support colons in SGR character attributes

Patch by Mikhail Kot <to@myrrc.dev>
With some modifications to behave more like xterm (see note below).

Example:

	printf '\033[48;2;255:0:0mtest\n'

https://invisible-island.net/xterm/ctlseqs/ctlseqs.html

Some notes:

"CSI Pm m  Character Attributes (SGR).
[...]
o   xterm allows either colons (standard) or semicolons
(legacy) to separate the subparameters (but after the
first colon, colons must be used).

config.def.h

@@ -53,7 +53,7 @@ int allowwindowops = 0;
  * 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 = 8;
+static double minlatency = 2;
 static double maxlatency = 33;
 
 /*

config.mk

@@ -1,5 +1,5 @@
 # st version
-VERSION = 0.9
+VERSION = 0.9.2
 
 # Customize below to fit your system
 

st.c

@@ -1132,6 +1132,7 @@ csiparse(void)
 {
 	char *p = csiescseq.buf, *np;
 	long int v;
+	int sep = ';'; /* colon or semi-colon, but not both */
 
 	csiescseq.narg = 0;
 	if (*p == '?') {
@@ -1149,7 +1150,9 @@ csiparse(void)
 			v = -1;
 		csiescseq.arg[csiescseq.narg++] = v;
 		p = np;
-		if (*p != ';' || csiescseq.narg == ESC_ARG_SIZ)
+		if (sep == ';' && *p == ':')
+			sep = ':'; /* allow override to colon once */
+		if (*p != sep || csiescseq.narg == ESC_ARG_SIZ)
 			break;
 		p++;
 	}
@@ -1643,7 +1646,7 @@ csihandle(void)
 			ttywrite(vtiden, strlen(vtiden), 0);
 		break;
 	case 'b': /* REP -- if last char is printable print it <n> more times */
-		DEFAULT(csiescseq.arg[0], 1);
+		LIMIT(csiescseq.arg[0], 1, 65535);
 		if (term.lastc)
 			while (csiescseq.arg[0]-- > 0)
 				tputc(term.lastc);
@@ -1728,6 +1731,7 @@ csihandle(void)
 		}
 		break;
 	case 'S': /* SU -- Scroll <n> line up */
+		if (csiescseq.priv) break;
 		DEFAULT(csiescseq.arg[0], 1);
 		tscrollup(term.top, csiescseq.arg[0]);
 		break;

st.info

@@ -184,6 +184,10 @@ 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)

x.c

@@ -1617,6 +1617,9 @@ 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;
@@ -1631,6 +1634,9 @@ xsettitle(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;