Added alpha patch v0.8.5

Ignore processing and printing C1 control characters in UTF-8 mode.
These are in the range: 0x80 - 0x9f.

By default in st the mode is set to UTF-8.

This matches more the behaviour of xterm with the options -u8 or +u8 also.
Also see the xterm resource "allowC1Printable".

Let me know if this breaks something, in most cases I don't think so.

As usual a very good reference is:
https://invisible-island.net/xterm/ctlseqs/ctlseqs.html

.gitignore

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

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

config.def.h

@@ -93,6 +93,9 @@ char *termname = "st-256color";
  */
 unsigned int tabspaces = 8;
 
+/* bg opacity */
+float alpha = 0.8;
+
 /* Terminal colors (16 first used in escape sequence) */
 static const char *colorname[] = {
 	/* 8 normal colors */

config.mk

@@ -1,5 +1,5 @@
 # st version
-VERSION = 0.8.5
+VERSION = 0.9
 
 # Customize below to fit your system
 
@@ -16,7 +16,7 @@ PKG_CONFIG = pkg-config
 INCS = -I$(X11INC) \
        `$(PKG_CONFIG) --cflags fontconfig` \
        `$(PKG_CONFIG) --cflags freetype2`
-LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
+LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft -lXrender\
        `$(PKG_CONFIG) --libs fontconfig` \
        `$(PKG_CONFIG) --libs freetype2`
 
@@ -30,6 +30,7 @@ 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

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);
@@ -938,7 +939,7 @@ ttyresize(int tw, int th)
 }
 
 void
-ttyhangup()
+ttyhangup(void)
 {
 	/* Send SIGHUP to shell */
 	kill(pid, SIGHUP);
@@ -1768,11 +1769,18 @@ csihandle(void)
 	case 'm': /* SGR -- Terminal attribute (color) */
 		tsetattr(csiescseq.arg, csiescseq.narg);
 		break;
-	case 'n': /* DSR – Device Status Report (cursor position) */
-		if (csiescseq.arg[0] == 6) {
+	case 'n': /* DSR -- Device Status Report */
+		switch (csiescseq.arg[0]) {
+		case 5: /* Status Report "OK" `0n` */
+			ttywrite("\033[0n", sizeof("\033[0n") - 1, 0);
+			break;
+		case 6: /* Report Cursor Position (CPR) "<row>;<column>R" */
 			len = snprintf(buf, sizeof(buf), "\033[%i;%iR",
-					term.c.y+1, term.c.x+1);
+			               term.c.y+1, term.c.x+1);
 			ttywrite(buf, len, 0);
+			break;
+		default:
+			goto unknown;
 		}
 		break;
 	case 'r': /* DECSTBM -- Set Scrolling Region */
@@ -1835,39 +1843,28 @@ 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)) {
-		fprintf(stderr, "erresc: failed to fetch osc4 color %d\n", num);
+	if (xgetcolor(is_osc4 ? num : index, &r, &g, &b)) {
+		fprintf(stderr, "erresc: failed to fetch %s color %d\n",
+		        is_osc4 ? "osc4" : "osc",
+		        is_osc4 ? num : index);
 		return;
 	}
 
-	n = snprintf(buf, sizeof buf, "\033]4;%d;rgb:%02x%02x/%02x%02x/%02x%02x\007",
-		     num, r, r, g, g, b, b);
-
-	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]%s%d;rgb:%02x%02x/%02x%02x/%02x%02x\007",
+	             is_osc4 ? "4;" : "", num, r, r, g, g, b, b);
+	if (n < 0 || n >= sizeof(buf)) {
+		fprintf(stderr, "error: %s while printing %s response\n",
+		        n < 0 ? "snprintf failed" : "truncation occurred",
+		        is_osc4 ? "osc4" : "osc");
+	} else {
+		ttywrite(buf, n, 1);
 	}
-
-	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
@@ -1875,6 +1872,11 @@ 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();
@@ -1909,43 +1911,22 @@ 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
-				tfulldirt();
-			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
-				tfulldirt();
-			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, "?"))
-				osc_color_response(defaultcs, 12);
-			else if (xsetcolorname(defaultcs, p))
-				fprintf(stderr, "erresc: invalid cursor color: %s\n", p);
-			else
+			if (!strcmp(p, "?")) {
+				osc_color_response(par, osc_table[j].idx, 0);
+			} else if (xsetcolorname(osc_table[j].idx, p)) {
+				fprintf(stderr, "erresc: invalid %s color: %s\n",
+				        osc_table[j].str, p);
+			} else {
 				tfulldirt();
+			}
 			return;
 		case 4: /* color set */
 			if (narg < 3)
@@ -1955,11 +1936,13 @@ strhandle(void)
 		case 104: /* color reset */
 			j = (narg > 1) ? atoi(strescseq.args[1]) : -1;
 
-			if (p && !strcmp(p, "?"))
-				osc4_color_response(j);
-			else if (xsetcolorname(j, p)) {
-				if (par == 104 && narg <= 1)
+			if (p && !strcmp(p, "?")) {
+				osc_color_response(j, 0, 1);
+			} else if (xsetcolorname(j, p)) {
+				if (par == 104 && narg <= 1) {
+					xloadcols();
 					return; /* color reset without parameter */
+				}
 				fprintf(stderr, "erresc: invalid color j=%d, p=%s\n",
 				        j, p ? p : "(null)");
 			} else {
@@ -2439,6 +2422,9 @@ check_control_code:
 	 * they must not cause conflicts with sequences.
 	 */
 	if (control) {
+		/* in UTF-8 mode ignore handling C1 control characters */
+		if (IS_SET(MODE_UTF8) && ISCONTROLC1(u))
+			return;
 		tcontrolcode(u);
 		/*
 		 * control codes are not shown ever

st.h

@@ -111,8 +111,6 @@ 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;
@@ -126,3 +124,4 @@ extern unsigned int tabspaces;
 extern unsigned int defaultfg;
 extern unsigned int defaultbg;
 extern unsigned int defaultcs;
+extern float alpha;

win.h

@@ -30,6 +30,7 @@ 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

@@ -105,6 +105,7 @@ typedef struct {
 	XSetWindowAttributes attrs;
 	int scr;
 	int isfixed; /* is fixed geometry? */
+	int depth; /* bit depth */
 	int l, t; /* left and top offset */
 	int gm; /* geometry mask */
 } XWindow;
@@ -243,6 +244,7 @@ static char *usedfont = NULL;
 static double usedfontsize = 0;
 static double defaultfontsize = 0;
 
+static char *opt_alpha = NULL;
 static char *opt_class = NULL;
 static char **opt_cmd  = NULL;
 static char *opt_embed = NULL;
@@ -752,7 +754,7 @@ xresize(int col, int row)
 
 	XFreePixmap(xw.dpy, xw.buf);
 	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
-			DefaultDepth(xw.dpy, xw.scr));
+			xw.depth);
 	XftDrawChange(xw.draw, xw.buf);
 	xclear(0, 0, win.w, win.h);
 
@@ -812,6 +814,13 @@ xloadcols(void)
 			else
 				die("could not allocate color %d\n", i);
 		}
+
+	/* set alpha value of bg color */
+	if (opt_alpha)
+		alpha = strtof(opt_alpha, NULL);
+	dc.col[defaultbg].color.alpha = (unsigned short)(0xffff * alpha);
+	dc.col[defaultbg].pixel &= 0x00FFFFFF;
+	dc.col[defaultbg].pixel |= (unsigned char)(0xff * alpha) << 24;
 	loaded = 1;
 }
 
@@ -1134,11 +1143,23 @@ xinit(int cols, int rows)
 	Window parent;
 	pid_t thispid = getpid();
 	XColor xmousefg, xmousebg;
+	XWindowAttributes attr;
+	XVisualInfo vis;
 
 	if (!(xw.dpy = XOpenDisplay(NULL)))
 		die("can't open display\n");
 	xw.scr = XDefaultScreen(xw.dpy);
-	xw.vis = XDefaultVisual(xw.dpy, xw.scr);
+
+	if (!(opt_embed && (parent = strtol(opt_embed, NULL, 0)))) {
+		parent = XRootWindow(xw.dpy, xw.scr);
+		xw.depth = 32;
+	} else {
+		XGetWindowAttributes(xw.dpy, parent, &attr);
+		xw.depth = attr.depth;
+	}
+
+	XMatchVisualInfo(xw.dpy, xw.scr, xw.depth, TrueColor, &vis);
+	xw.vis = vis.visual;
 
 	/* font */
 	if (!FcInit())
@@ -1148,7 +1169,7 @@ xinit(int cols, int rows)
 	xloadfonts(usedfont, 0);
 
 	/* colors */
-	xw.cmap = XDefaultColormap(xw.dpy, xw.scr);
+	xw.cmap = XCreateColormap(xw.dpy, parent, xw.vis, None);
 	xloadcols();
 
 	/* adjust fixed window geometry */
@@ -1168,19 +1189,15 @@ xinit(int cols, int rows)
 		| ButtonMotionMask | ButtonPressMask | ButtonReleaseMask;
 	xw.attrs.colormap = xw.cmap;
 
-	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,
-			win.w, win.h, 0, XDefaultDepth(xw.dpy, xw.scr), InputOutput,
+			win.w, win.h, 0, xw.depth, InputOutput,
 			xw.vis, CWBackPixel | CWBorderPixel | CWBitGravity
 			| CWEventMask | CWColormap, &xw.attrs);
 
 	memset(&gcvalues, 0, sizeof(gcvalues));
 	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 = XCreatePixmap(xw.dpy, xw.win, win.w, win.h, xw.depth);
+	dc.gc = XCreateGC(xw.dpy, xw.buf, GCGraphicsExposures, &gcvalues);
 	XSetForeground(xw.dpy, dc.gc, dc.col[defaultbg].pixel);
 	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
 
@@ -1833,7 +1850,7 @@ void
 kpress(XEvent *ev)
 {
 	XKeyEvent *e = &ev->xkey;
-	KeySym ksym;
+	KeySym ksym = NoSymbol;
 	char buf[64], *customkey;
 	int len;
 	Rune c;
@@ -1843,10 +1860,13 @@ 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)) {
@@ -2035,6 +2055,9 @@ main(int argc, char *argv[])
 	case 'a':
 		allowaltscreen = 0;
 		break;
+	case 'A':
+		opt_alpha = EARGF(usage());
+		break;
 	case 'c':
 		opt_class = EARGF(usage());
 		break;