'u': /* DECRC -- Restore cursor position (ANSI.SYS) */
+		if (csiescseq.priv) {
+			goto unknown;
+		} else {
 			tcursor(CURSOR_LOAD);
+		}
 		break;
 	case ' ':
 		switch (csiescseq.mode[1]) {
@@ -1844,11 +1850,41 @@ csireset(void)
 	memset(&csiescseq, 0, sizeof(csiescseq));
 }
 
+void
+osc_color_response(int num, int index, int is_osc4)
+{
+	int n;
+	char buf[32];
+	unsigned char r, g, b;
+
+	if (xgetcolor(is_osc4 ? num : index, &r, &g, &b)) {
+		fprintf(stderr, "erresc: failed to fetch %s color %d\n",
+		        is_osc4 ? "osc4" : "osc",
+		        is_osc4 ? num : index);
+		return;
+	}
+
+	n = snprintf(buf, sizeof buf, "\033]%s%d;rgb:%02x%02x/%02x%02x/%02x%02x\007",
+	             is_osc4 ? "4;" : "", num, r, r, g, g, b, b);
+	if (n < 0 || n >= sizeof(buf)) {
+		fprintf(stderr, "error: %s while printing %s response\n",
+		        n < 0 ? "snprintf failed" : "truncation occurred",
+		        is_osc4 ? "osc4" : "osc");
+	} else {
+		ttywrite(buf, n, 1);
+	}
+}
+
 void
 strhandle(void)
 {
 	char *p = NULL, *dec;
 	int j, narg, par;
+	const struct { int idx; char *str; } osc_table[] = {
+		{ defaultfg, "foreground" },
+		{ defaultbg, "background" },
+		{ defaultcs, "cursor" }
+	};
 
 	term.esc &= ~(ESC_STR_END|ESC_STR);
 	strparse();
@@ -1858,13 +1894,21 @@ strhandle(void)
 	case ']': /* OSC -- Operating System Command */
 		switch (par) {
 		case 0:
+			if (narg > 1) {
+				xsettitle(strescseq.args[1]);
+				xseticontitle(strescseq.args[1]);
+			}
+			return;
 		case 1:
+			if (narg > 1)
+				xseticontitle(strescseq.args[1]);
+			return;
 		case 2:
 			if (narg > 1)
 				xsettitle(strescseq.args[1]);
 			return;
 		case 52:
-			if (narg > 2) {
+			if (narg > 2 && allowwindowops) {
 				dec = base64dec(strescseq.args[2]);
 				if (dec) {
 					xsetsel(dec);
@@ -1874,16 +1918,39 @@ strhandle(void)
 				}
 			}
 			return;
+		case 10:
+		case 11:
+		case 12:
+			if (narg < 2)
+				break;
+			p = strescseq.args[1];
+			if ((j = par - 10) < 0 || j >= LEN(osc_table))
+				break; /* shouldn't be possible */
+
+			if (!strcmp(p, "?")) {
+				osc_color_response(par, osc_table[j].idx, 0);
+			} else if (xsetcolorname(osc_table[j].idx, p)) {
+				fprintf(stderr, "erresc: invalid %s color: %s\n",
+				        osc_table[j].str, p);
+			} else {
+				tfulldirt();
+			}
+			return;
 		case 4: /* color set */
 			if (narg < 3)
 				break;
 			p = strescseq.args[2];
 			/* FALLTHROUGH */
-		case 104: /* color reset, here p = NULL */
+		case 104: /* color reset */
 			j = (narg > 1) ? atoi(strescseq.args[1]) : -1;
-			if (xsetcolorname(j, p)) {
+
-				if (par == 104 && narg <= 1)
+			if (p && !strcmp(p, "?")) {
+				osc_color_response(j, 0, 1);
+			} else if (xsetcolorname(j, p)) {
+				if (par == 104 && narg <= 1) {
+					xloadcols();
 					return; /* color reset without parameter */
+				}
 				fprintf(stderr, "erresc: invalid color j=%d, p=%s\n",
 				        j, p ? p : "(null)");
 			} else {
@@ -1891,7 +1958,7 @@ strhandle(void)
 				 * TODO if defaultbg color is changed, borders
 				 * are dirty
 				 */
-				redraw();
+				tfulldirt();
 			}
 			return;
 		}
@@ -1900,7 +1967,6 @@ strhandle(void)
 		xsettitle(strescseq.args[0]);
 		return;
 	case 'P': /* DCS -- Device Control String */
-		term.mode |= ESC_DCS;
 	case '_': /* APC -- Application Program Command */
 	case '^': /* PM -- Privacy Message */
 		return;
@@ -2018,7 +2084,7 @@ void
 tdumpline(int n)
 {
 	char buf[UTF_SIZ];
-	Glyph *bp, *end;
+	const Glyph *bp, *end;
 
 	bp = &term.line[n][0];
 	end = &bp[MIN(tlinelen(n), term.col) - 1];
@@ -2094,12 +2160,9 @@ tdectest(char c)
 void
 tstrsequence(uchar c)
 {
-	strreset();
-
 	switch (c) {
 	case 0x90:   /* DCS -- Device Control String */
 		c = 'P';
-		term.esc |= ESC_DCS;
 		break;
 	case 0x9f:   /* APC -- Application Program Command */
 		c = '_';
@@ -2111,6 +2174,7 @@ tstrsequence(uchar c)
 		c = ']';
 		break;
 	}
+	strreset();
 	strescseq.type = c;
 	term.esc |= ESC_STR;
 }
@@ -2153,6 +2217,7 @@ tcontrolcode(uchar ascii)
 		return;
 	case '\032': /* SUB */
 		tsetchar('?', &term.c.attr, term.c.x, term.c.y);
+		/* FALLTHROUGH */
 	case '\030': /* CAN */
 		csireset();
 		break;
@@ -2273,6 +2338,7 @@ eschandle(uchar ascii)
 		treset();
 		resettitle();
 		xloadcols();
+		xsetmode(0, MODE_HIDE);
 		break;
 	case '=': /* DECPAM -- Application keypad */
 		xsetmode(1, MODE_APPKEYPAD);
@@ -2307,16 +2373,14 @@ tputc(Rune u)
 	Glyph *gp;
 
 	control = ISCONTROL(u);
-	if (!IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
+	if (u < 127 || !IS_SET(MODE_UTF8)) {
 		c[0] = u;
 		width = len = 1;
 	} else {
 		len = utf8encode(u, c);
-		if (!control && (width = wcwidth(u)) == -1) {
+		if (!control && (width = wcwidth(u)) == -1)
-			memcpy(c, "\357\277\275", 4); /* UTF_INVALID */
 			width = 1;
 	}
-	}
 
 	if (IS_SET(MODE_PRINT))
 		tprinter(c, len);
@@ -2330,23 +2394,11 @@ tputc(Rune u)
 	if (term.esc & ESC_STR) {
 		if (u == '\a' || u == 030 || u == 032 || u == 033 ||
 		   ISCONTROLC1(u)) {
-			term.esc &= ~(ESC_START|ESC_STR|ESC_DCS);
+			term.esc &= ~(ESC_START|ESC_STR);
-			if (IS_SET(MODE_SIXEL)) {
-				/* TODO: render sixel */;
-				term.mode &= ~MODE_SIXEL;
-				return;
-			}
 			term.esc |= ESC_STR_END;
 			goto check_control_code;
 		}
 
-		if (IS_SET(MODE_SIXEL)) {
-			/* TODO: implement sixel mode */
-			return;
-		}
-		if (term.esc&ESC_DCS && strescseq.len == 0 && u == 'q')
-			term.mode |= MODE_SIXEL;
-
 		if (strescseq.len+len >= strescseq.siz) {
 			/*
 			 * Here is a bug in terminals. If the user never sends
@@ -2379,10 +2431,15 @@ check_control_code:
 	 * they must not cause conflicts with sequences.
 	 */
 	if (control) {
+		/* in UTF-8 mode ignore handling C1 control characters */
+		if (IS_SET(MODE_UTF8) && ISCONTROLC1(u))
+			return;
 		tcontrolcode(u);
 		/*
 		 * control codes are not shown ever
 		 */
+		if (!term.esc)
+			term.lastc = 0;
 		return;
 	} else if (term.esc & ESC_START) {
 		if (term.esc & ESC_CSI) {
@@ -2413,7 +2470,7 @@ check_control_code:
 		 */
 		return;
 	}
-	if (sel.ob.x != -1 && BETWEEN(term.c.y, sel.ob.y, sel.oe.y))
+	if (selected(term.c.x, term.c.y))
 		selclear();
 
 	gp = &term.line[term.c.y][term.c.x];
@@ -2423,19 +2480,29 @@ check_control_code:
 		gp = &term.line[term.c.y][term.c.x];
 	}
 
-	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col)
+	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col) {
 		memmove(gp+width, gp, (term.col - term.c.x - width) * sizeof(Glyph));
+		gp->mode &= ~ATTR_WIDE;
+	}
 
 	if (term.c.x+width > term.col) {
+		if (IS_SET(MODE_WRAP))
 			tnewline(1);
+		else
+			tmoveto(term.col - width, term.c.y);
 		gp = &term.line[term.c.y][term.c.x];
 	}
 
 	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
+	term.lastc = u;
 
 	if (width == 2) {
 		gp->mode |= ATTR_WIDE;
 		if (term.c.x+1 < term.col) {
+			if (gp[1].mode == ATTR_WIDE && term.c.x+2 < term.col) {
+				gp[2].u = ' ';
+				gp[2].mode &= ~ATTR_WDUMMY;
+			}
 			gp[1].u = '\0';
 			gp[1].mode = ATTR_WDUMMY;
 		}
@@ -2455,7 +2522,7 @@ twrite(const char *buf, int buflen, int show_ctrl)
 	int n;
 
 	for (n = 0; n < buflen; n += charsize) {
-		if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
+		if (IS_SET(MODE_UTF8)) {
 			/* process a complete utf8 char */
 			charsize = utf8decode(buf + n, &u, buflen - n);
 			if (charsize == 0)

st.h

@@ -91,7 +91,7 @@ void tnew(int, int);
 void tresize(int, int);
 void tsetdirtattr(int);
 void ttyhangup(void);
-int ttynew(char *, char *, char *, char **);
+int ttynew(const char *, char *, const char *, char **);
 size_t ttyread(void);
 void ttyresize(int, int);
 void ttywrite(const char *, size_t, int);
@@ -109,7 +109,7 @@ size_t utf8encode(Rune, char *);
 
 void *xmalloc(size_t);
 void *xrealloc(void *, size_t);
-char *xstrdup(char *);
+char *xstrdup(const char *);
 
 /* config.h globals */
 extern char *utmp;
@@ -118,7 +118,9 @@ extern char *stty_args;
 extern char *vtiden;
 extern wchar_t *worddelimiters;
 extern int allowaltscreen;
+extern int allowwindowops;
 extern char *termname;
 extern unsigned int tabspaces;
 extern unsigned int defaultfg;
 extern unsigned int defaultbg;
+extern unsigned int defaultcs;

st.info

@@ -158,6 +158,7 @@ st-mono| simpleterm monocolor,
 	rc=\E8,
 	rev=\E[7m,
 	ri=\EM,
+	rin=\E[%p1%dT,
 	ritm=\E[23m,
 	rmacs=\E(B,
 	rmcup=\E[?1049l,
@@ -183,6 +184,12 @@ st-mono| simpleterm monocolor,
 # XTerm extensions
 	rmxx=\E[29m,
 	smxx=\E[9m,
+	BE=\E[?2004h,
+	BD=\E[?2004l,
+	PS=\E[200~,
+	PE=\E[201~,
+# disabled rep for now: causes some issues with older ncurses versions.
+#	rep=%p1%c\E[%p2%{1}%-%db,
 # tmux extensions, see TERMINFO EXTENSIONS in tmux(1)
 	Tc,
 	Ms=\E]52;%p1%s;%p2%s\007,

win.h

@@ -30,6 +30,8 @@ void xdrawline(Line, int, int, int);
 void xfinishdraw(void);
 void xloadcols(void);
 int xsetcolorname(int, const char *);
+int xgetcolor(int, unsigned char *, unsigned char *, unsigned char *);
+void xseticontitle(char *);
 void xsettitle(char *);
 int xsetcursor(int);
 void xsetmode(int, unsigned int);

x.c

@@ -48,7 +48,7 @@ typedef struct {
 /* X modifiers */
 #define XK_ANY_MOD    UINT_MAX
 #define XK_NO_MOD     0
-#define XK_SWITCH_MOD (1<<13)
+#define XK_SWITCH_MOD (1<<13|1<<14)
 
 /* function definitions used in config.h */
 static void clipcopy(const Arg *);
@@ -93,7 +93,7 @@ typedef struct {
 	Window win;
 	Drawable buf;
 	GlyphFontSpec *specbuf; /* font spec buffer used for rendering */
-	Atom xembed, wmdeletewin, netwmname, netwmpid;
+	Atom xembed, wmdeletewin, netwmname, netwmiconname, netwmpid;
 	struct {
 		XIM xim;
 		XIC xic;
@@ -156,7 +156,7 @@ static void xresize(int, int);
 static void xhints(void);
 static int xloadcolor(int, const char *, Color *);
 static int xloadfont(Font *, FcPattern *);
-static void xloadfonts(char *, double);
+static void xloadfonts(const char *, double);
 static void xunloadfont(Font *);
 static void xunloadfonts(void);
 static void xsetenv(void);
@@ -252,7 +252,7 @@ static char *opt_line  = NULL;
 static char *opt_name  = NULL;
 static char *opt_title = NULL;
 
-static int oldbutton = 3; /* button event on startup: 3 = release */
+static uint buttons; /* bit field of pressed buttons */
 
 void
 clipcopy(const Arg *dummy)
@@ -364,59 +364,68 @@ mousesel(XEvent *e, int done)
 void
 mousereport(XEvent *e)
 {
-	int len, x = evcol(e), y = evrow(e),
+	int len, btn, code;
-	    button = e->xbutton.button, state = e->xbutton.state;
+	int x = evcol(e), y = evrow(e);
+	int state = e->xbutton.state;
 	char buf[40];
 	static int ox, oy;
 
-	/* from urxvt */
+	if (e->type == MotionNotify) {
-	if (e->xbutton.type == MotionNotify) {
 		if (x == ox && y == oy)
 			return;
 		if (!IS_SET(MODE_MOUSEMOTION) && !IS_SET(MODE_MOUSEMANY))
 			return;
-		/* MOUSE_MOTION: no reporting if no button is pressed */
+		/* MODE_MOUSEMOTION: no reporting if no button is pressed */
-		if (IS_SET(MODE_MOUSEMOTION) && oldbutton == 3)
+		if (IS_SET(MODE_MOUSEMOTION) && buttons == 0)
 			return;
-
+		/* Set btn to lowest-numbered pressed button, or 12 if no
-		button = oldbutton + 32;
+		 * buttons are pressed. */
-		ox = x;
+		for (btn = 1; btn <= 11 && !(buttons & (1<<(btn-1))); btn++)
-		oy = y;
+			;
+		code = 32;
 	} else {
-		if (!IS_SET(MODE_MOUSESGR) && e->xbutton.type == ButtonRelease) {
+		btn = e->xbutton.button;
-			button = 3;
+		/* Only buttons 1 through 11 can be encoded */
-		} else {
+		if (btn < 1 || btn > 11)
-			button -= Button1;
+			return;
-			if (button >= 3)
+		if (e->type == ButtonRelease) {
-				button += 64 - 3;
-		}
-		if (e->xbutton.type == ButtonPress) {
-			oldbutton = button;
-			ox = x;
-			oy = y;
-		} else if (e->xbutton.type == ButtonRelease) {
-			oldbutton = 3;
 			/* MODE_MOUSEX10: no button release reporting */
 			if (IS_SET(MODE_MOUSEX10))
 				return;
-			if (button == 64 || button == 65)
+			/* Don't send release events for the scroll wheel */
+			if (btn == 4 || btn == 5)
 				return;
 		}
+		code = 0;
 	}
 
+	ox = x;
+	oy = y;
+
+	/* Encode btn into code. If no button is pressed for a motion event in
+	 * MODE_MOUSEMANY, then encode it as a release. */
+	if ((!IS_SET(MODE_MOUSESGR) && e->type == ButtonRelease) || btn == 12)
+		code += 3;
+	else if (btn >= 8)
+		code += 128 + btn - 8;
+	else if (btn >= 4)
+		code += 64 + btn - 4;
+	else
+		code += btn - 1;
+
 	if (!IS_SET(MODE_MOUSEX10)) {
-		button += ((state & ShiftMask  ) ? 4  : 0)
+		code += ((state & ShiftMask  ) ?  4 : 0)
-			+ ((state & Mod4Mask   ) ? 8  : 0)
+		      + ((state & Mod1Mask   ) ?  8 : 0) /* meta key: alt */
 		      + ((state & ControlMask) ? 16 : 0);
 	}
 
 	if (IS_SET(MODE_MOUSESGR)) {
 		len = snprintf(buf, sizeof(buf), "\033[<%d;%d;%d%c",
-				button, x+1, y+1,
+				code, x+1, y+1,
-				e->xbutton.type == ButtonRelease ? 'm' : 'M');
+				e->type == ButtonRelease ? 'm' : 'M');
 	} else if (x < 223 && y < 223) {
 		len = snprintf(buf, sizeof(buf), "\033[M%c%c%c",
-				32+button, 32+x+1, 32+y+1);
+				32+code, 32+x+1, 32+y+1);
 	} else {
 		return;
 	}
@@ -459,9 +468,13 @@ mouseaction(XEvent *e, uint release)
 void
 bpress(XEvent *e)
 {
+	int btn = e->xbutton.button;
 	struct timespec now;
 	int snap;
 
+	if (1 <= btn && btn <= 11)
+		buttons |= 1 << (btn-1);
+
 	if (IS_SET(MODE_MOUSE) && !(e->xbutton.state & forcemousemod)) {
 		mousereport(e);
 		return;
@@ -470,7 +483,7 @@ bpress(XEvent *e)
 	if (mouseaction(e, 0))
 		return;
 
-	if (e->xbutton.button == Button1) {
+	if (btn == Button1) {
 		/*
 		 * If the user clicks below predefined timeouts specific
 		 * snapping behaviour is exposed.
@@ -684,6 +697,11 @@ xsetsel(char *str)
 void
 brelease(XEvent *e)
 {
+	int btn = e->xbutton.button;
+
+	if (1 <= btn && btn <= 11)
+		buttons &= ~(1 << (btn-1));
+
 	if (IS_SET(MODE_MOUSE) && !(e->xbutton.state & forcemousemod)) {
 		mousereport(e);
 		return;
@@ -691,7 +709,7 @@ brelease(XEvent *e)
 
 	if (mouseaction(e, 1))
 		return;
-	if (e->xbutton.button == Button1)
+	if (btn == Button1)
 		mousesel(e, 1);
 }
 
@@ -797,12 +815,25 @@ xloadcols(void)
 	loaded = 1;
 }
 
+int
+xgetcolor(int x, unsigned char *r, unsigned char *g, unsigned char *b)
+{
+	if (!BETWEEN(x, 0, dc.collen - 1))
+		return 1;
+
+	*r = dc.col[x].color.red >> 8;
+	*g = dc.col[x].color.green >> 8;
+	*b = dc.col[x].color.blue >> 8;
+
+	return 0;
+}
+
 int
 xsetcolorname(int x, const char *name)
 {
 	Color ncolor;
 
-	if (!BETWEEN(x, 0, dc.collen))
+	if (!BETWEEN(x, 0, dc.collen - 1))
 		return 1;
 
 	if (!xloadcolor(x, name, &ncolor))
@@ -950,7 +981,7 @@ xloadfont(Font *f, FcPattern *pattern)
 }
 
 void
-xloadfonts(char *fontstr, double fontsize)
+xloadfonts(const char *fontstr, double fontsize)
 {
 	FcPattern *pattern;
 	double fontval;
@@ -958,7 +989,7 @@ xloadfonts(char *fontstr, double fontsize)
 	if (fontstr[0] == '-')
 		pattern = XftXlfdParse(fontstr, False, False);
 	else
-		pattern = FcNameParse((FcChar8 *)fontstr);
+		pattern = FcNameParse((const FcChar8 *)fontstr);
 
 	if (!pattern)
 		die("can't open font %s\n", fontstr);
@@ -1100,7 +1131,7 @@ xinit(int cols, int rows)
 {
 	XGCValues gcvalues;
 	Cursor cursor;
-	Window parent;
+	Window parent, root;
 	pid_t thispid = getpid();
 	XColor xmousefg, xmousebg;
 
@@ -1137,16 +1168,19 @@ xinit(int cols, int rows)
 		| ButtonMotionMask | ButtonPressMask | ButtonReleaseMask;
 	xw.attrs.colormap = xw.cmap;
 
+	root = XRootWindow(xw.dpy, xw.scr);
 	if (!(opt_embed && (parent = strtol(opt_embed, NULL, 0))))
-		parent = XRootWindow(xw.dpy, xw.scr);
+		parent = root;
-	xw.win = XCreateWindow(xw.dpy, parent, xw.l, xw.t,
+	xw.win = XCreateWindow(xw.dpy, root, xw.l, xw.t,
 			win.w, win.h, 0, XDefaultDepth(xw.dpy, xw.scr), InputOutput,
 			xw.vis, CWBackPixel | CWBorderPixel | CWBitGravity
 			| CWEventMask | CWColormap, &xw.attrs);
+	if (parent != root)
+		XReparentWindow(xw.dpy, xw.win, parent, xw.l, xw.t);
 
 	memset(&gcvalues, 0, sizeof(gcvalues));
 	gcvalues.graphics_exposures = False;
-	dc.gc = XCreateGC(xw.dpy, parent, GCGraphicsExposures,
+	dc.gc = XCreateGC(xw.dpy, xw.win, GCGraphicsExposures,
 			&gcvalues);
 	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
 			DefaultDepth(xw.dpy, xw.scr));
@@ -1186,6 +1220,7 @@ xinit(int cols, int rows)
 	xw.xembed = XInternAtom(xw.dpy, "_XEMBED", False);
 	xw.wmdeletewin = XInternAtom(xw.dpy, "WM_DELETE_WINDOW", False);
 	xw.netwmname = XInternAtom(xw.dpy, "_NET_WM_NAME", False);
+	xw.netwmiconname = XInternAtom(xw.dpy, "_NET_WM_ICON_NAME", False);
 	XSetWMProtocols(xw.dpy, xw.win, &xw.wmdeletewin, 1);
 
 	xw.netwmpid = XInternAtom(xw.dpy, "_NET_WM_PID", False);
@@ -1461,12 +1496,12 @@ xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, i
 
 	/* Render underline and strikethrough. */
 	if (base.mode & ATTR_UNDERLINE) {
-		XftDrawRect(xw.draw, fg, winx, winy + dc.font.ascent + 1,
+		XftDrawRect(xw.draw, fg, winx, winy + dc.font.ascent * chscale + 1,
 				width, 1);
 	}
 
 	if (base.mode & ATTR_STRUCK) {
-		XftDrawRect(xw.draw, fg, winx, winy + 2 * dc.font.ascent / 3,
+		XftDrawRect(xw.draw, fg, winx, winy + 2 * dc.font.ascent * chscale / 3,
 				width, 1);
 	}
 
@@ -1526,8 +1561,9 @@ xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
 	/* draw the new one */
 	if (IS_SET(MODE_FOCUSED)) {
 		switch (win.cursor) {
-		case 7: /* st extension: snowman (U+2603) */
+		case 7: /* st extension */
-			g.u = 0x2603;
+			g.u = 0x2603; /* snowman (U+2603) */
+			/* FALLTHROUGH */
 		case 0: /* Blinking Block */
 		case 1: /* Blinking Block (Default) */
 		case 2: /* Steady Block */
@@ -1578,14 +1614,35 @@ xsetenv(void)
 	setenv("WINDOWID", buf, 1);
 }
 
+void
+xseticontitle(char *p)
+{
+	XTextProperty prop;
+	DEFAULT(p, opt_title);
+
+	if (p[0] == '\0')
+		p = opt_title;
+
+	if (Xutf8TextListToTextProperty(xw.dpy, &p, 1, XUTF8StringStyle,
+	                                &prop) != Success)
+		return;
+	XSetWMIconName(xw.dpy, xw.win, &prop);
+	XSetTextProperty(xw.dpy, xw.win, &prop, xw.netwmiconname);
+	XFree(prop.value);
+}
+
 void
 xsettitle(char *p)
 {
 	XTextProperty prop;
 	DEFAULT(p, opt_title);
 
-	Xutf8TextListToTextProperty(xw.dpy, &p, 1, XUTF8StringStyle,
+	if (p[0] == '\0')
-			&prop);
+		p = opt_title;
+
+	if (Xutf8TextListToTextProperty(xw.dpy, &p, 1, XUTF8StringStyle,
+	                                &prop) != Success)
+		return;
 	XSetWMName(xw.dpy, xw.win, &prop);
 	XSetTextProperty(xw.dpy, xw.win, &prop, xw.netwmname);
 	XFree(prop.value);
@@ -1689,8 +1746,7 @@ xsetmode(int set, unsigned int flags)
 int
 xsetcursor(int cursor)
 {
-	DEFAULT(cursor, 1);
+	if (!BETWEEN(cursor, 0, 7)) /* 7: st extension */
-	if (!BETWEEN(cursor, 0, 6))
 		return 1;
 	win.cursor = cursor;
 	return 0;
@@ -1786,7 +1842,7 @@ void
 kpress(XEvent *ev)
 {
 	XKeyEvent *e = &ev->xkey;
-	KeySym ksym;
+	KeySym ksym = NoSymbol;
 	char buf[64], *customkey;
 	int len;
 	Rune c;
@@ -1796,10 +1852,13 @@ kpress(XEvent *ev)
 	if (IS_SET(MODE_KBDLOCK))
 		return;
 
-	if (xw.ime.xic)
+	if (xw.ime.xic) {
 		len = XmbLookupString(xw.ime.xic, e, buf, sizeof buf, &ksym, &status);
-	else
+		if (status == XBufferOverflow)
+			return;
+	} else {
 		len = XLookupString(e, buf, sizeof buf, &ksym, NULL);
+	}
 	/* 1. shortcuts */
 	for (bp = shortcuts; bp < shortcuts + LEN(shortcuts); bp++) {
 		if (ksym == bp->keysym && match(bp->mod, e->state)) {
@@ -1867,10 +1926,9 @@ run(void)
 	XEvent ev;
 	int w = win.w, h = win.h;
 	fd_set rfd;
-	int xfd = XConnectionNumber(xw.dpy), xev, blinkset = 0, dodraw = 0;
+	int xfd = XConnectionNumber(xw.dpy), ttyfd, xev, drawing;
-	int ttyfd;
+	struct timespec seltv, *tv, now, lastblink, trigger;
-	struct timespec drawtimeout, *tv = NULL, now, last, lastblink;
+	double timeout;
-	long deltatime;
 
 	/* Waiting for window mapping */
 	do {
@@ -1891,51 +1949,31 @@ run(void)
 	ttyfd = ttynew(opt_line, shell, opt_io, opt_cmd);
 	cresize(w, h);
 
-	clock_gettime(CLOCK_MONOTONIC, &last);
+	for (timeout = -1, drawing = 0, lastblink = (struct timespec){0};;) {
-	lastblink = last;
-
-	for (xev = actionfps;;) {
 		FD_ZERO(&rfd);
 		FD_SET(ttyfd, &rfd);
 		FD_SET(xfd, &rfd);
 
+		if (XPending(xw.dpy))
+			timeout = 0;  /* existing events might not set xfd */
+
+		seltv.tv_sec = timeout / 1E3;
+		seltv.tv_nsec = 1E6 * (timeout - 1E3 * seltv.tv_sec);
+		tv = timeout >= 0 ? &seltv : NULL;
+
 		if (pselect(MAX(xfd, ttyfd)+1, &rfd, NULL, NULL, tv, NULL) < 0) {
 			if (errno == EINTR)
 				continue;
 			die("select failed: %s\n", strerror(errno));
 		}
-		if (FD_ISSET(ttyfd, &rfd)) {
-			ttyread();
-			if (blinktimeout) {
-				blinkset = tattrset(ATTR_BLINK);
-				if (!blinkset)
-					MODBIT(win.mode, 0, MODE_BLINK);
-			}
-		}
-
-		if (FD_ISSET(xfd, &rfd))
-			xev = actionfps;
-
 		clock_gettime(CLOCK_MONOTONIC, &now);
-		drawtimeout.tv_sec = 0;
-		drawtimeout.tv_nsec =  (1000 * 1E6)/ xfps;
-		tv = &drawtimeout;
 
-		dodraw = 0;
+		if (FD_ISSET(ttyfd, &rfd))
-		if (blinktimeout && TIMEDIFF(now, lastblink) > blinktimeout) {
+			ttyread();
-			tsetdirtattr(ATTR_BLINK);
-			win.mode ^= MODE_BLINK;
-			lastblink = now;
-			dodraw = 1;
-		}
-		deltatime = TIMEDIFF(now, last);
-		if (deltatime > 1000 / (xev ? xfps : actionfps)) {
-			dodraw = 1;
-			last = now;
-		}
 
-		if (dodraw) {
+		xev = 0;
 		while (XPending(xw.dpy)) {
+			xev = 1;
 			XNextEvent(xw.dpy, &ev);
 			if (XFilterEvent(&ev, None))
 				continue;
@@ -1943,30 +1981,45 @@ run(void)
 				(handler[ev.type])(&ev);
 		}
 
+		/*
+		 * To reduce flicker and tearing, when new content or event
+		 * triggers drawing, we first wait a bit to ensure we got
+		 * everything, and if nothing new arrives - we draw.
+		 * We start with trying to wait minlatency ms. If more content
+		 * arrives sooner, we retry with shorter and shorter periods,
+		 * and eventually draw even without idle after maxlatency ms.
+		 * Typically this results in low latency while interacting,
+		 * maximum latency intervals during `cat huge.txt`, and perfect
+		 * sync with periodic updates from animations/key-repeats/etc.
+		 */
+		if (FD_ISSET(ttyfd, &rfd) || xev) {
+			if (!drawing) {
+				trigger = now;
+				drawing = 1;
+			}
+			timeout = (maxlatency - TIMEDIFF(now, trigger)) \
+			          / maxlatency * minlatency;
+			if (timeout > 0)
+				continue;  /* we have time, try to find idle */
+		}
+
+		/* idle detected or maxlatency exhausted -> draw */
+		timeout = -1;
+		if (blinktimeout && tattrset(ATTR_BLINK)) {
+			timeout = blinktimeout - TIMEDIFF(now, lastblink);
+			if (timeout <= 0) {
+				if (-timeout > blinktimeout) /* start visible */
+					win.mode |= MODE_BLINK;
+				win.mode ^= MODE_BLINK;
+				tsetdirtattr(ATTR_BLINK);
+				lastblink = now;
+				timeout = blinktimeout;
+			}
+		}
+
 		draw();
 		XFlush(xw.dpy);
-
+		drawing = 0;
-			if (xev && !FD_ISSET(xfd, &rfd))
-				xev--;
-			if (!FD_ISSET(ttyfd, &rfd) && !FD_ISSET(xfd, &rfd)) {
-				if (blinkset) {
-					if (TIMEDIFF(now, lastblink) \
-							> blinktimeout) {
-						drawtimeout.tv_nsec = 1000;
-					} else {
-						drawtimeout.tv_nsec = (1E6 * \
-							(blinktimeout - \
-							TIMEDIFF(now,
-								lastblink)));
-					}
-					drawtimeout.tv_sec = \
-					    drawtimeout.tv_nsec / 1E9;
-					drawtimeout.tv_nsec %= (long)1E9;
-				} else {
-					tv = NULL;
-				}
-			}
-		}
 	}
 }
 
@@ -1988,7 +2041,7 @@ main(int argc, char *argv[])
 {
 	xw.l = xw.t = 0;
 	xw.isfixed = False;
-	win.cursor = cursorshape;
+	xsetcursor(cursorshape);
 
 	ARGBEGIN {
 	case 'a':