add ligatures

It is fixed in libXft 2.3.6:

https://gitlab.freedesktop.org/xorg/lib/libxft/-/blob/libXft-2.3.5/NEWS

.envrc

@@ -0,0 +1,2 @@
+use guix
+export CC="gcc -std=gnu99"

.gitignore

@@ -0,0 +1,2 @@
+*.o
+st

FAQ

@@ -248,3 +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

Makefile

@@ -4,7 +4,7 @@
 
 include config.mk
 
-SRC = st.c x.c
+SRC = st.c x.c hb.c
 OBJ = $(SRC:.c=.o)
 
 all: options st
@@ -22,7 +22,8 @@ config.h:
 	$(CC) $(STCFLAGS) -c $<
 
 st.o: config.h st.h win.h
-x.o: arg.h config.h st.h win.h
+x.o: arg.h config.h st.h win.h hb.h
+hb.o: st.h
 
 $(OBJ): config.h config.mk
 

config.h

@@ -0,0 +1,474 @@
+/* See LICENSE file for copyright and license details. */
+
+/*
+ * appearance
+ *
+ * font: see http://freedesktop.org/software/fontconfig/fontconfig-user.html
+ */
+static char *font = "Fira Code:pixelsize=16:antialias=true:autohint=true";
+static int borderpx = 2;
+
+/*
+ * What program is execed by st depends of these precedence rules:
+ * 1: program passed with -e
+ * 2: scroll and/or utmp
+ * 3: SHELL environment variable
+ * 4: value of shell in /etc/passwd
+ * 5: value of shell in config.h
+ */
+static char *shell = "/bin/sh";
+char *utmp = NULL;
+/* scroll program: to enable use a string like "scroll" */
+char *scroll = NULL;
+char *stty_args = "stty raw pass8 nl -echo -iexten -cstopb 38400";
+
+/* identification sequence returned in DA and DECID */
+char *vtiden = "\033[?6c";
+
+/* Kerning / character bounding-box multipliers */
+static float cwscale = 1.0;
+static float chscale = 1.0;
+
+/*
+ * word delimiter string
+ *
+ * More advanced example: L" `'\"()[]{}"
+ */
+wchar_t *worddelimiters = L" ";
+
+/* selection timeouts (in milliseconds) */
+static unsigned int doubleclicktimeout = 300;
+static unsigned int tripleclicktimeout = 600;
+
+/* alt screens */
+int allowaltscreen = 1;
+
+/* 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
+ * attribute.
+ */
+static unsigned int blinktimeout = 800;
+
+/*
+ * thickness of underline and bar cursors
+ */
+static unsigned int cursorthickness = 2;
+
+/*
+ * bell volume. It must be a value between -100 and 100. Use 0 for disabling
+ * it
+ */
+static int bellvolume = 0;
+
+/* default TERM value */
+char *termname = "st-256color";
+
+/*
+ * spaces per tab
+ *
+ * When you are changing this value, don't forget to adapt the »it« value in
+ * the st.info and appropriately install the st.info in the environment where
+ * you use this st version.
+ *
+ *	it#$tabspaces,
+ *
+ * Secondly make sure your kernel is not expanding tabs. When running `stty
+ * -a` »tab0« should appear. You can tell the terminal to not expand tabs by
+ *  running following command:
+ *
+ *	stty tabs
+ */
+unsigned int tabspaces = 8;
+
+/* Terminal colors (16 first used in escape sequence) */
+static const char *colorname[] = {
+	/* 8 normal colors */
+	"black",
+	"red3",
+	"green3",
+	"yellow3",
+	"blue2",
+	"magenta3",
+	"cyan3",
+	"gray90",
+
+	/* 8 bright colors */
+	"gray50",
+	"red",
+	"green",
+	"yellow",
+	"#5c5cff",
+	"magenta",
+	"cyan",
+	"white",
+
+	[255] = 0,
+
+	/* more colors can be added after 255 to use with DefaultXX */
+	"#cccccc",
+	"#555555",
+	"gray90", /* default foreground colour */
+	"black", /* default background colour */
+};
+
+
+/*
+ * Default colors (colorname index)
+ * foreground, background, cursor, reverse cursor
+ */
+unsigned int defaultfg = 258;
+unsigned int defaultbg = 259;
+unsigned int defaultcs = 256;
+static unsigned int defaultrcs = 257;
+
+/*
+ * Default shape of cursor
+ * 2: Block ("█")
+ * 4: Underline ("_")
+ * 6: Bar ("|")
+ * 7: Snowman ("☃")
+ */
+static unsigned int cursorshape = 2;
+
+/*
+ * Default columns and rows numbers
+ */
+
+static unsigned int cols = 80;
+static unsigned int rows = 24;
+
+/*
+ * Default colour and shape of the mouse cursor
+ */
+static unsigned int mouseshape = XC_xterm;
+static unsigned int mousefg = 7;
+static unsigned int mousebg = 0;
+
+/*
+ * Color used to display font attributes when fontconfig selected a font which
+ * doesn't match the ones requested.
+ */
+static unsigned int defaultattr = 11;
+
+/*
+ * Force mouse select/shortcuts while mask is active (when MODE_MOUSE is set).
+ * Note that if you want to use ShiftMask with selmasks, set this to an other
+ * modifier, set to 0 to not use it.
+ */
+static uint forcemousemod = ShiftMask;
+
+/*
+ * Internal mouse shortcuts.
+ * Beware that overloading Button1 will disable the selection.
+ */
+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"} },
+};
+
+/* Internal keyboard shortcuts. */
+#define MODKEY Mod1Mask
+#define TERMMOD (ControlMask|ShiftMask)
+
+static Shortcut shortcuts[] = {
+	/* mask                 keysym          function        argument */
+	{ XK_ANY_MOD,           XK_Break,       sendbreak,      {.i =  0} },
+	{ ControlMask,          XK_Print,       toggleprinter,  {.i =  0} },
+	{ ShiftMask,            XK_Print,       printscreen,    {.i =  0} },
+	{ XK_ANY_MOD,           XK_Print,       printsel,       {.i =  0} },
+	{ TERMMOD,              XK_Prior,       zoom,           {.f = +1} },
+	{ TERMMOD,              XK_Next,        zoom,           {.f = -1} },
+	{ TERMMOD,              XK_Home,        zoomreset,      {.f =  0} },
+	{ TERMMOD,              XK_C,           clipcopy,       {.i =  0} },
+	{ TERMMOD,              XK_V,           clippaste,      {.i =  0} },
+	{ TERMMOD,              XK_Y,           selpaste,       {.i =  0} },
+	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
+	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
+};
+
+/*
+ * Special keys (change & recompile st.info accordingly)
+ *
+ * Mask value:
+ * * Use XK_ANY_MOD to match the key no matter modifiers state
+ * * Use XK_NO_MOD to match the key alone (no modifiers)
+ * appkey value:
+ * * 0: no value
+ * * > 0: keypad application mode enabled
+ * *   = 2: term.numlock = 1
+ * * < 0: keypad application mode disabled
+ * appcursor value:
+ * * 0: no value
+ * * > 0: cursor application mode enabled
+ * * < 0: cursor application mode disabled
+ *
+ * Be careful with the order of the definitions because st searches in
+ * this table sequentially, so any XK_ANY_MOD must be in the last
+ * position for a key.
+ */
+
+/*
+ * If you want keys other than the X11 function keys (0xFD00 - 0xFFFF)
+ * to be mapped below, add them to this array.
+ */
+static KeySym mappedkeys[] = { -1 };
+
+/*
+ * State bits to ignore when matching key or button events.  By default,
+ * numlock (Mod2Mask) and keyboard layout (XK_SWITCH_MOD) are ignored.
+ */
+static uint ignoremod = Mod2Mask|XK_SWITCH_MOD;
+
+/*
+ * This is the huge key array which defines all compatibility to the Linux
+ * world. Please decide about changes wisely.
+ */
+static Key key[] = {
+	/* keysym           mask            string      appkey appcursor */
+	{ XK_KP_Home,       ShiftMask,      "\033[2J",       0,   -1},
+	{ XK_KP_Home,       ShiftMask,      "\033[1;2H",     0,   +1},
+	{ XK_KP_Home,       XK_ANY_MOD,     "\033[H",        0,   -1},
+	{ XK_KP_Home,       XK_ANY_MOD,     "\033[1~",       0,   +1},
+	{ XK_KP_Up,         XK_ANY_MOD,     "\033Ox",       +1,    0},
+	{ XK_KP_Up,         XK_ANY_MOD,     "\033[A",        0,   -1},
+	{ XK_KP_Up,         XK_ANY_MOD,     "\033OA",        0,   +1},
+	{ XK_KP_Down,       XK_ANY_MOD,     "\033Or",       +1,    0},
+	{ XK_KP_Down,       XK_ANY_MOD,     "\033[B",        0,   -1},
+	{ XK_KP_Down,       XK_ANY_MOD,     "\033OB",        0,   +1},
+	{ XK_KP_Left,       XK_ANY_MOD,     "\033Ot",       +1,    0},
+	{ XK_KP_Left,       XK_ANY_MOD,     "\033[D",        0,   -1},
+	{ XK_KP_Left,       XK_ANY_MOD,     "\033OD",        0,   +1},
+	{ XK_KP_Right,      XK_ANY_MOD,     "\033Ov",       +1,    0},
+	{ XK_KP_Right,      XK_ANY_MOD,     "\033[C",        0,   -1},
+	{ XK_KP_Right,      XK_ANY_MOD,     "\033OC",        0,   +1},
+	{ XK_KP_Prior,      ShiftMask,      "\033[5;2~",     0,    0},
+	{ XK_KP_Prior,      XK_ANY_MOD,     "\033[5~",       0,    0},
+	{ XK_KP_Begin,      XK_ANY_MOD,     "\033[E",        0,    0},
+	{ XK_KP_End,        ControlMask,    "\033[J",       -1,    0},
+	{ XK_KP_End,        ControlMask,    "\033[1;5F",    +1,    0},
+	{ XK_KP_End,        ShiftMask,      "\033[K",       -1,    0},
+	{ XK_KP_End,        ShiftMask,      "\033[1;2F",    +1,    0},
+	{ XK_KP_End,        XK_ANY_MOD,     "\033[4~",       0,    0},
+	{ XK_KP_Next,       ShiftMask,      "\033[6;2~",     0,    0},
+	{ XK_KP_Next,       XK_ANY_MOD,     "\033[6~",       0,    0},
+	{ XK_KP_Insert,     ShiftMask,      "\033[2;2~",    +1,    0},
+	{ XK_KP_Insert,     ShiftMask,      "\033[4l",      -1,    0},
+	{ XK_KP_Insert,     ControlMask,    "\033[L",       -1,    0},
+	{ XK_KP_Insert,     ControlMask,    "\033[2;5~",    +1,    0},
+	{ XK_KP_Insert,     XK_ANY_MOD,     "\033[4h",      -1,    0},
+	{ XK_KP_Insert,     XK_ANY_MOD,     "\033[2~",      +1,    0},
+	{ XK_KP_Delete,     ControlMask,    "\033[M",       -1,    0},
+	{ XK_KP_Delete,     ControlMask,    "\033[3;5~",    +1,    0},
+	{ XK_KP_Delete,     ShiftMask,      "\033[2K",      -1,    0},
+	{ XK_KP_Delete,     ShiftMask,      "\033[3;2~",    +1,    0},
+	{ XK_KP_Delete,     XK_ANY_MOD,     "\033[P",       -1,    0},
+	{ XK_KP_Delete,     XK_ANY_MOD,     "\033[3~",      +1,    0},
+	{ XK_KP_Multiply,   XK_ANY_MOD,     "\033Oj",       +2,    0},
+	{ XK_KP_Add,        XK_ANY_MOD,     "\033Ok",       +2,    0},
+	{ XK_KP_Enter,      XK_ANY_MOD,     "\033OM",       +2,    0},
+	{ XK_KP_Enter,      XK_ANY_MOD,     "\r",           -1,    0},
+	{ XK_KP_Subtract,   XK_ANY_MOD,     "\033Om",       +2,    0},
+	{ XK_KP_Decimal,    XK_ANY_MOD,     "\033On",       +2,    0},
+	{ XK_KP_Divide,     XK_ANY_MOD,     "\033Oo",       +2,    0},
+	{ XK_KP_0,          XK_ANY_MOD,     "\033Op",       +2,    0},
+	{ XK_KP_1,          XK_ANY_MOD,     "\033Oq",       +2,    0},
+	{ XK_KP_2,          XK_ANY_MOD,     "\033Or",       +2,    0},
+	{ XK_KP_3,          XK_ANY_MOD,     "\033Os",       +2,    0},
+	{ XK_KP_4,          XK_ANY_MOD,     "\033Ot",       +2,    0},
+	{ XK_KP_5,          XK_ANY_MOD,     "\033Ou",       +2,    0},
+	{ XK_KP_6,          XK_ANY_MOD,     "\033Ov",       +2,    0},
+	{ XK_KP_7,          XK_ANY_MOD,     "\033Ow",       +2,    0},
+	{ XK_KP_8,          XK_ANY_MOD,     "\033Ox",       +2,    0},
+	{ XK_KP_9,          XK_ANY_MOD,     "\033Oy",       +2,    0},
+	{ XK_Up,            ShiftMask,      "\033[1;2A",     0,    0},
+	{ XK_Up,            Mod1Mask,       "\033[1;3A",     0,    0},
+	{ XK_Up,         ShiftMask|Mod1Mask,"\033[1;4A",     0,    0},
+	{ XK_Up,            ControlMask,    "\033[1;5A",     0,    0},
+	{ XK_Up,      ShiftMask|ControlMask,"\033[1;6A",     0,    0},
+	{ XK_Up,       ControlMask|Mod1Mask,"\033[1;7A",     0,    0},
+	{ XK_Up,ShiftMask|ControlMask|Mod1Mask,"\033[1;8A",  0,    0},
+	{ XK_Up,            XK_ANY_MOD,     "\033[A",        0,   -1},
+	{ XK_Up,            XK_ANY_MOD,     "\033OA",        0,   +1},
+	{ XK_Down,          ShiftMask,      "\033[1;2B",     0,    0},
+	{ XK_Down,          Mod1Mask,       "\033[1;3B",     0,    0},
+	{ XK_Down,       ShiftMask|Mod1Mask,"\033[1;4B",     0,    0},
+	{ XK_Down,          ControlMask,    "\033[1;5B",     0,    0},
+	{ XK_Down,    ShiftMask|ControlMask,"\033[1;6B",     0,    0},
+	{ XK_Down,     ControlMask|Mod1Mask,"\033[1;7B",     0,    0},
+	{ XK_Down,ShiftMask|ControlMask|Mod1Mask,"\033[1;8B",0,    0},
+	{ XK_Down,          XK_ANY_MOD,     "\033[B",        0,   -1},
+	{ XK_Down,          XK_ANY_MOD,     "\033OB",        0,   +1},
+	{ XK_Left,          ShiftMask,      "\033[1;2D",     0,    0},
+	{ XK_Left,          Mod1Mask,       "\033[1;3D",     0,    0},
+	{ XK_Left,       ShiftMask|Mod1Mask,"\033[1;4D",     0,    0},
+	{ XK_Left,          ControlMask,    "\033[1;5D",     0,    0},
+	{ XK_Left,    ShiftMask|ControlMask,"\033[1;6D",     0,    0},
+	{ XK_Left,     ControlMask|Mod1Mask,"\033[1;7D",     0,    0},
+	{ XK_Left,ShiftMask|ControlMask|Mod1Mask,"\033[1;8D",0,    0},
+	{ XK_Left,          XK_ANY_MOD,     "\033[D",        0,   -1},
+	{ XK_Left,          XK_ANY_MOD,     "\033OD",        0,   +1},
+	{ XK_Right,         ShiftMask,      "\033[1;2C",     0,    0},
+	{ XK_Right,         Mod1Mask,       "\033[1;3C",     0,    0},
+	{ XK_Right,      ShiftMask|Mod1Mask,"\033[1;4C",     0,    0},
+	{ XK_Right,         ControlMask,    "\033[1;5C",     0,    0},
+	{ XK_Right,   ShiftMask|ControlMask,"\033[1;6C",     0,    0},
+	{ XK_Right,    ControlMask|Mod1Mask,"\033[1;7C",     0,    0},
+	{ XK_Right,ShiftMask|ControlMask|Mod1Mask,"\033[1;8C",0,   0},
+	{ XK_Right,         XK_ANY_MOD,     "\033[C",        0,   -1},
+	{ XK_Right,         XK_ANY_MOD,     "\033OC",        0,   +1},
+	{ XK_ISO_Left_Tab,  ShiftMask,      "\033[Z",        0,    0},
+	{ XK_Return,        Mod1Mask,       "\033\r",        0,    0},
+	{ XK_Return,        XK_ANY_MOD,     "\r",            0,    0},
+	{ XK_Insert,        ShiftMask,      "\033[4l",      -1,    0},
+	{ XK_Insert,        ShiftMask,      "\033[2;2~",    +1,    0},
+	{ XK_Insert,        ControlMask,    "\033[L",       -1,    0},
+	{ XK_Insert,        ControlMask,    "\033[2;5~",    +1,    0},
+	{ XK_Insert,        XK_ANY_MOD,     "\033[4h",      -1,    0},
+	{ XK_Insert,        XK_ANY_MOD,     "\033[2~",      +1,    0},
+	{ XK_Delete,        ControlMask,    "\033[M",       -1,    0},
+	{ XK_Delete,        ControlMask,    "\033[3;5~",    +1,    0},
+	{ XK_Delete,        ShiftMask,      "\033[2K",      -1,    0},
+	{ XK_Delete,        ShiftMask,      "\033[3;2~",    +1,    0},
+	{ XK_Delete,        XK_ANY_MOD,     "\033[P",       -1,    0},
+	{ XK_Delete,        XK_ANY_MOD,     "\033[3~",      +1,    0},
+	{ XK_BackSpace,     XK_NO_MOD,      "\177",          0,    0},
+	{ XK_BackSpace,     Mod1Mask,       "\033\177",      0,    0},
+	{ XK_Home,          ShiftMask,      "\033[2J",       0,   -1},
+	{ XK_Home,          ShiftMask,      "\033[1;2H",     0,   +1},
+	{ XK_Home,          XK_ANY_MOD,     "\033[H",        0,   -1},
+	{ XK_Home,          XK_ANY_MOD,     "\033[1~",       0,   +1},
+	{ XK_End,           ControlMask,    "\033[J",       -1,    0},
+	{ XK_End,           ControlMask,    "\033[1;5F",    +1,    0},
+	{ XK_End,           ShiftMask,      "\033[K",       -1,    0},
+	{ XK_End,           ShiftMask,      "\033[1;2F",    +1,    0},
+	{ XK_End,           XK_ANY_MOD,     "\033[4~",       0,    0},
+	{ XK_Prior,         ControlMask,    "\033[5;5~",     0,    0},
+	{ XK_Prior,         ShiftMask,      "\033[5;2~",     0,    0},
+	{ XK_Prior,         XK_ANY_MOD,     "\033[5~",       0,    0},
+	{ XK_Next,          ControlMask,    "\033[6;5~",     0,    0},
+	{ XK_Next,          ShiftMask,      "\033[6;2~",     0,    0},
+	{ XK_Next,          XK_ANY_MOD,     "\033[6~",       0,    0},
+	{ XK_F1,            XK_NO_MOD,      "\033OP" ,       0,    0},
+	{ XK_F1, /* F13 */  ShiftMask,      "\033[1;2P",     0,    0},
+	{ XK_F1, /* F25 */  ControlMask,    "\033[1;5P",     0,    0},
+	{ XK_F1, /* F37 */  Mod4Mask,       "\033[1;6P",     0,    0},
+	{ XK_F1, /* F49 */  Mod1Mask,       "\033[1;3P",     0,    0},
+	{ XK_F1, /* F61 */  Mod3Mask,       "\033[1;4P",     0,    0},
+	{ XK_F2,            XK_NO_MOD,      "\033OQ" ,       0,    0},
+	{ XK_F2, /* F14 */  ShiftMask,      "\033[1;2Q",     0,    0},
+	{ XK_F2, /* F26 */  ControlMask,    "\033[1;5Q",     0,    0},
+	{ XK_F2, /* F38 */  Mod4Mask,       "\033[1;6Q",     0,    0},
+	{ XK_F2, /* F50 */  Mod1Mask,       "\033[1;3Q",     0,    0},
+	{ XK_F2, /* F62 */  Mod3Mask,       "\033[1;4Q",     0,    0},
+	{ XK_F3,            XK_NO_MOD,      "\033OR" ,       0,    0},
+	{ XK_F3, /* F15 */  ShiftMask,      "\033[1;2R",     0,    0},
+	{ XK_F3, /* F27 */  ControlMask,    "\033[1;5R",     0,    0},
+	{ XK_F3, /* F39 */  Mod4Mask,       "\033[1;6R",     0,    0},
+	{ XK_F3, /* F51 */  Mod1Mask,       "\033[1;3R",     0,    0},
+	{ XK_F3, /* F63 */  Mod3Mask,       "\033[1;4R",     0,    0},
+	{ XK_F4,            XK_NO_MOD,      "\033OS" ,       0,    0},
+	{ XK_F4, /* F16 */  ShiftMask,      "\033[1;2S",     0,    0},
+	{ XK_F4, /* F28 */  ControlMask,    "\033[1;5S",     0,    0},
+	{ XK_F4, /* F40 */  Mod4Mask,       "\033[1;6S",     0,    0},
+	{ XK_F4, /* F52 */  Mod1Mask,       "\033[1;3S",     0,    0},
+	{ XK_F5,            XK_NO_MOD,      "\033[15~",      0,    0},
+	{ XK_F5, /* F17 */  ShiftMask,      "\033[15;2~",    0,    0},
+	{ XK_F5, /* F29 */  ControlMask,    "\033[15;5~",    0,    0},
+	{ XK_F5, /* F41 */  Mod4Mask,       "\033[15;6~",    0,    0},
+	{ XK_F5, /* F53 */  Mod1Mask,       "\033[15;3~",    0,    0},
+	{ XK_F6,            XK_NO_MOD,      "\033[17~",      0,    0},
+	{ XK_F6, /* F18 */  ShiftMask,      "\033[17;2~",    0,    0},
+	{ XK_F6, /* F30 */  ControlMask,    "\033[17;5~",    0,    0},
+	{ XK_F6, /* F42 */  Mod4Mask,       "\033[17;6~",    0,    0},
+	{ XK_F6, /* F54 */  Mod1Mask,       "\033[17;3~",    0,    0},
+	{ XK_F7,            XK_NO_MOD,      "\033[18~",      0,    0},
+	{ XK_F7, /* F19 */  ShiftMask,      "\033[18;2~",    0,    0},
+	{ XK_F7, /* F31 */  ControlMask,    "\033[18;5~",    0,    0},
+	{ XK_F7, /* F43 */  Mod4Mask,       "\033[18;6~",    0,    0},
+	{ XK_F7, /* F55 */  Mod1Mask,       "\033[18;3~",    0,    0},
+	{ XK_F8,            XK_NO_MOD,      "\033[19~",      0,    0},
+	{ XK_F8, /* F20 */  ShiftMask,      "\033[19;2~",    0,    0},
+	{ XK_F8, /* F32 */  ControlMask,    "\033[19;5~",    0,    0},
+	{ XK_F8, /* F44 */  Mod4Mask,       "\033[19;6~",    0,    0},
+	{ XK_F8, /* F56 */  Mod1Mask,       "\033[19;3~",    0,    0},
+	{ XK_F9,            XK_NO_MOD,      "\033[20~",      0,    0},
+	{ XK_F9, /* F21 */  ShiftMask,      "\033[20;2~",    0,    0},
+	{ XK_F9, /* F33 */  ControlMask,    "\033[20;5~",    0,    0},
+	{ XK_F9, /* F45 */  Mod4Mask,       "\033[20;6~",    0,    0},
+	{ XK_F9, /* F57 */  Mod1Mask,       "\033[20;3~",    0,    0},
+	{ XK_F10,           XK_NO_MOD,      "\033[21~",      0,    0},
+	{ XK_F10, /* F22 */ ShiftMask,      "\033[21;2~",    0,    0},
+	{ XK_F10, /* F34 */ ControlMask,    "\033[21;5~",    0,    0},
+	{ XK_F10, /* F46 */ Mod4Mask,       "\033[21;6~",    0,    0},
+	{ XK_F10, /* F58 */ Mod1Mask,       "\033[21;3~",    0,    0},
+	{ XK_F11,           XK_NO_MOD,      "\033[23~",      0,    0},
+	{ XK_F11, /* F23 */ ShiftMask,      "\033[23;2~",    0,    0},
+	{ XK_F11, /* F35 */ ControlMask,    "\033[23;5~",    0,    0},
+	{ XK_F11, /* F47 */ Mod4Mask,       "\033[23;6~",    0,    0},
+	{ XK_F11, /* F59 */ Mod1Mask,       "\033[23;3~",    0,    0},
+	{ XK_F12,           XK_NO_MOD,      "\033[24~",      0,    0},
+	{ XK_F12, /* F24 */ ShiftMask,      "\033[24;2~",    0,    0},
+	{ XK_F12, /* F36 */ ControlMask,    "\033[24;5~",    0,    0},
+	{ XK_F12, /* F48 */ Mod4Mask,       "\033[24;6~",    0,    0},
+	{ XK_F12, /* F60 */ Mod1Mask,       "\033[24;3~",    0,    0},
+	{ XK_F13,           XK_NO_MOD,      "\033[1;2P",     0,    0},
+	{ XK_F14,           XK_NO_MOD,      "\033[1;2Q",     0,    0},
+	{ XK_F15,           XK_NO_MOD,      "\033[1;2R",     0,    0},
+	{ XK_F16,           XK_NO_MOD,      "\033[1;2S",     0,    0},
+	{ XK_F17,           XK_NO_MOD,      "\033[15;2~",    0,    0},
+	{ XK_F18,           XK_NO_MOD,      "\033[17;2~",    0,    0},
+	{ XK_F19,           XK_NO_MOD,      "\033[18;2~",    0,    0},
+	{ XK_F20,           XK_NO_MOD,      "\033[19;2~",    0,    0},
+	{ XK_F21,           XK_NO_MOD,      "\033[20;2~",    0,    0},
+	{ XK_F22,           XK_NO_MOD,      "\033[21;2~",    0,    0},
+	{ XK_F23,           XK_NO_MOD,      "\033[23;2~",    0,    0},
+	{ XK_F24,           XK_NO_MOD,      "\033[24;2~",    0,    0},
+	{ XK_F25,           XK_NO_MOD,      "\033[1;5P",     0,    0},
+	{ XK_F26,           XK_NO_MOD,      "\033[1;5Q",     0,    0},
+	{ XK_F27,           XK_NO_MOD,      "\033[1;5R",     0,    0},
+	{ XK_F28,           XK_NO_MOD,      "\033[1;5S",     0,    0},
+	{ XK_F29,           XK_NO_MOD,      "\033[15;5~",    0,    0},
+	{ XK_F30,           XK_NO_MOD,      "\033[17;5~",    0,    0},
+	{ XK_F31,           XK_NO_MOD,      "\033[18;5~",    0,    0},
+	{ XK_F32,           XK_NO_MOD,      "\033[19;5~",    0,    0},
+	{ XK_F33,           XK_NO_MOD,      "\033[20;5~",    0,    0},
+	{ XK_F34,           XK_NO_MOD,      "\033[21;5~",    0,    0},
+	{ XK_F35,           XK_NO_MOD,      "\033[23;5~",    0,    0},
+};
+
+/*
+ * Selection types' masks.
+ * Use the same masks as usual.
+ * Button1Mask is always unset, to make masks match between ButtonPress.
+ * ButtonRelease and MotionNotify.
+ * If no match is found, regular selection is used.
+ */
+static uint selmasks[] = {
+	[SEL_RECTANGULAR] = Mod1Mask,
+};
+
+/*
+ * Printable characters in ASCII, used to estimate the advance width
+ * of single wide characters.
+ */
+static char ascii_printable[] =
+	" !\"#$%&'()*+,-./0123456789:;<=>?"
+	"@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_"
+	"`abcdefghijklmnopqrstuvwxyz{|}~";

config.mk

@@ -1,10 +1,10 @@
 # st version
-VERSION = 0.8.5
+VERSION = 0.9
 
 # Customize below to fit your system
 
 # paths
-PREFIX = /usr/local
+PREFIX = /home/pti/.local
 MANPREFIX = $(PREFIX)/share/man
 
 X11INC = /usr/X11R6/include
@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
 # includes and libs
 INCS = -I$(X11INC) \
        `$(PKG_CONFIG) --cflags fontconfig` \
-       `$(PKG_CONFIG) --cflags freetype2`
+       `$(PKG_CONFIG) --cflags freetype2` \
+       `$(PKG_CONFIG) --cflags harfbuzz`
 LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
        `$(PKG_CONFIG) --libs fontconfig` \
-       `$(PKG_CONFIG) --libs freetype2`
+       `$(PKG_CONFIG) --libs freetype2` \
+       `$(PKG_CONFIG) --libs harfbuzz`
 
 # flags
 STCPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600
@@ -30,6 +32,7 @@ STLDFLAGS = $(LIBS) $(LDFLAGS)
 #LIBS = -L$(X11LIB) -lm -lX11 -lutil -lXft \
 #       `$(PKG_CONFIG) --libs fontconfig` \
 #       `$(PKG_CONFIG) --libs freetype2`
+#MANPREFIX = ${PREFIX}/man
 
 # compiler and linker
 # CC = c99

hb.c

@@ -0,0 +1,125 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <X11/Xft/Xft.h>
+#include <X11/cursorfont.h>
+#include <hb.h>
+#include <hb-ft.h>
+
+#include "st.h"
+#include "hb.h"
+
+#define FEATURE(c1,c2,c3,c4) { .tag = HB_TAG(c1,c2,c3,c4), .value = 1, .start = HB_FEATURE_GLOBAL_START, .end = HB_FEATURE_GLOBAL_END }
+#define BUFFER_STEP 256
+
+hb_font_t *hbfindfont(XftFont *match);
+
+typedef struct {
+	XftFont *match;
+	hb_font_t *font;
+} HbFontMatch;
+
+typedef struct {
+	size_t capacity;
+	HbFontMatch *fonts;
+} HbFontCache;
+
+static HbFontCache hbfontcache = { 0, NULL };
+
+typedef struct {
+	size_t capacity;
+	Rune *runes;
+} RuneBuffer;
+
+static RuneBuffer hbrunebuffer = { 0, NULL };
+
+/*
+ * Poplulate the array with a list of font features, wrapped in FEATURE macro,
+ * e. g.
+ * FEATURE('c', 'a', 'l', 't'), FEATURE('d', 'l', 'i', 'g')
+ */
+hb_feature_t features[] = { };
+
+void
+hbunloadfonts()
+{
+	for (int i = 0; i < hbfontcache.capacity; i++) {
+		hb_font_destroy(hbfontcache.fonts[i].font);
+		XftUnlockFace(hbfontcache.fonts[i].match);
+	}
+
+	if (hbfontcache.fonts != NULL) {
+		free(hbfontcache.fonts);
+		hbfontcache.fonts = NULL;
+	}
+	hbfontcache.capacity = 0;
+}
+
+hb_font_t *
+hbfindfont(XftFont *match)
+{
+	for (int i = 0; i < hbfontcache.capacity; i++) {
+		if (hbfontcache.fonts[i].match == match)
+			return hbfontcache.fonts[i].font;
+	}
+
+	/* Font not found in cache, caching it now. */
+	hbfontcache.fonts = realloc(hbfontcache.fonts, sizeof(HbFontMatch) * (hbfontcache.capacity + 1));
+	FT_Face face = XftLockFace(match);
+	hb_font_t *font = hb_ft_font_create(face, NULL);
+	if (font == NULL)
+		die("Failed to load Harfbuzz font.");
+
+	hbfontcache.fonts[hbfontcache.capacity].match = match;
+	hbfontcache.fonts[hbfontcache.capacity].font = font;
+	hbfontcache.capacity += 1;
+
+	return font;
+}
+
+void hbtransform(HbTransformData *data, XftFont *xfont, const Glyph *glyphs, int start, int length) {
+	ushort mode = USHRT_MAX;
+	unsigned int glyph_count;
+	int rune_idx, glyph_idx, end = start + length;
+
+	hb_font_t *font = hbfindfont(xfont);
+	if (font == NULL)
+		return;
+
+	hb_buffer_t *buffer = hb_buffer_create();
+	hb_buffer_set_direction(buffer, HB_DIRECTION_LTR);
+	hb_buffer_set_cluster_level(buffer, HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS);
+
+	/* Resize the buffer if required length is larger. */
+	if (hbrunebuffer.capacity < length) {
+		hbrunebuffer.capacity = (length / BUFFER_STEP + 1) * BUFFER_STEP;
+		hbrunebuffer.runes = realloc(hbrunebuffer.runes, hbrunebuffer.capacity * sizeof(Rune));
+	}
+
+	/* Fill buffer with codepoints. */
+	for (rune_idx = 0, glyph_idx = start; glyph_idx < end; glyph_idx++, rune_idx++) {
+		hbrunebuffer.runes[rune_idx] = glyphs[glyph_idx].u;
+		mode = glyphs[glyph_idx].mode;
+		if (mode & ATTR_WDUMMY)
+			hbrunebuffer.runes[rune_idx] = 0x0020;
+	}
+	hb_buffer_add_codepoints(buffer, hbrunebuffer.runes, length, 0, length);
+
+	/* Shape the segment. */
+	hb_shape(font, buffer, features, sizeof(features)/sizeof(hb_feature_t));
+
+	/* Get new glyph info. */
+	hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, &glyph_count);
+	hb_glyph_position_t *pos = hb_buffer_get_glyph_positions(buffer, &glyph_count);
+
+	/* Fill the output. */
+	data->buffer = buffer;
+	data->glyphs = info;
+	data->positions = pos;
+	data->count = glyph_count;
+}
+
+void hbcleanup(HbTransformData *data) {
+	hb_buffer_destroy(data->buffer);
+	memset(data, 0, sizeof(HbTransformData));
+}

hb.h

@@ -0,0 +1,14 @@
+#include <X11/Xft/Xft.h>
+#include <hb.h>
+#include <hb-ft.h>
+
+typedef struct {
+	hb_buffer_t *buffer;
+	hb_glyph_info_t *glyphs;
+	hb_glyph_position_t *positions;
+	unsigned int count;
+} HbTransformData;
+
+void hbunloadfonts();
+void hbtransform(HbTransformData *, XftFont *, const Glyph *, int, int);
+void hbcleanup(HbTransformData *);

manifest.scm

@@ -0,0 +1,13 @@
+;; What follows is a "manifest" equivalent to the command line you gave.
+;; You can store it in a file that you may then pass to any 'guix' command
+;; that accepts a '--manifest' (or '-m') option.
+
+(specifications->manifest
+  (list "gcc-toolchain"
+        "pkg-config"
+        "patch"
+        "libx11"
+        "libxft"
+        "fontconfig"
+        "freetype"
+        "harfbuzz"))

st-ligatures-20240105-0.9.diff

@@ -0,0 +1,633 @@
+diff --git a/Makefile b/Makefile
+index 470ac86..38240da 100644
+--- a/Makefile
++++ b/Makefile
+@@ -4,7 +4,7 @@
+ 
+ include config.mk
+ 
+-SRC = st.c x.c
++SRC = st.c x.c hb.c
+ OBJ = $(SRC:.c=.o)
+ 
+ all: options st
+@@ -22,7 +22,8 @@ config.h:
+ 	$(CC) $(STCFLAGS) -c $<
+ 
+ st.o: config.h st.h win.h
+-x.o: arg.h config.h st.h win.h
++x.o: arg.h config.h st.h win.h hb.h
++hb.o: st.h
+ 
+ $(OBJ): config.h config.mk
+ 
+diff --git a/config.mk b/config.mk
+index 1e306f8..3e13e53 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(X11INC) \
+        `$(PKG_CONFIG) --cflags fontconfig` \
+-       `$(PKG_CONFIG) --cflags freetype2`
++       `$(PKG_CONFIG) --cflags freetype2` \
++       `$(PKG_CONFIG) --cflags harfbuzz`
+ LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
+        `$(PKG_CONFIG) --libs fontconfig` \
+-       `$(PKG_CONFIG) --libs freetype2`
++       `$(PKG_CONFIG) --libs freetype2` \
++       `$(PKG_CONFIG) --libs harfbuzz`
+ 
+ # flags
+ STCPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600
+diff --git a/hb.c b/hb.c
+new file mode 100644
+index 0000000..99412c8
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,125 @@
++#include <stdlib.h>
++#include <stdio.h>
++#include <math.h>
++#include <X11/Xft/Xft.h>
++#include <X11/cursorfont.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++#include "st.h"
++#include "hb.h"
++
++#define FEATURE(c1,c2,c3,c4) { .tag = HB_TAG(c1,c2,c3,c4), .value = 1, .start = HB_FEATURE_GLOBAL_START, .end = HB_FEATURE_GLOBAL_END }
++#define BUFFER_STEP 256
++
++hb_font_t *hbfindfont(XftFont *match);
++
++typedef struct {
++	XftFont *match;
++	hb_font_t *font;
++} HbFontMatch;
++
++typedef struct {
++	size_t capacity;
++	HbFontMatch *fonts;
++} HbFontCache;
++
++static HbFontCache hbfontcache = { 0, NULL };
++
++typedef struct {
++	size_t capacity;
++	Rune *runes;
++} RuneBuffer;
++
++static RuneBuffer hbrunebuffer = { 0, NULL };
++
++/*
++ * Poplulate the array with a list of font features, wrapped in FEATURE macro,
++ * e. g.
++ * FEATURE('c', 'a', 'l', 't'), FEATURE('d', 'l', 'i', 'g')
++ */
++hb_feature_t features[] = { };
++
++void
++hbunloadfonts()
++{
++	for (int i = 0; i < hbfontcache.capacity; i++) {
++		hb_font_destroy(hbfontcache.fonts[i].font);
++		XftUnlockFace(hbfontcache.fonts[i].match);
++	}
++
++	if (hbfontcache.fonts != NULL) {
++		free(hbfontcache.fonts);
++		hbfontcache.fonts = NULL;
++	}
++	hbfontcache.capacity = 0;
++}
++
++hb_font_t *
++hbfindfont(XftFont *match)
++{
++	for (int i = 0; i < hbfontcache.capacity; i++) {
++		if (hbfontcache.fonts[i].match == match)
++			return hbfontcache.fonts[i].font;
++	}
++
++	/* Font not found in cache, caching it now. */
++	hbfontcache.fonts = realloc(hbfontcache.fonts, sizeof(HbFontMatch) * (hbfontcache.capacity + 1));
++	FT_Face face = XftLockFace(match);
++	hb_font_t *font = hb_ft_font_create(face, NULL);
++	if (font == NULL)
++		die("Failed to load Harfbuzz font.");
++
++	hbfontcache.fonts[hbfontcache.capacity].match = match;
++	hbfontcache.fonts[hbfontcache.capacity].font = font;
++	hbfontcache.capacity += 1;
++
++	return font;
++}
++
++void hbtransform(HbTransformData *data, XftFont *xfont, const Glyph *glyphs, int start, int length) {
++	ushort mode = USHRT_MAX;
++	unsigned int glyph_count;
++	int rune_idx, glyph_idx, end = start + length;
++
++	hb_font_t *font = hbfindfont(xfont);
++	if (font == NULL)
++		return;
++
++	hb_buffer_t *buffer = hb_buffer_create();
++	hb_buffer_set_direction(buffer, HB_DIRECTION_LTR);
++	hb_buffer_set_cluster_level(buffer, HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS);
++
++	/* Resize the buffer if required length is larger. */
++	if (hbrunebuffer.capacity < length) {
++		hbrunebuffer.capacity = (length / BUFFER_STEP + 1) * BUFFER_STEP;
++		hbrunebuffer.runes = realloc(hbrunebuffer.runes, hbrunebuffer.capacity * sizeof(Rune));
++	}
++
++	/* Fill buffer with codepoints. */
++	for (rune_idx = 0, glyph_idx = start; glyph_idx < end; glyph_idx++, rune_idx++) {
++		hbrunebuffer.runes[rune_idx] = glyphs[glyph_idx].u;
++		mode = glyphs[glyph_idx].mode;
++		if (mode & ATTR_WDUMMY)
++			hbrunebuffer.runes[rune_idx] = 0x0020;
++	}
++	hb_buffer_add_codepoints(buffer, hbrunebuffer.runes, length, 0, length);
++
++	/* Shape the segment. */
++	hb_shape(font, buffer, features, sizeof(features)/sizeof(hb_feature_t));
++
++	/* Get new glyph info. */
++	hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, &glyph_count);
++	hb_glyph_position_t *pos = hb_buffer_get_glyph_positions(buffer, &glyph_count);
++
++	/* Fill the output. */
++	data->buffer = buffer;
++	data->glyphs = info;
++	data->positions = pos;
++	data->count = glyph_count;
++}
++
++void hbcleanup(HbTransformData *data) {
++	hb_buffer_destroy(data->buffer);
++	memset(data, 0, sizeof(HbTransformData));
++}
+diff --git a/hb.h b/hb.h
+new file mode 100644
+index 0000000..3b0ef44
+--- /dev/null
++++ b/hb.h
+@@ -0,0 +1,14 @@
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++typedef struct {
++	hb_buffer_t *buffer;
++	hb_glyph_info_t *glyphs;
++	hb_glyph_position_t *positions;
++	unsigned int count;
++} HbTransformData;
++
++void hbunloadfonts();
++void hbtransform(HbTransformData *, XftFont *, const Glyph *, int, int);
++void hbcleanup(HbTransformData *);
+diff --git a/st.c b/st.c
+index 62def59..041c6d8 100644
+--- a/st.c
++++ b/st.c
+@@ -2640,7 +2640,8 @@ draw(void)
+ 
+ 	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]);
++			term.ocx, term.ocy, term.line[term.ocy][term.ocx],
++			term.line[term.ocy], term.col);
+ 	term.ocx = cx;
+ 	term.ocy = term.c.y;
+ 	xfinishdraw();
+diff --git a/st.h b/st.h
+index fd3b0d8..142fdfe 100644
+--- a/st.h
++++ b/st.h
+@@ -11,7 +11,8 @@
+ #define DIVCEIL(n, d)		(((n) + ((d) - 1)) / (d))
+ #define DEFAULT(a, b)		(a) = (a) ? (a) : (b)
+ #define LIMIT(x, a, b)		(x) = (x) < (a) ? (a) : (x) > (b) ? (b) : (x)
+-#define ATTRCMP(a, b)		((a).mode != (b).mode || (a).fg != (b).fg || \
++#define ATTRCMP(a, b)		(((a).mode & (~ATTR_WRAP)) != ((b).mode & (~ATTR_WRAP)) || \
++				(a).fg != (b).fg || \
+ 				(a).bg != (b).bg)
+ #define TIMEDIFF(t1, t2)	((t1.tv_sec-t2.tv_sec)*1000 + \
+ 				(t1.tv_nsec-t2.tv_nsec)/1E6)
+diff --git a/win.h b/win.h
+index 6de960d..94679e4 100644
+--- a/win.h
++++ b/win.h
+@@ -25,7 +25,7 @@ enum win_mode {
+ 
+ void xbell(void);
+ void xclipcopy(void);
+-void xdrawcursor(int, int, Glyph, int, int, Glyph);
++void xdrawcursor(int, int, Glyph, int, int, Glyph, Line, int);
+ void xdrawline(Line, int, int, int);
+ void xfinishdraw(void);
+ void xloadcols(void);
+diff --git a/x.c b/x.c
+index 2a3bd38..66605ae 100644
+--- a/x.c
++++ b/x.c
+@@ -19,6 +19,7 @@ char *argv0;
+ #include "arg.h"
+ #include "st.h"
+ #include "win.h"
++#include "hb.h"
+ 
+ /* types used in config.h */
+ typedef struct {
+@@ -141,8 +142,9 @@ typedef struct {
+ } DC;
+ 
+ static inline ushort sixd_to_16bit(int);
++static void xresetfontsettings(ushort mode, Font **font, int *frcflags);
+ static int xmakeglyphfontspecs(XftGlyphFontSpec *, const Glyph *, int, int, int);
+-static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int);
++static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int, int);
+ static void xdrawglyph(Glyph, int, int);
+ static void xclear(int, int, int, int);
+ static int xgeommasktogravity(int);
+@@ -757,7 +759,7 @@ xresize(int col, int row)
+ 	xclear(0, 0, win.w, win.h);
+ 
+ 	/* resize to new width */
+-	xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec));
++	xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec) * 4);
+ }
+ 
+ ushort
+@@ -1062,6 +1064,9 @@ xunloadfont(Font *f)
+ void
+ xunloadfonts(void)
+ {
++	/* Clear Harfbuzz font cache. */
++	hbunloadfonts();
++
+ 	/* Free the loaded fonts in the font cache.  */
+ 	while (frclen > 0)
+ 		XftFontClose(xw.dpy, frc[--frclen].font);
+@@ -1185,7 +1190,7 @@ xinit(int cols, int rows)
+ 	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
+ 
+ 	/* font spec buffer */
+-	xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec));
++	xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec) * 4);
+ 
+ 	/* Xft rendering context */
+ 	xw.draw = XftDrawCreate(xw.dpy, xw.buf, xw.vis, xw.cmap);
+@@ -1239,6 +1244,22 @@ xinit(int cols, int rows)
+ 		xsel.xtarget = XA_STRING;
+ }
+ 
++void
++xresetfontsettings(ushort mode, Font **font, int *frcflags)
++{
++	*font = &dc.font;
++	if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD)) {
++		*font = &dc.ibfont;
++		*frcflags = FRC_ITALICBOLD;
++	} else if (mode & ATTR_ITALIC) {
++		*font = &dc.ifont;
++		*frcflags = FRC_ITALIC;
++	} else if (mode & ATTR_BOLD) {
++		*font = &dc.bfont;
++		*frcflags = FRC_BOLD;
++	}
++}
++
+ int
+ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x, int y)
+ {
+@@ -1253,128 +1274,156 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
+ 	FcPattern *fcpattern, *fontpattern;
+ 	FcFontSet *fcsets[] = { NULL };
+ 	FcCharSet *fccharset;
+-	int i, f, numspecs = 0;
++	int i, f, length = 0, start = 0, numspecs = 0;
++	float cluster_xp = xp, cluster_yp = yp;
++	HbTransformData shaped = { 0 };
++
++	/* Initial values. */
++	mode = prevmode = glyphs[0].mode & ~ATTR_WRAP;
++	xresetfontsettings(mode, &font, &frcflags);
+ 
+ 	for (i = 0, xp = winx, yp = winy + font->ascent; i < len; ++i) {
+-		/* Fetch rune and mode for current glyph. */
+-		rune = glyphs[i].u;
+-		mode = glyphs[i].mode;
++		mode = glyphs[i].mode & ~ATTR_WRAP;
+ 
+ 		/* Skip dummy wide-character spacing. */
+-		if (mode == ATTR_WDUMMY)
++		if (mode & ATTR_WDUMMY && i < (len - 1))
+ 			continue;
+ 
+-		/* Determine font for glyph if different from previous glyph. */
+-		if (prevmode != mode) {
+-			prevmode = mode;
+-			font = &dc.font;
+-			frcflags = FRC_NORMAL;
+-			runewidth = win.cw * ((mode & ATTR_WIDE) ? 2.0f : 1.0f);
+-			if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD)) {
+-				font = &dc.ibfont;
+-				frcflags = FRC_ITALICBOLD;
+-			} else if (mode & ATTR_ITALIC) {
+-				font = &dc.ifont;
+-				frcflags = FRC_ITALIC;
+-			} else if (mode & ATTR_BOLD) {
+-				font = &dc.bfont;
+-				frcflags = FRC_BOLD;
++		if (
++			prevmode != mode
++			|| ATTRCMP(glyphs[start], glyphs[i])
++			|| selected(x + i, y) != selected(x + start, y)
++			|| i == (len - 1)
++		) {
++			/* Handle 1-character wide segments and end of line */
++			length = i - start;
++			if (i == start) {
++				length = 1;
++			} else if (i == (len - 1)) {
++				length = (i - start + 1);
+ 			}
+-			yp = winy + font->ascent;
+-		}
+ 
+-		/* Lookup character index with default font. */
+-		glyphidx = XftCharIndex(xw.dpy, font->match, rune);
+-		if (glyphidx) {
+-			specs[numspecs].font = font->match;
+-			specs[numspecs].glyph = glyphidx;
+-			specs[numspecs].x = (short)xp;
+-			specs[numspecs].y = (short)yp;
+-			xp += runewidth;
+-			numspecs++;
+-			continue;
+-		}
+-
+-		/* Fallback on font cache, search the font cache for match. */
+-		for (f = 0; f < frclen; f++) {
+-			glyphidx = XftCharIndex(xw.dpy, frc[f].font, rune);
+-			/* Everything correct. */
+-			if (glyphidx && frc[f].flags == frcflags)
+-				break;
+-			/* We got a default font for a not found glyph. */
+-			if (!glyphidx && frc[f].flags == frcflags
+-					&& frc[f].unicodep == rune) {
+-				break;
++			/* Shape the segment. */
++			hbtransform(&shaped, font->match, glyphs, start, length);
++			runewidth = win.cw * ((glyphs[start].mode & ATTR_WIDE) ? 2.0f : 1.0f);
++			cluster_xp = xp; cluster_yp = yp;
++			for (int code_idx = 0; code_idx < shaped.count; code_idx++) {
++				int idx = shaped.glyphs[code_idx].cluster;
++
++				if (glyphs[start + idx].mode & ATTR_WDUMMY)
++					continue;
++
++				/* Advance the drawing cursor if we've moved to a new cluster */
++				if (code_idx > 0 && idx != shaped.glyphs[code_idx - 1].cluster) {
++					xp += runewidth;
++					cluster_xp = xp;
++					cluster_yp = yp;
++					runewidth = win.cw * ((glyphs[start + idx].mode & ATTR_WIDE) ? 2.0f : 1.0f);
++				}
++
++				if (shaped.glyphs[code_idx].codepoint != 0) {
++					/* If symbol is found, put it into the specs. */
++					specs[numspecs].font = font->match;
++					specs[numspecs].glyph = shaped.glyphs[code_idx].codepoint;
++					specs[numspecs].x = cluster_xp + (short)(shaped.positions[code_idx].x_offset / 64.);
++					specs[numspecs].y = cluster_yp - (short)(shaped.positions[code_idx].y_offset / 64.);
++					cluster_xp += shaped.positions[code_idx].x_advance / 64.;
++					cluster_yp += shaped.positions[code_idx].y_advance / 64.;
++					numspecs++;
++				} else {
++					/* If it's not found, try to fetch it through the font cache. */
++					rune = glyphs[start + idx].u;
++					for (f = 0; f < frclen; f++) {
++						glyphidx = XftCharIndex(xw.dpy, frc[f].font, rune);
++						/* Everything correct. */
++						if (glyphidx && frc[f].flags == frcflags)
++							break;
++						/* We got a default font for a not found glyph. */
++						if (!glyphidx && frc[f].flags == frcflags
++								&& frc[f].unicodep == rune) {
++							break;
++						}
++					}
++
++					/* Nothing was found. Use fontconfig to find matching font. */
++					if (f >= frclen) {
++						if (!font->set)
++							font->set = FcFontSort(0, font->pattern,
++																		 1, 0, &fcres);
++						fcsets[0] = font->set;
++
++						/*
++						 * Nothing was found in the cache. Now use
++						 * some dozen of Fontconfig calls to get the
++						 * font for one single character.
++						 *
++						 * Xft and fontconfig are design failures.
++						 */
++						fcpattern = FcPatternDuplicate(font->pattern);
++						fccharset = FcCharSetCreate();
++
++						FcCharSetAddChar(fccharset, rune);
++						FcPatternAddCharSet(fcpattern, FC_CHARSET,
++								fccharset);
++						FcPatternAddBool(fcpattern, FC_SCALABLE, 1);
++
++						FcConfigSubstitute(0, fcpattern,
++								FcMatchPattern);
++						FcDefaultSubstitute(fcpattern);
++
++						fontpattern = FcFontSetMatch(0, fcsets, 1,
++								fcpattern, &fcres);
++
++						/* Allocate memory for the new cache entry. */
++						if (frclen >= frccap) {
++							frccap += 16;
++							frc = xrealloc(frc, frccap * sizeof(Fontcache));
++						}
++
++						frc[frclen].font = XftFontOpenPattern(xw.dpy,
++								fontpattern);
++						if (!frc[frclen].font)
++							die("XftFontOpenPattern failed seeking fallback font: %s\n",
++								strerror(errno));
++						frc[frclen].flags = frcflags;
++						frc[frclen].unicodep = rune;
++
++						glyphidx = XftCharIndex(xw.dpy, frc[frclen].font, rune);
++
++						f = frclen;
++						frclen++;
++
++						FcPatternDestroy(fcpattern);
++						FcCharSetDestroy(fccharset);
++					}
++
++					specs[numspecs].font = frc[f].font;
++					specs[numspecs].glyph = glyphidx;
++					specs[numspecs].x = (short)xp;
++					specs[numspecs].y = (short)yp;
++					numspecs++;
++				}
+ 			}
+-		}
+ 
+-		/* Nothing was found. Use fontconfig to find matching font. */
+-		if (f >= frclen) {
+-			if (!font->set)
+-				font->set = FcFontSort(0, font->pattern,
+-				                       1, 0, &fcres);
+-			fcsets[0] = font->set;
++			/* Cleanup and get ready for next segment. */
++			hbcleanup(&shaped);
++			start = i;
+ 
+-			/*
+-			 * Nothing was found in the cache. Now use
+-			 * some dozen of Fontconfig calls to get the
+-			 * font for one single character.
+-			 *
+-			 * Xft and fontconfig are design failures.
+-			 */
+-			fcpattern = FcPatternDuplicate(font->pattern);
+-			fccharset = FcCharSetCreate();
+-
+-			FcCharSetAddChar(fccharset, rune);
+-			FcPatternAddCharSet(fcpattern, FC_CHARSET,
+-					fccharset);
+-			FcPatternAddBool(fcpattern, FC_SCALABLE, 1);
+-
+-			FcConfigSubstitute(0, fcpattern,
+-					FcMatchPattern);
+-			FcDefaultSubstitute(fcpattern);
+-
+-			fontpattern = FcFontSetMatch(0, fcsets, 1,
+-					fcpattern, &fcres);
+-
+-			/* Allocate memory for the new cache entry. */
+-			if (frclen >= frccap) {
+-				frccap += 16;
+-				frc = xrealloc(frc, frccap * sizeof(Fontcache));
++			/* Determine font for glyph if different from previous glyph. */
++			if (prevmode != mode) {
++				prevmode = mode;
++				xresetfontsettings(mode, &font, &frcflags);
++				yp = winy + font->ascent;
+ 			}
+-
+-			frc[frclen].font = XftFontOpenPattern(xw.dpy,
+-					fontpattern);
+-			if (!frc[frclen].font)
+-				die("XftFontOpenPattern failed seeking fallback font: %s\n",
+-					strerror(errno));
+-			frc[frclen].flags = frcflags;
+-			frc[frclen].unicodep = rune;
+-
+-			glyphidx = XftCharIndex(xw.dpy, frc[frclen].font, rune);
+-
+-			f = frclen;
+-			frclen++;
+-
+-			FcPatternDestroy(fcpattern);
+-			FcCharSetDestroy(fccharset);
+ 		}
+-
+-		specs[numspecs].font = frc[f].font;
+-		specs[numspecs].glyph = glyphidx;
+-		specs[numspecs].x = (short)xp;
+-		specs[numspecs].y = (short)yp;
+-		xp += runewidth;
+-		numspecs++;
+ 	}
+ 
+ 	return numspecs;
+ }
+ 
+ void
+-xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, int y)
++xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, int y, int charlen)
+ {
+-	int charlen = len * ((base.mode & ATTR_WIDE) ? 2 : 1);
+ 	int winx = borderpx + x * win.cw, winy = borderpx + y * win.ch,
+ 	    width = charlen * win.cw;
+ 	Color *fg, *bg, *temp, revfg, revbg, truefg, truebg;
+@@ -1510,21 +1559,24 @@ void
+ xdrawglyph(Glyph g, int x, int y)
+ {
+ 	int numspecs;
+-	XftGlyphFontSpec spec;
++	XftGlyphFontSpec *specs = xw.specbuf;
+ 
+-	numspecs = xmakeglyphfontspecs(&spec, &g, 1, x, y);
+-	xdrawglyphfontspecs(&spec, g, numspecs, x, y);
++	numspecs = xmakeglyphfontspecs(specs, &g, 1, x, y);
++	xdrawglyphfontspecs(specs, g, numspecs, x, y, (g.mode & ATTR_WIDE) ? 2 : 1);
+ }
+ 
+ void
+-xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
++xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og, Line line, int len)
+ {
+ 	Color drawcol;
+ 
+ 	/* remove the old cursor */
+ 	if (selected(ox, oy))
+ 		og.mode ^= ATTR_REVERSE;
+-	xdrawglyph(og, ox, oy);
++
++	/* Redraw the line where cursor was previously.
++	 * It will restore the ligatures broken by the cursor. */
++	xdrawline(line, 0, oy, len);
+ 
+ 	if (IS_SET(MODE_HIDE))
+ 		return;
+@@ -1652,18 +1704,16 @@ xdrawline(Line line, int x1, int y1, int x2)
+ 	Glyph base, new;
+ 	XftGlyphFontSpec *specs = xw.specbuf;
+ 
+-	numspecs = xmakeglyphfontspecs(specs, &line[x1], x2 - x1, x1, y1);
+ 	i = ox = 0;
+-	for (x = x1; x < x2 && i < numspecs; x++) {
++	for (x = x1; x < x2; x++) {
+ 		new = line[x];
+ 		if (new.mode == ATTR_WDUMMY)
+ 			continue;
+ 		if (selected(x, y1))
+ 			new.mode ^= ATTR_REVERSE;
+-		if (i > 0 && ATTRCMP(base, new)) {
+-			xdrawglyphfontspecs(specs, base, i, ox, y1);
+-			specs += i;
+-			numspecs -= i;
++		if ((i > 0) && ATTRCMP(base, new)) {
++			numspecs = xmakeglyphfontspecs(specs, &line[ox], x - ox, ox, y1);
++			xdrawglyphfontspecs(specs, base, numspecs, ox, y1, x - ox);
+ 			i = 0;
+ 		}
+ 		if (i == 0) {
+@@ -1672,8 +1722,10 @@ xdrawline(Line line, int x1, int y1, int x2)
+ 		}
+ 		i++;
+ 	}
+-	if (i > 0)
+-		xdrawglyphfontspecs(specs, base, i, ox, y1);
++	if (i > 0) {
++		numspecs = xmakeglyphfontspecs(specs, &line[ox], x2 - ox, ox, y1);
++		xdrawglyphfontspecs(specs, base, numspecs, ox, y1, x2 - ox);
++	}
+ }
+ 
+ void

st.c

@@ -161,6 +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);
@@ -349,25 +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 */
 }
@@ -377,6 +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);
@@ -946,7 +939,7 @@ ttyresize(int tw, int th)
 }
 
 void
-ttyhangup()
+ttyhangup(void)
 {
 	/* Send SIGHUP to shell */
 	kill(pid, SIGHUP);
@@ -1843,39 +1836,28 @@ csireset(void)
 }
 
 void
-osc4_color_response(int num)
+osc_color_response(int num, int index, int is_osc4)
 {
 	int n;
 	char buf[32];
 	unsigned char r, g, b;
 
-	if (xgetcolor(num, &r, &g, &b)) {
+	if (xgetcolor(is_osc4 ? num : index, &r, &g, &b)) {
-		fprintf(stderr, "erresc: failed to fetch osc4 color %d\n", num);
+		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]4;%d;rgb:%02x%02x/%02x%02x/%02x%02x\007",
+	n = snprintf(buf, sizeof buf, "\033]%s%d;rgb:%02x%02x/%02x%02x/%02x%02x\007",
-		     num, r, r, g, g, b, b);
+	             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
-osc_color_response(int index, int num)
-{
-	int n;
-	char buf[32];
-	unsigned char r, g, b;
-
-	if (xgetcolor(index, &r, &g, &b)) {
-		fprintf(stderr, "erresc: failed to fetch osc color %d\n", index);
-		return;
-	}
-
-	n = snprintf(buf, sizeof buf, "\033]%d;rgb:%02x%02x/%02x%02x/%02x%02x\007",
-		     num, r, r, g, g, b, b);
-
-	ttywrite(buf, n, 1);
 }
 
 void
@@ -1883,6 +1865,11 @@ 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();
@@ -1917,43 +1904,22 @@ strhandle(void)
 			}
 			return;
 		case 10:
-			if (narg < 2)
-				break;
-
-			p = strescseq.args[1];
-
-			if (!strcmp(p, "?"))
-				osc_color_response(defaultfg, 10);
-			else if (xsetcolorname(defaultfg, p))
-				fprintf(stderr, "erresc: invalid foreground color: %s\n", p);
-			else
-				redraw();
-			return;
 		case 11:
-			if (narg < 2)
-				break;
-
-			p = strescseq.args[1];
-
-			if (!strcmp(p, "?"))
-				osc_color_response(defaultbg, 11);
-			else if (xsetcolorname(defaultbg, p))
-				fprintf(stderr, "erresc: invalid background color: %s\n", p);
-			else
-				redraw();
-			return;
 		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, "?"))
+			if (!strcmp(p, "?")) {
-				osc_color_response(defaultcs, 12);
+				osc_color_response(par, osc_table[j].idx, 0);
-			else if (xsetcolorname(defaultcs, p))
+			} else if (xsetcolorname(osc_table[j].idx, p)) {
-				fprintf(stderr, "erresc: invalid cursor color: %s\n", p);
+				fprintf(stderr, "erresc: invalid %s color: %s\n",
-			else
+				        osc_table[j].str, p);
-				redraw();
+			} else {
+				tfulldirt();
+			}
 			return;
 		case 4: /* color set */
 			if (narg < 3)
@@ -1963,9 +1929,9 @@ strhandle(void)
 		case 104: /* color reset */
 			j = (narg > 1) ? atoi(strescseq.args[1]) : -1;
 
-			if (p && !strcmp(p, "?"))
+			if (p && !strcmp(p, "?")) {
-				osc4_color_response(j);
+				osc_color_response(j, 0, 1);
-			else if (xsetcolorname(j, p)) {
+			} else if (xsetcolorname(j, p)) {
 				if (par == 104 && narg <= 1)
 					return; /* color reset without parameter */
 				fprintf(stderr, "erresc: invalid color j=%d, p=%s\n",
@@ -1975,7 +1941,7 @@ strhandle(void)
 				 * TODO if defaultbg color is changed, borders
 				 * are dirty
 				 */
-				redraw();
+				tfulldirt();
 			}
 			return;
 		}
@@ -2674,7 +2640,8 @@ draw(void)
 
 	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]);
+			term.ocx, term.ocy, term.line[term.ocy][term.ocx],
+			term.line[term.ocy], term.col);
 	term.ocx = cx;
 	term.ocy = term.c.y;
 	xfinishdraw();

st.h

@@ -11,7 +11,8 @@
 #define DIVCEIL(n, d)		(((n) + ((d) - 1)) / (d))
 #define DEFAULT(a, b)		(a) = (a) ? (a) : (b)
 #define LIMIT(x, a, b)		(x) = (x) < (a) ? (a) : (x) > (b) ? (b) : (x)
-#define ATTRCMP(a, b)		((a).mode != (b).mode || (a).fg != (b).fg || \
+#define ATTRCMP(a, b)		(((a).mode & (~ATTR_WRAP)) != ((b).mode & (~ATTR_WRAP)) || \
+				(a).fg != (b).fg || \
 				(a).bg != (b).bg)
 #define TIMEDIFF(t1, t2)	((t1.tv_sec-t2.tv_sec)*1000 + \
 				(t1.tv_nsec-t2.tv_nsec)/1E6)
@@ -111,8 +112,6 @@ void *xmalloc(size_t);
 void *xrealloc(void *, size_t);
 char *xstrdup(const char *);
 
-int xgetcolor(int x, unsigned char *r, unsigned char *g, unsigned char *b);
-
 /* config.h globals */
 extern char *utmp;
 extern char *scroll;

win.h

@@ -25,11 +25,12 @@ enum win_mode {
 
 void xbell(void);
 void xclipcopy(void);
-void xdrawcursor(int, int, Glyph, int, int, Glyph);
+void xdrawcursor(int, int, Glyph, int, int, Glyph, Line, int);
 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);

x.c

@@ -19,6 +19,7 @@ char *argv0;
 #include "arg.h"
 #include "st.h"
 #include "win.h"
+#include "hb.h"
 
 /* types used in config.h */
 typedef struct {
@@ -141,8 +142,9 @@ typedef struct {
 } DC;
 
 static inline ushort sixd_to_16bit(int);
+static void xresetfontsettings(ushort mode, Font **font, int *frcflags);
 static int xmakeglyphfontspecs(XftGlyphFontSpec *, const Glyph *, int, int, int);
-static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int);
+static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int, int);
 static void xdrawglyph(Glyph, int, int);
 static void xclear(int, int, int, int);
 static int xgeommasktogravity(int);
@@ -757,7 +759,7 @@ xresize(int col, int row)
 	xclear(0, 0, win.w, win.h);
 
 	/* resize to new width */
-	xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec));
+	xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec) * 4);
 }
 
 ushort
@@ -1062,6 +1064,9 @@ xunloadfont(Font *f)
 void
 xunloadfonts(void)
 {
+	/* Clear Harfbuzz font cache. */
+	hbunloadfonts();
+
 	/* Free the loaded fonts in the font cache.  */
 	while (frclen > 0)
 		XftFontClose(xw.dpy, frc[--frclen].font);
@@ -1185,7 +1190,7 @@ xinit(int cols, int rows)
 	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
 
 	/* font spec buffer */
-	xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec));
+	xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec) * 4);
 
 	/* Xft rendering context */
 	xw.draw = XftDrawCreate(xw.dpy, xw.buf, xw.vis, xw.cmap);
@@ -1239,6 +1244,22 @@ xinit(int cols, int rows)
 		xsel.xtarget = XA_STRING;
 }
 
+void
+xresetfontsettings(ushort mode, Font **font, int *frcflags)
+{
+	*font = &dc.font;
+	if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD)) {
+		*font = &dc.ibfont;
+		*frcflags = FRC_ITALICBOLD;
+	} else if (mode & ATTR_ITALIC) {
+		*font = &dc.ifont;
+		*frcflags = FRC_ITALIC;
+	} else if (mode & ATTR_BOLD) {
+		*font = &dc.bfont;
+		*frcflags = FRC_BOLD;
+	}
+}
+
 int
 xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x, int y)
 {
@@ -1253,49 +1274,65 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
 	FcPattern *fcpattern, *fontpattern;
 	FcFontSet *fcsets[] = { NULL };
 	FcCharSet *fccharset;
-	int i, f, numspecs = 0;
+	int i, f, length = 0, start = 0, numspecs = 0;
+	float cluster_xp = xp, cluster_yp = yp;
+	HbTransformData shaped = { 0 };
+
+	/* Initial values. */
+	mode = prevmode = glyphs[0].mode & ~ATTR_WRAP;
+	xresetfontsettings(mode, &font, &frcflags);
 
 	for (i = 0, xp = winx, yp = winy + font->ascent; i < len; ++i) {
-		/* Fetch rune and mode for current glyph. */
+		mode = glyphs[i].mode & ~ATTR_WRAP;
-		rune = glyphs[i].u;
-		mode = glyphs[i].mode;
 
 		/* Skip dummy wide-character spacing. */
-		if (mode == ATTR_WDUMMY)
+		if (mode & ATTR_WDUMMY && i < (len - 1))
 			continue;
 
-		/* Determine font for glyph if different from previous glyph. */
+		if (
-		if (prevmode != mode) {
+			prevmode != mode
-			prevmode = mode;
+			|| ATTRCMP(glyphs[start], glyphs[i])
-			font = &dc.font;
+			|| selected(x + i, y) != selected(x + start, y)
-			frcflags = FRC_NORMAL;
+			|| i == (len - 1)
-			runewidth = win.cw * ((mode & ATTR_WIDE) ? 2.0f : 1.0f);
+		) {
-			if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD)) {
+			/* Handle 1-character wide segments and end of line */
-				font = &dc.ibfont;
+			length = i - start;
-				frcflags = FRC_ITALICBOLD;
+			if (i == start) {
-			} else if (mode & ATTR_ITALIC) {
+				length = 1;
-				font = &dc.ifont;
+			} else if (i == (len - 1)) {
-				frcflags = FRC_ITALIC;
+				length = (i - start + 1);
-			} else if (mode & ATTR_BOLD) {
-				font = &dc.bfont;
-				frcflags = FRC_BOLD;
-			}
-			yp = winy + font->ascent;
 			}
 
-		/* Lookup character index with default font. */
+			/* Shape the segment. */
-		glyphidx = XftCharIndex(xw.dpy, font->match, rune);
+			hbtransform(&shaped, font->match, glyphs, start, length);
-		if (glyphidx) {
+			runewidth = win.cw * ((glyphs[start].mode & ATTR_WIDE) ? 2.0f : 1.0f);
-			specs[numspecs].font = font->match;
+			cluster_xp = xp; cluster_yp = yp;
-			specs[numspecs].glyph = glyphidx;
+			for (int code_idx = 0; code_idx < shaped.count; code_idx++) {
-			specs[numspecs].x = (short)xp;
+				int idx = shaped.glyphs[code_idx].cluster;
-			specs[numspecs].y = (short)yp;
+
+				if (glyphs[start + idx].mode & ATTR_WDUMMY)
+					continue;
+
+				/* Advance the drawing cursor if we've moved to a new cluster */
+				if (code_idx > 0 && idx != shaped.glyphs[code_idx - 1].cluster) {
 					xp += runewidth;
-			numspecs++;
+					cluster_xp = xp;
-			continue;
+					cluster_yp = yp;
+					runewidth = win.cw * ((glyphs[start + idx].mode & ATTR_WIDE) ? 2.0f : 1.0f);
 				}
 
-		/* Fallback on font cache, search the font cache for match. */
+				if (shaped.glyphs[code_idx].codepoint != 0) {
+					/* If symbol is found, put it into the specs. */
+					specs[numspecs].font = font->match;
+					specs[numspecs].glyph = shaped.glyphs[code_idx].codepoint;
+					specs[numspecs].x = cluster_xp + (short)(shaped.positions[code_idx].x_offset / 64.);
+					specs[numspecs].y = cluster_yp - (short)(shaped.positions[code_idx].y_offset / 64.);
+					cluster_xp += shaped.positions[code_idx].x_advance / 64.;
+					cluster_yp += shaped.positions[code_idx].y_advance / 64.;
+					numspecs++;
+				} else {
+					/* If it's not found, try to fetch it through the font cache. */
+					rune = glyphs[start + idx].u;
 					for (f = 0; f < frclen; f++) {
 						glyphidx = XftCharIndex(xw.dpy, frc[f].font, rune);
 						/* Everything correct. */
@@ -1364,17 +1401,29 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
 					specs[numspecs].glyph = glyphidx;
 					specs[numspecs].x = (short)xp;
 					specs[numspecs].y = (short)yp;
-		xp += runewidth;
 					numspecs++;
 				}
+			}
+
+			/* Cleanup and get ready for next segment. */
+			hbcleanup(&shaped);
+			start = i;
+
+			/* Determine font for glyph if different from previous glyph. */
+			if (prevmode != mode) {
+				prevmode = mode;
+				xresetfontsettings(mode, &font, &frcflags);
+				yp = winy + font->ascent;
+			}
+		}
+	}
 
 	return numspecs;
 }
 
 void
-xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, int y)
+xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, int y, int charlen)
 {
-	int charlen = len * ((base.mode & ATTR_WIDE) ? 2 : 1);
 	int winx = borderpx + x * win.cw, winy = borderpx + y * win.ch,
 	    width = charlen * win.cw;
 	Color *fg, *bg, *temp, revfg, revbg, truefg, truebg;
@@ -1493,12 +1542,12 @@ 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);
 	}
 
@@ -1510,21 +1559,24 @@ void
 xdrawglyph(Glyph g, int x, int y)
 {
 	int numspecs;
-	XftGlyphFontSpec spec;
+	XftGlyphFontSpec *specs = xw.specbuf;
 
-	numspecs = xmakeglyphfontspecs(&spec, &g, 1, x, y);
+	numspecs = xmakeglyphfontspecs(specs, &g, 1, x, y);
-	xdrawglyphfontspecs(&spec, g, numspecs, x, y);
+	xdrawglyphfontspecs(specs, g, numspecs, x, y, (g.mode & ATTR_WIDE) ? 2 : 1);
 }
 
 void
-xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
+xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og, Line line, int len)
 {
 	Color drawcol;
 
 	/* remove the old cursor */
 	if (selected(ox, oy))
 		og.mode ^= ATTR_REVERSE;
-	xdrawglyph(og, ox, oy);
+
+	/* Redraw the line where cursor was previously.
+	 * It will restore the ligatures broken by the cursor. */
+	xdrawline(line, 0, oy, len);
 
 	if (IS_SET(MODE_HIDE))
 		return;
@@ -1652,18 +1704,16 @@ xdrawline(Line line, int x1, int y1, int x2)
 	Glyph base, new;
 	XftGlyphFontSpec *specs = xw.specbuf;
 
-	numspecs = xmakeglyphfontspecs(specs, &line[x1], x2 - x1, x1, y1);
 	i = ox = 0;
-	for (x = x1; x < x2 && i < numspecs; x++) {
+	for (x = x1; x < x2; x++) {
 		new = line[x];
 		if (new.mode == ATTR_WDUMMY)
 			continue;
 		if (selected(x, y1))
 			new.mode ^= ATTR_REVERSE;
-		if (i > 0 && ATTRCMP(base, new)) {
+		if ((i > 0) && ATTRCMP(base, new)) {
-			xdrawglyphfontspecs(specs, base, i, ox, y1);
+			numspecs = xmakeglyphfontspecs(specs, &line[ox], x - ox, ox, y1);
-			specs += i;
+			xdrawglyphfontspecs(specs, base, numspecs, ox, y1, x - ox);
-			numspecs -= i;
 			i = 0;
 		}
 		if (i == 0) {
@@ -1672,8 +1722,10 @@ xdrawline(Line line, int x1, int y1, int x2)
 		}
 		i++;
 	}
-	if (i > 0)
+	if (i > 0) {
-		xdrawglyphfontspecs(specs, base, i, ox, y1);
+		numspecs = xmakeglyphfontspecs(specs, &line[ox], x2 - ox, ox, y1);
+		xdrawglyphfontspecs(specs, base, numspecs, ox, y1, x2 - ox);
+	}
 }
 
 void