Applied scrollback patches

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
-file. You only have to modify the value of utmp and scroll variables.
+You can add the absolute path of both programs in your config.h file. You only
+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
-window. It also relies on a very specific way the terminal draws it's contents.
+## Why do images not work in st using the w3m image hack?
+
+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
-
-options:
-	@echo st build options:
-	@echo "CFLAGS  = $(STCFLAGS)"
-	@echo "LDFLAGS = $(STLDFLAGS)"
-	@echo "CC      = $(CC)"
+all: st
 
 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 */
-static unsigned int xfps = 120;
-static unsigned int actionfps = 30;
+/* allow certain non-interactive (insecure) window operations such as:
+   setting the clipboard text */
+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 defaultbg = 0;
-static unsigned int defaultcs = 256;
+unsigned int defaultfg = 258;
+unsigned int defaultbg = 259;
+unsigned int defaultcs = 256;
 static unsigned int defaultrcs = 257;
 
 /*
@@ -165,8 +176,12 @@ static uint forcemousemod = ShiftMask;
  */
 static MouseShortcut mshortcuts[] = {
 	/* mask                 button   function        argument       release */
+	{ ShiftMask,            Button4, kscrollup,      {.i = 1} },
+	{ ShiftMask,            Button5, kscrolldown,    {.i = 1} },
 	{ 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"} },
 };
 
@@ -188,6 +203,8 @@ static Shortcut shortcuts[] = {
 	{ TERMMOD,              XK_Y,           selpaste,       {.i =  0} },
 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
 	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
+	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.f = -0.1} },
+	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.f = -0.1} },
 };
 
 /*

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$(X11LIB) -lm -lX11 -lutil -lXft \
-#       `pkg-config --libs fontconfig` \
-#       `pkg-config --libs freetype2`
+#       `$(PKG_CONFIG) --libs fontconfig` \
+#       `$(PKG_CONFIG) --libs freetype2`
+#MANPREFIX = ${PREFIX}/man
 
 # compiler and linker
 # CC = c99

patches/st-scrollback-float-0.9.2.diff

@@ -0,0 +1,52 @@
+diff --git a/config.def.h b/config.def.h
+index 8b25d40..6769f99 100644
+--- a/config.def.h
++++ b/config.def.h
+@@ -201,8 +201,8 @@ static Shortcut shortcuts[] = {
+ 	{ TERMMOD,              XK_Y,           selpaste,       {.i =  0} },
+ 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
+ 	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
+-	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.i = -1} },
+-	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.i = -1} },
++	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.f = -0.1} },
++	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.f = -0.1} },
+ };
+ 
+ /*
+diff --git a/st.c b/st.c
+index a3b3c9d..5a93594 100644
+--- a/st.c
++++ b/st.c
+@@ -1087,14 +1087,14 @@ tswapscreen(void)
+ void
+ kscrollup(const Arg *a)
+ {
+-	int n = a->i;
++	float n = a->f;
+ 
+ 	if (IS_SET(MODE_ALTSCREEN))
+ 		return;
+ 
+-	if (n < 0) n = (-n) * term.row;
++	if (n < 0) n = MAX((-n) * term.row, 1);
+ 	if (n > TSCREEN.size - term.row - TSCREEN.off) n = TSCREEN.size - term.row - TSCREEN.off;
+-	while (!TLINE(-n)) --n;
++	while (!TLINE((int)-n)) --n;
+ 	TSCREEN.off += n;
+ 	selscroll(0, n);
+ 	tfulldirt();
+@@ -1104,12 +1104,12 @@ void
+ kscrolldown(const Arg *a)
+ {
+ 
+-	int n = a->i;
++	float n = a->f;
+ 
+ 	if (IS_SET(MODE_ALTSCREEN))
+ 		return;
+ 
+-	if (n < 0) n = (-n) * term.row;
++	if (n < 0) n = MAX((-n) * term.row, 1);
+ 	if (n > TSCREEN.off) n = TSCREEN.off;
+ 	TSCREEN.off -= n;
+ 	selscroll(0, -n);

patches/st-scrollback-mouse-0.9.2.diff

@@ -0,0 +1,25 @@
+From 6b7e7e6c5c44dd6347ad49691b80d808c1b0cb77 Mon Sep 17 00:00:00 2001
+From: Jernej Jakob <jernej.jakob@gmail.com>
+Date: Mon, 1 Jul 2024 14:00:02 +0200
+Subject: [PATCH] [st][patch] Update st-scrollback-mouse for 0.9.2
+
+---
+ config.def.h | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/config.def.h b/config.def.h
+index 8b25d40..d259675 100644
+--- a/config.def.h
++++ b/config.def.h
+@@ -176,6 +176,8 @@ static uint forcemousemod = ShiftMask;
+  */
+ static MouseShortcut mshortcuts[] = {
+ 	/* mask                 button   function        argument       release */
++	{ ShiftMask,            Button4, kscrollup,      {.i = 1} },
++	{ ShiftMask,            Button5, kscrolldown,    {.i = 1} },
+ 	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},      1 },
+ 	{ ShiftMask,            Button4, ttysend,        {.s = "\033[5;2~"} },
+ 	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },
+-- 
+2.44.2
+

patches/st-scrollback-ringbuffer-0.9.2.diff

@@ -0,0 +1,730 @@
+commit 0663bdf11a409961da5b1120741a69814da8ce65
+Author: Timo Röhling <timo@gaussglocke.de>
+Date:   Tue Nov 23 19:45:33 2021 +0100
+
+    Terminal scrollback with ring buffer
+    
+    This patch adds a ring buffer for scrollback to the terminal.  The
+    advantage of using a ring buffer is that the common case, scrolling with
+    no static screen content, can be achieved very efficiently by
+    incrementing and decrementing the starting line (modulo buffer size).
+    
+    The scrollback buffer is limited to HISTSIZE lines in order to bound
+    memory usage. As the lines are allocated on demand, it is possible to
+    implement unlimited scrollback with few changes.  If the terminal is
+    reset, the scroll back buffer is reset, too.
+
+diff --git a/config.def.h b/config.def.h
+index 2cd740a..8b25d40 100644
+--- a/config.def.h
++++ b/config.def.h
+@@ -201,6 +201,8 @@ static Shortcut shortcuts[] = {
+ 	{ TERMMOD,              XK_Y,           selpaste,       {.i =  0} },
+ 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
+ 	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
++	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.i = -1} },
++	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.i = -1} },
+ };
+ 
+ /*
+diff --git a/st.c b/st.c
+index b9f66e7..d9b163e 100644
+--- a/st.c
++++ b/st.c
+@@ -43,6 +43,10 @@
+ #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
+ #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
+ 
++#define TSCREEN term.screen[IS_SET(MODE_ALTSCREEN)]
++#define TLINEOFFSET(y) (((y) + TSCREEN.cur - TSCREEN.off + TSCREEN.size) % TSCREEN.size)
++#define TLINE(y) (TSCREEN.buffer[TLINEOFFSET(y)])
++
+ enum term_mode {
+ 	MODE_WRAP        = 1 << 0,
+ 	MODE_INSERT      = 1 << 1,
+@@ -109,12 +113,21 @@ typedef struct {
+ 	int alt;
+ } Selection;
+ 
++/* Screen lines */
++typedef struct {
++	Line* buffer;  /* ring buffer */
++	int size;      /* size of buffer */
++	int cur;       /* start of active screen */
++	int off;       /* scrollback line offset */
++	TCursor sc;    /* saved cursor */
++} LineBuffer;
++
+ /* Internal representation of the screen */
+ typedef struct {
+ 	int row;      /* nb row */
+ 	int col;      /* nb col */
+-	Line *line;   /* screen */
+-	Line *alt;    /* alternate screen */
++	LineBuffer screen[2]; /* screen and alternate screen */
++	int linelen;  /* allocated line length */
+ 	int *dirty;   /* dirtyness of lines */
+ 	TCursor c;    /* cursor */
+ 	int ocx;      /* old cursor col */
+@@ -203,6 +216,8 @@ static void tdeftran(char);
+ static void tstrsequence(uchar);
+ 
+ static void drawregion(int, int, int, int);
++static void clearline(Line, Glyph, int, int);
++static Line ensureline(Line);
+ 
+ static void selnormalize(void);
+ static void selscroll(int, int);
+@@ -408,11 +423,12 @@ int
+ tlinelen(int y)
+ {
+ 	int i = term.col;
++	Line line = TLINE(y);
+ 
+-	if (term.line[y][i - 1].mode & ATTR_WRAP)
++	if (line[i - 1].mode & ATTR_WRAP)
+ 		return i;
+ 
+-	while (i > 0 && term.line[y][i - 1].u == ' ')
++	while (i > 0 && line[i - 1].u == ' ')
+ 		--i;
+ 
+ 	return i;
+@@ -521,7 +537,7 @@ selsnap(int *x, int *y, int direction)
+ 		 * Snap around if the word wraps around at the end or
+ 		 * beginning of a line.
+ 		 */
+-		prevgp = &term.line[*y][*x];
++		prevgp = &TLINE(*y)[*x];
+ 		prevdelim = ISDELIM(prevgp->u);
+ 		for (;;) {
+ 			newx = *x + direction;
+@@ -536,14 +552,14 @@ selsnap(int *x, int *y, int direction)
+ 					yt = *y, xt = *x;
+ 				else
+ 					yt = newy, xt = newx;
+-				if (!(term.line[yt][xt].mode & ATTR_WRAP))
++				if (!(TLINE(yt)[xt].mode & ATTR_WRAP))
+ 					break;
+ 			}
+ 
+ 			if (newx >= tlinelen(newy))
+ 				break;
+ 
+-			gp = &term.line[newy][newx];
++			gp = &TLINE(newy)[newx];
+ 			delim = ISDELIM(gp->u);
+ 			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
+ 					|| (delim && gp->u != prevgp->u)))
+@@ -564,14 +580,14 @@ selsnap(int *x, int *y, int direction)
+ 		*x = (direction < 0) ? 0 : term.col - 1;
+ 		if (direction < 0) {
+ 			for (; *y > 0; *y += direction) {
+-				if (!(term.line[*y-1][term.col-1].mode
++				if (!(TLINE(*y-1)[term.col-1].mode
+ 						& ATTR_WRAP)) {
+ 					break;
+ 				}
+ 			}
+ 		} else if (direction > 0) {
+ 			for (; *y < term.row-1; *y += direction) {
+-				if (!(term.line[*y][term.col-1].mode
++				if (!(TLINE(*y)[term.col-1].mode
+ 						& ATTR_WRAP)) {
+ 					break;
+ 				}
+@@ -602,13 +618,13 @@ getsel(void)
+ 		}
+ 
+ 		if (sel.type == SEL_RECTANGULAR) {
+-			gp = &term.line[y][sel.nb.x];
++			gp = &TLINE(y)[sel.nb.x];
+ 			lastx = sel.ne.x;
+ 		} else {
+-			gp = &term.line[y][sel.nb.y == y ? sel.nb.x : 0];
++			gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
+ 			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
+ 		}
+-		last = &term.line[y][MIN(lastx, linelen-1)];
++		last = &TLINE(y)[MIN(lastx, linelen-1)];
+ 		while (last >= gp && last->u == ' ')
+ 			--last;
+ 
+@@ -949,12 +965,15 @@ int
+ tattrset(int attr)
+ {
+ 	int i, j;
++	int y = TLINEOFFSET(0);
+ 
+ 	for (i = 0; i < term.row-1; i++) {
++		Line line = TSCREEN.buffer[y];
+ 		for (j = 0; j < term.col-1; j++) {
+-			if (term.line[i][j].mode & attr)
++			if (line[j].mode & attr)
+ 				return 1;
+ 		}
++		y = (y+1) % TSCREEN.size;
+ 	}
+ 
+ 	return 0;
+@@ -976,14 +995,17 @@ void
+ tsetdirtattr(int attr)
+ {
+ 	int i, j;
++	int y = TLINEOFFSET(0);
+ 
+ 	for (i = 0; i < term.row-1; i++) {
++		Line line = TSCREEN.buffer[y];
+ 		for (j = 0; j < term.col-1; j++) {
+-			if (term.line[i][j].mode & attr) {
++			if (line[j].mode & attr) {
+ 				tsetdirt(i, i);
+ 				break;
+ 			}
+ 		}
++		y = (y+1) % TSCREEN.size;
+ 	}
+ }
+ 
+@@ -996,27 +1018,19 @@ tfulldirt(void)
+ void
+ tcursor(int mode)
+ {
+-	static TCursor c[2];
+-	int alt = IS_SET(MODE_ALTSCREEN);
+-
+ 	if (mode == CURSOR_SAVE) {
+-		c[alt] = term.c;
++		TSCREEN.sc = term.c;
+ 	} else if (mode == CURSOR_LOAD) {
+-		term.c = c[alt];
+-		tmoveto(c[alt].x, c[alt].y);
++		term.c = TSCREEN.sc;
++		tmoveto(term.c.x, term.c.y);
+ 	}
+ }
+ 
+ void
+ treset(void)
+ {
+-	uint i;
+-
+-	term.c = (TCursor){{
+-		.mode = ATTR_NULL,
+-		.fg = defaultfg,
+-		.bg = defaultbg
+-	}, .x = 0, .y = 0, .state = CURSOR_DEFAULT};
++	int i, j;
++	Glyph g = (Glyph){ .fg = defaultfg, .bg = defaultbg};
+ 
+ 	memset(term.tabs, 0, term.col * sizeof(*term.tabs));
+ 	for (i = tabspaces; i < term.col; i += tabspaces)
+@@ -1028,17 +1042,37 @@ treset(void)
+ 	term.charset = 0;
+ 
+ 	for (i = 0; i < 2; i++) {
+-		tmoveto(0, 0);
+-		tcursor(CURSOR_SAVE);
+-		tclearregion(0, 0, term.col-1, term.row-1);
+-		tswapscreen();
++		term.screen[i].sc = (TCursor){{
++			.fg = defaultfg,
++			.bg = defaultbg
++		}};
++		term.screen[i].cur = 0;
++		term.screen[i].off = 0;
++		for (j = 0; j < term.row; ++j) {
++			if (term.col != term.linelen)
++				term.screen[i].buffer[j] = xrealloc(term.screen[i].buffer[j], term.col * sizeof(Glyph));
++			clearline(term.screen[i].buffer[j], g, 0, term.col);
++		}
++		for (j = term.row; j < term.screen[i].size; ++j) {
++			free(term.screen[i].buffer[j]);
++			term.screen[i].buffer[j] = NULL;
++		}
+ 	}
++	tcursor(CURSOR_LOAD);
++	term.linelen = term.col;
++	tfulldirt();
+ }
+ 
+ void
+ tnew(int col, int row)
+ {
+-	term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
++	int i;
++	term = (Term){};
++	term.screen[0].buffer = xmalloc(HISTSIZE * sizeof(Line));
++	term.screen[0].size = HISTSIZE;
++	term.screen[1].buffer = NULL;
++	for (i = 0; i < HISTSIZE; ++i) term.screen[0].buffer[i] = NULL;
++
+ 	tresize(col, row);
+ 	treset();
+ }
+@@ -1046,14 +1080,42 @@ tnew(int col, int row)
+ void
+ tswapscreen(void)
+ {
+-	Line *tmp = term.line;
+-
+-	term.line = term.alt;
+-	term.alt = tmp;
+ 	term.mode ^= MODE_ALTSCREEN;
+ 	tfulldirt();
+ }
+ 
++void
++kscrollup(const Arg *a)
++{
++	int n = a->i;
++
++	if (IS_SET(MODE_ALTSCREEN))
++		return;
++
++	if (n < 0) n = (-n) * term.row;
++	if (n > TSCREEN.size - term.row - TSCREEN.off) n = TSCREEN.size - term.row - TSCREEN.off;
++	while (!TLINE(-n)) --n;
++	TSCREEN.off += n;
++	selscroll(0, n);
++	tfulldirt();
++}
++
++void
++kscrolldown(const Arg *a)
++{
++
++	int n = a->i;
++
++	if (IS_SET(MODE_ALTSCREEN))
++		return;
++
++	if (n < 0) n = (-n) * term.row;
++	if (n > TSCREEN.off) n = TSCREEN.off;
++	TSCREEN.off -= n;
++	selscroll(0, -n);
++	tfulldirt();
++}
++
+ void
+ tscrolldown(int orig, int n)
+ {
+@@ -1062,15 +1124,29 @@ tscrolldown(int orig, int n)
+ 
+ 	LIMIT(n, 0, term.bot-orig+1);
+ 
+-	tsetdirt(orig, term.bot-n);
+-	tclearregion(0, term.bot-n+1, term.col-1, term.bot);
++	/* Ensure that lines are allocated */
++	for (i = -n; i < 0; i++) {
++		TLINE(i) = ensureline(TLINE(i));
++	}
+ 
+-	for (i = term.bot; i >= orig+n; i--) {
+-		temp = term.line[i];
+-		term.line[i] = term.line[i-n];
+-		term.line[i-n] = temp;
++	/* Shift non-scrolling areas in ring buffer */
++	for (i = term.bot+1; i < term.row; i++) {
++		temp = TLINE(i);
++		TLINE(i) = TLINE(i-n);
++		TLINE(i-n) = temp;
++	}
++	for (i = 0; i < orig; i++) {
++		temp = TLINE(i);
++		TLINE(i) = TLINE(i-n);
++		TLINE(i-n) = temp;
+ 	}
+ 
++	/* Scroll buffer */
++	TSCREEN.cur = (TSCREEN.cur + TSCREEN.size - n) % TSCREEN.size;
++	/* Clear lines that have entered the view */
++	tclearregion(0, orig, term.linelen-1, orig+n-1);
++	/* Redraw portion of the screen that has scrolled */
++	tsetdirt(orig+n-1, term.bot);
+ 	selscroll(orig, n);
+ }
+ 
+@@ -1082,15 +1158,29 @@ tscrollup(int orig, int n)
+ 
+ 	LIMIT(n, 0, term.bot-orig+1);
+ 
+-	tclearregion(0, orig, term.col-1, orig+n-1);
+-	tsetdirt(orig+n, term.bot);
++	/* Ensure that lines are allocated */
++	for (i = term.row; i < term.row + n; i++) {
++		TLINE(i) = ensureline(TLINE(i));
++	}
+ 
+-	for (i = orig; i <= term.bot-n; i++) {
+-		temp = term.line[i];
+-		term.line[i] = term.line[i+n];
+-		term.line[i+n] = temp;
++	/* Shift non-scrolling areas in ring buffer */
++	for (i = orig-1; i >= 0; i--) {
++		temp = TLINE(i);
++		TLINE(i) = TLINE(i+n);
++		TLINE(i+n) = temp;
++	}
++	for (i = term.row-1; i >term.bot; i--) {
++		temp = TLINE(i);
++		TLINE(i) = TLINE(i+n);
++		TLINE(i+n) = temp;
+ 	}
+ 
++	/* Scroll buffer */
++	TSCREEN.cur = (TSCREEN.cur + n) % TSCREEN.size;
++	/* Clear lines that have entered the view */
++	tclearregion(0, term.bot-n+1, term.linelen-1, term.bot);
++	/* Redraw portion of the screen that has scrolled */
++	tsetdirt(orig, term.bot-n+1);
+ 	selscroll(orig, -n);
+ }
+ 
+@@ -1194,6 +1284,7 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
+ 		"⎻", "─", "⎼", "⎽", "├", "┤", "┴", "┬", /* p - w */
+ 		"│", "≤", "≥", "π", "≠", "£", "·", /* x - ~ */
+ 	};
++	Line line = TLINE(y);
+ 
+ 	/*
+ 	 * The table is proudly stolen from rxvt.
+@@ -1202,25 +1293,25 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
+ 	   BETWEEN(u, 0x41, 0x7e) && vt100_0[u - 0x41])
+ 		utf8decode(vt100_0[u - 0x41], &u, UTF_SIZ);
+ 
+-	if (term.line[y][x].mode & ATTR_WIDE) {
++	if (line[x].mode & ATTR_WIDE) {
+ 		if (x+1 < term.col) {
+-			term.line[y][x+1].u = ' ';
+-			term.line[y][x+1].mode &= ~ATTR_WDUMMY;
++			line[x+1].u = ' ';
++			line[x+1].mode &= ~ATTR_WDUMMY;
+ 		}
+-	} else if (term.line[y][x].mode & ATTR_WDUMMY) {
+-		term.line[y][x-1].u = ' ';
+-		term.line[y][x-1].mode &= ~ATTR_WIDE;
++	} else if (line[x].mode & ATTR_WDUMMY) {
++		line[x-1].u = ' ';
++		line[x-1].mode &= ~ATTR_WIDE;
+ 	}
+ 
+ 	term.dirty[y] = 1;
+-	term.line[y][x] = *attr;
+-	term.line[y][x].u = u;
++	line[x] = *attr;
++	line[x].u = u;
+ }
+ 
+ void
+ tclearregion(int x1, int y1, int x2, int y2)
+ {
+-	int x, y, temp;
++	int x, y, L, S, temp;
+ 	Glyph *gp;
+ 
+ 	if (x1 > x2)
+@@ -1228,15 +1319,16 @@ tclearregion(int x1, int y1, int x2, int y2)
+ 	if (y1 > y2)
+ 		temp = y1, y1 = y2, y2 = temp;
+ 
+-	LIMIT(x1, 0, term.col-1);
+-	LIMIT(x2, 0, term.col-1);
++	LIMIT(x1, 0, term.linelen-1);
++	LIMIT(x2, 0, term.linelen-1);
+ 	LIMIT(y1, 0, term.row-1);
+ 	LIMIT(y2, 0, term.row-1);
+ 
++	L = TLINEOFFSET(y1);
+ 	for (y = y1; y <= y2; y++) {
+ 		term.dirty[y] = 1;
+ 		for (x = x1; x <= x2; x++) {
+-			gp = &term.line[y][x];
++			gp = &TSCREEN.buffer[L][x];
+ 			if (selected(x, y))
+ 				selclear();
+ 			gp->fg = term.c.attr.fg;
+@@ -1244,6 +1336,7 @@ tclearregion(int x1, int y1, int x2, int y2)
+ 			gp->mode = 0;
+ 			gp->u = ' ';
+ 		}
++		L = (L + 1) % TSCREEN.size;
+ 	}
+ }
+ 
+@@ -1258,7 +1351,7 @@ tdeletechar(int n)
+ 	dst = term.c.x;
+ 	src = term.c.x + n;
+ 	size = term.col - src;
+-	line = term.line[term.c.y];
++	line = TLINE(term.c.y);
+ 
+ 	memmove(&line[dst], &line[src], size * sizeof(Glyph));
+ 	tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
+@@ -1275,7 +1368,7 @@ tinsertblank(int n)
+ 	dst = term.c.x + n;
+ 	src = term.c.x;
+ 	size = term.col - dst;
+-	line = term.line[term.c.y];
++	line = TLINE(term.c.y);
+ 
+ 	memmove(&line[dst], &line[src], size * sizeof(Glyph));
+ 	tclearregion(src, term.c.y, dst - 1, term.c.y);
+@@ -2079,7 +2172,7 @@ tdumpline(int n)
+ 	char buf[UTF_SIZ];
+ 	const Glyph *bp, *end;
+ 
+-	bp = &term.line[n][0];
++	bp = &TLINE(n)[0];
+ 	end = &bp[MIN(tlinelen(n), term.col) - 1];
+ 	if (bp != end || bp->u != ' ') {
+ 		for ( ; bp <= end; ++bp)
+@@ -2466,11 +2559,11 @@ check_control_code:
+ 	if (selected(term.c.x, term.c.y))
+ 		selclear();
+ 
+-	gp = &term.line[term.c.y][term.c.x];
++	gp = &TLINE(term.c.y)[term.c.x];
+ 	if (IS_SET(MODE_WRAP) && (term.c.state & CURSOR_WRAPNEXT)) {
+ 		gp->mode |= ATTR_WRAP;
+ 		tnewline(1);
+-		gp = &term.line[term.c.y][term.c.x];
++		gp = &TLINE(term.c.y)[term.c.x];
+ 	}
+ 
+ 	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col) {
+@@ -2483,7 +2576,7 @@ check_control_code:
+ 			tnewline(1);
+ 		else
+ 			tmoveto(term.col - width, term.c.y);
+-		gp = &term.line[term.c.y][term.c.x];
++		gp = &TLINE(term.c.y)[term.c.x];
+ 	}
+ 
+ 	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
+@@ -2514,6 +2607,11 @@ twrite(const char *buf, int buflen, int show_ctrl)
+ 	Rune u;
+ 	int n;
+ 
++	if (TSCREEN.off) {
++		TSCREEN.off = 0;
++		tfulldirt();
++	}
++
+ 	for (n = 0; n < buflen; n += charsize) {
+ 		if (IS_SET(MODE_UTF8)) {
+ 			/* process a complete utf8 char */
+@@ -2540,56 +2638,85 @@ twrite(const char *buf, int buflen, int show_ctrl)
+ }
+ 
+ void
+-tresize(int col, int row)
++clearline(Line line, Glyph g, int x, int xend)
+ {
+ 	int i;
++	g.mode = 0;
++	g.u = ' ';
++	for (i = x; i < xend; ++i) {
++		line[i] = g;
++	}
++}
++
++Line
++ensureline(Line line)
++{
++	if (!line) {
++		line = xmalloc(term.linelen * sizeof(Glyph));
++	}
++	return line;
++}
++
++void
++tresize(int col, int row)
++{
++	int i, j;
+ 	int minrow = MIN(row, term.row);
+ 	int mincol = MIN(col, term.col);
++	int linelen = MAX(col, term.linelen);
+ 	int *bp;
+-	TCursor c;
+ 
+-	if (col < 1 || row < 1) {
++	if (col < 1 || row < 1 || row > HISTSIZE) {
+ 		fprintf(stderr,
+ 		        "tresize: error resizing to %dx%d\n", col, row);
+ 		return;
+ 	}
+ 
+-	/*
+-	 * slide screen to keep cursor where we expect it -
+-	 * tscrollup would work here, but we can optimize to
+-	 * memmove because we're freeing the earlier lines
+-	 */
+-	for (i = 0; i <= term.c.y - row; i++) {
+-		free(term.line[i]);
+-		free(term.alt[i]);
++	/* Shift buffer to keep the cursor where we expect it */
++	if (row <= term.c.y) {
++		term.screen[0].cur = (term.screen[0].cur - row + term.c.y + 1) % term.screen[0].size;
++	}
++
++	/* Resize and clear line buffers as needed */
++	if (linelen > term.linelen) {
++		for (i = 0; i < term.screen[0].size; ++i) {
++			if (term.screen[0].buffer[i]) {
++				term.screen[0].buffer[i] = xrealloc(term.screen[0].buffer[i], linelen * sizeof(Glyph));
++				clearline(term.screen[0].buffer[i], term.c.attr, term.linelen, linelen);
++			}
++		}
++		for (i = 0; i < minrow; ++i) {
++			term.screen[1].buffer[i] = xrealloc(term.screen[1].buffer[i], linelen * sizeof(Glyph));
++			clearline(term.screen[1].buffer[i], term.c.attr, term.linelen, linelen);
++		}
+ 	}
+-	/* ensure that both src and dst are not NULL */
+-	if (i > 0) {
+-		memmove(term.line, term.line + i, row * sizeof(Line));
+-		memmove(term.alt, term.alt + i, row * sizeof(Line));
++	/* Allocate all visible lines for regular line buffer */
++	for (j = term.screen[0].cur, i = 0; i < row; ++i, j = (j + 1) % term.screen[0].size)
++	{
++		if (!term.screen[0].buffer[j]) {
++			term.screen[0].buffer[j] = xmalloc(linelen * sizeof(Glyph));
++		}
++		if (i >= term.row) {
++			clearline(term.screen[0].buffer[j], term.c.attr, 0, linelen);
++		}
+ 	}
+-	for (i += row; i < term.row; i++) {
+-		free(term.line[i]);
+-		free(term.alt[i]);
++	/* Resize alt screen */
++	term.screen[1].cur = 0;
++	term.screen[1].size = row;
++	for (i = row; i < term.row; ++i) {
++		free(term.screen[1].buffer[i]);
++	}
++	term.screen[1].buffer = xrealloc(term.screen[1].buffer, row * sizeof(Line));
++	for (i = term.row; i < row; ++i) {
++		term.screen[1].buffer[i] = xmalloc(linelen * sizeof(Glyph));
++		clearline(term.screen[1].buffer[i], term.c.attr, 0, linelen);
+ 	}
+ 
+ 	/* resize to new height */
+-	term.line = xrealloc(term.line, row * sizeof(Line));
+-	term.alt  = xrealloc(term.alt,  row * sizeof(Line));
+ 	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
+ 	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
+ 
+-	/* resize each row to new width, zero-pad if needed */
+-	for (i = 0; i < minrow; i++) {
+-		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
+-		term.alt[i]  = xrealloc(term.alt[i],  col * sizeof(Glyph));
+-	}
+-
+-	/* allocate any new rows */
+-	for (/* i = minrow */; i < row; i++) {
+-		term.line[i] = xmalloc(col * sizeof(Glyph));
+-		term.alt[i] = xmalloc(col * sizeof(Glyph));
+-	}
++	/* fix tabstops */
+ 	if (col > term.col) {
+ 		bp = term.tabs + term.col;
+ 
+@@ -2599,26 +2726,16 @@ tresize(int col, int row)
+ 		for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
+ 			*bp = 1;
+ 	}
++
+ 	/* update terminal size */
+ 	term.col = col;
+ 	term.row = row;
++	term.linelen = linelen;
+ 	/* reset scrolling region */
+ 	tsetscroll(0, row-1);
+ 	/* make use of the LIMIT in tmoveto */
+ 	tmoveto(term.c.x, term.c.y);
+-	/* Clearing both screens (it makes dirty all lines) */
+-	c = term.c;
+-	for (i = 0; i < 2; i++) {
+-		if (mincol < col && 0 < minrow) {
+-			tclearregion(mincol, 0, col - 1, minrow - 1);
+-		}
+-		if (0 < col && minrow < row) {
+-			tclearregion(0, minrow, col - 1, row - 1);
+-		}
+-		tswapscreen();
+-		tcursor(CURSOR_LOAD);
+-	}
+-	term.c = c;
++	tfulldirt();
+ }
+ 
+ void
+@@ -2630,14 +2747,15 @@ resettitle(void)
+ void
+ drawregion(int x1, int y1, int x2, int y2)
+ {
+-	int y;
++	int y, L;
+ 
++	L = TLINEOFFSET(y1);
+ 	for (y = y1; y < y2; y++) {
+-		if (!term.dirty[y])
+-			continue;
+-
+-		term.dirty[y] = 0;
+-		xdrawline(term.line[y], x1, y, x2);
++		if (term.dirty[y]) {
++			term.dirty[y] = 0;
++			xdrawline(TSCREEN.buffer[L], x1, y, x2);
++		}
++		L = (L + 1) % TSCREEN.size;
+ 	}
+ }
+ 
+@@ -2652,14 +2770,15 @@ draw(void)
+ 	/* adjust cursor position */
+ 	LIMIT(term.ocx, 0, term.col-1);
+ 	LIMIT(term.ocy, 0, term.row-1);
+-	if (term.line[term.ocy][term.ocx].mode & ATTR_WDUMMY)
++	if (TLINE(term.ocy)[term.ocx].mode & ATTR_WDUMMY)
+ 		term.ocx--;
+-	if (term.line[term.c.y][cx].mode & ATTR_WDUMMY)
++	if (TLINE(term.c.y)[cx].mode & ATTR_WDUMMY)
+ 		cx--;
+ 
+ 	drawregion(0, 0, term.col, term.row);
+-	xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+-			term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
++	if (TSCREEN.off == 0)
++		xdrawcursor(cx, term.c.y, TLINE(term.c.y)[cx],
++				term.ocx, term.ocy, TLINE(term.ocy)[term.ocx]);
+ 	term.ocx = cx;
+ 	term.ocy = term.c.y;
+ 	xfinishdraw();
+diff --git a/st.h b/st.h
+index fd3b0d8..3cea73b 100644
+--- a/st.h
++++ b/st.h
+@@ -19,6 +19,7 @@
+ 
+ #define TRUECOLOR(r,g,b)	(1 << 24 | (r) << 16 | (g) << 8 | (b))
+ #define IS_TRUECOL(x)		(1 << 24 & (x))
++#define HISTSIZE            2000
+ 
+ enum glyph_attribute {
+ 	ATTR_NULL       = 0,
+diff --git a/x.c b/x.c
+index bd23686..25785a6 100644
+--- a/x.c
++++ b/x.c
+@@ -59,6 +59,8 @@ static void zoom(const Arg *);
+ static void zoomabs(const Arg *);
+ static void zoomreset(const Arg *);
+ static void ttysend(const Arg *);
++void kscrollup(const Arg *);
++void kscrolldown(const Arg *);
+ 
+ /* config.h for applying patches and the configuration. */
+ #include "config.h"

st.h

@@ -19,6 +19,7 @@
 
 #define TRUECOLOR(r,g,b)	(1 << 24 | (r) << 16 | (g) << 8 | (b))
 #define IS_TRUECOL(x)		(1 << 24 & (x))
+#define HISTSIZE            2000
 
 enum glyph_attribute {
 	ATTR_NULL       = 0,
@@ -91,7 +92,7 @@ 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 +110,7 @@ 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 +119,9 @@ 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 *);
@@ -59,6 +59,8 @@ static void zoom(const Arg *);
 static void zoomabs(const Arg *);
 static void zoomreset(const Arg *);
 static void ttysend(const Arg *);
+void kscrollup(const Arg *);
+void kscrolldown(const Arg *);
 
 /* config.h for applying patches and the configuration. */
 #include "config.h"
@@ -93,7 +95,7 @@ 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 +158,7 @@ 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 +254,7 @@ 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 +366,68 @@ mousesel(XEvent *e, int done)
 void
 mousereport(XEvent *e)
 {
-	int len, x = evcol(e), y = evrow(e),
-	    button = e->xbutton.button, state = e->xbutton.state;
+	int len, btn, code;
+	int x = evcol(e), y = evrow(e);
+	int state = e->xbutton.state;
 	char buf[40];
 	static int ox, oy;
 
-	/* from urxvt */
-	if (e->xbutton.type == MotionNotify) {
+	if (e->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 */
-		if (IS_SET(MODE_MOUSEMOTION) && oldbutton == 3)
+		/* MODE_MOUSEMOTION: no reporting if no button is pressed */
+		if (IS_SET(MODE_MOUSEMOTION) && buttons == 0)
 			return;
-
-		button = oldbutton + 32;
-		ox = x;
-		oy = y;
+		/* Set btn to lowest-numbered pressed button, or 12 if no
+		 * buttons are pressed. */
+		for (btn = 1; btn <= 11 && !(buttons & (1<<(btn-1))); btn++)
+			;
+		code = 32;
 	} else {
-		if (!IS_SET(MODE_MOUSESGR) && e->xbutton.type == ButtonRelease) {
-			button = 3;
-		} else {
-			button -= Button1;
-			if (button >= 3)
-				button += 64 - 3;
-		}
-		if (e->xbutton.type == ButtonPress) {
-			oldbutton = button;
-			ox = x;
-			oy = y;
-		} else if (e->xbutton.type == ButtonRelease) {
-			oldbutton = 3;
+		btn = e->xbutton.button;
+		/* Only buttons 1 through 11 can be encoded */
+		if (btn < 1 || btn > 11)
+			return;
+		if (e->type == ButtonRelease) {
 			/* 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)
-			+ ((state & Mod4Mask   ) ? 8  : 0)
-			+ ((state & ControlMask) ? 16 : 0);
+		code += ((state & ShiftMask  ) ?  4 : 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,
-				e->xbutton.type == ButtonRelease ? 'm' : 'M');
+				code, x+1, y+1,
+				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 +470,13 @@ 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 +485,7 @@ 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 +699,11 @@ 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 +711,7 @@ brelease(XEvent *e)
 
 	if (mouseaction(e, 1))
 		return;
-	if (e->xbutton.button == Button1)
+	if (btn == Button1)
 		mousesel(e, 1);
 }
 
@@ -797,12 +817,25 @@ 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 +983,7 @@ xloadfont(Font *f, FcPattern *pattern)
 }
 
 void
-xloadfonts(char *fontstr, double fontsize)
+xloadfonts(const char *fontstr, double fontsize)
 {
 	FcPattern *pattern;
 	double fontval;
@@ -958,7 +991,7 @@ 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 +1133,7 @@ xinit(int cols, int rows)
 {
 	XGCValues gcvalues;
 	Cursor cursor;
-	Window parent;
+	Window parent, root;
 	pid_t thispid = getpid();
 	XColor xmousefg, xmousebg;
 
@@ -1137,16 +1170,19 @@ 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);
-	xw.win = XCreateWindow(xw.dpy, parent, xw.l, xw.t,
+		parent = root;
+	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 +1222,7 @@ 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 +1498,12 @@ 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 +1563,9 @@ 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) */
-			g.u = 0x2603;
+		case 7: /* st extension */
+			g.u = 0x2603; /* snowman (U+2603) */
+			/* FALLTHROUGH */
 		case 0: /* Blinking Block */
 		case 1: /* Blinking Block (Default) */
 		case 2: /* Steady Block */
@@ -1578,14 +1616,35 @@ 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,
-			&prop);
+	if (p[0] == '\0')
+		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 +1748,7 @@ xsetmode(int set, unsigned int flags)
 int
 xsetcursor(int cursor)
 {
-	DEFAULT(cursor, 1);
-	if (!BETWEEN(cursor, 0, 6))
+	if (!BETWEEN(cursor, 0, 7)) /* 7: st extension */
 		return 1;
 	win.cursor = cursor;
 	return 0;
@@ -1786,7 +1844,7 @@ void
 kpress(XEvent *ev)
 {
 	XKeyEvent *e = &ev->xkey;
-	KeySym ksym;
+	KeySym ksym = NoSymbol;
 	char buf[64], *customkey;
 	int len;
 	Rune c;
@@ -1796,10 +1854,13 @@ 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 +1928,9 @@ 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 ttyfd;
-	struct timespec drawtimeout, *tv = NULL, now, last, lastblink;
-	long deltatime;
+	int xfd = XConnectionNumber(xw.dpy), ttyfd, xev, drawing;
+	struct timespec seltv, *tv, now, lastblink, trigger;
+	double timeout;
 
 	/* Waiting for window mapping */
 	do {
@@ -1891,82 +1951,77 @@ run(void)
 	ttyfd = ttynew(opt_line, shell, opt_io, opt_cmd);
 	cresize(w, h);
 
-	clock_gettime(CLOCK_MONOTONIC, &last);
-	lastblink = last;
-
-	for (xev = actionfps;;) {
+	for (timeout = -1, drawing = 0, lastblink = (struct timespec){0};;) {
 		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 (blinktimeout && TIMEDIFF(now, lastblink) > blinktimeout) {
-			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 (FD_ISSET(ttyfd, &rfd))
+			ttyread();
+
+		xev = 0;
+		while (XPending(xw.dpy)) {
+			xev = 1;
+			XNextEvent(xw.dpy, &ev);
+			if (XFilterEvent(&ev, None))
+				continue;
+			if (handler[ev.type])
+				(handler[ev.type])(&ev);
 		}
 
-		if (dodraw) {
-			while (XPending(xw.dpy)) {
-				XNextEvent(xw.dpy, &ev);
-				if (XFilterEvent(&ev, None))
-					continue;
-				if (handler[ev.type])
-					(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 */
+		}
 
-			draw();
-			XFlush(xw.dpy);
-
-			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;
-				}
+		/* 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;
 	}
 }
 
@@ -1988,7 +2043,7 @@ main(int argc, char *argv[])
 {
 	xw.l = xw.t = 0;
 	xw.isfixed = False;
-	win.cursor = cursorshape;
+	xsetcursor(cursorshape);
 
 	ARGBEGIN {
 	case 'a':