Added .gitignore

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.mk

@@ -1,5 +1,5 @@
 # st version
-VERSION = 0.8.5
+VERSION = 0.9
 
 # Customize below to fit your system
 
@@ -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);
 			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);
-
+	n = snprintf(buf, sizeof buf, "\033]%s%d;rgb:%02x%02x/%02x%02x/%02x%02x\007",
+	             is_osc4 ? "4;" : "", num, r, r, g, g, b, b);
+	if (n < 0 || n >= sizeof(buf)) {
+		fprintf(stderr, "error: %s while printing %s response\n",
+		        n < 0 ? "snprintf failed" : "truncation occurred",
+		        is_osc4 ? "osc4" : "osc");
+	} else {
 		ttywrite(buf, n, 1);
-}
-
-void
-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
@@ -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;

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

@@ -1833,7 +1833,7 @@ void
 kpress(XEvent *ev)
 {
 	XKeyEvent *e = &ev->xkey;
-	KeySym ksym;
+	KeySym ksym = NoSymbol;
 	char buf[64], *customkey;
 	int len;
 	Rune c;
@@ -1843,10 +1843,13 @@ 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)) {