Adding the CSI 22, 23 patch

README.md

@@ -15,6 +15,8 @@ Refer to [https://st.suckless.org/](https://st.suckless.org/) for details on the
 
 ### Changelog:
 
+2021-08-18 - Added the CSI 22 & 23 patch
+
 2021-07-26 - Added columns patch
 
 2021-07-07 - Added sixel scrollback and the openurlonclick patch
@@ -88,7 +90,8 @@ Refer to [https://st.suckless.org/](https://st.suckless.org/) for details on the
       - allows st to reize to any pixel size rather than snapping to character width / height
 
    - [anysize_nobar](https://github.com/connor-brooks/st-anysize-nobar)
-      - a patch that aims to prevent black bars being drawn on the edges of st terminals using the anysize patch
+      - a patch that aims to prevent black bars being drawn on the edges of st terminals using the
+        anysize patch
 
    - [blinking-cursor](https://st.suckless.org/patches/blinking_cursor/)
       - allows the use of a blinking cursor
@@ -112,6 +115,10 @@ Refer to [https://st.suckless.org/](https://st.suckless.org/) for details on the
       - this patch allows you to select and copy the last URL displayed with Mod+l
       - multiple invocations cycle through the available URLs
 
+   - [csi_23_23](https://st.suckless.org/patches/csi_22_23/)
+      - adds support for CSI escape sequences 22 and 23, which save and restores the window title
+        (for instance nvim does this when opening and closing)
+
    - default-cursor
       - minor change allowing escape sequences like `\e[ q` or `\e[0 q` to set the cursor back to default configuration instead of a blinking block
       - while many terminals do this the behaviour is not according to the specification

patches.def.h

@@ -94,6 +94,12 @@
  */
 #define COPYURL_HIGHLIGHT_SELECTED_URLS_PATCH 0
 
+/* This patch adds support for CSI escape sequences 22 and 23, which save and
+ * restores the window title (for instance nvim does this when opening and closing).
+ * https://st.suckless.org/patches/csi_22_23/
+ */
+#define CSI_22_23_PATCH 0
+
 /* According to the specification (see link in BLINKING_CURSOR_PATCH) the "Set cursor style
  * (DECSCUSR), VT520." escape sequences define both values of 0 and 1 as a blinking block,
  * with 1 being the default.

st.c

@@ -2314,6 +2314,36 @@ csihandle(void)
 	case 's': /* DECSC -- Save cursor position (ANSI.SYS) */
 		tcursor(CURSOR_SAVE);
 		break;
+	#if CSI_22_23_PATCH
+	case 't': /* title stack operations */
+		switch (csiescseq.arg[0]) {
+		case 22: /* pust current title on stack */
+			switch (csiescseq.arg[1]) {
+			case 0:
+			case 1:
+			case 2:
+				xpushtitle();
+				break;
+			default:
+				goto unknown;
+			}
+			break;
+		case 23: /* pop last title from stack */
+			switch (csiescseq.arg[1]) {
+			case 0:
+			case 1:
+			case 2:
+				xsettitle(NULL, 1);
+				break;
+			default:
+				goto unknown;
+			}
+			break;
+		default:
+			goto unknown;
+		}
+		break;
+	#endif // CSI_22_23_PATCH
 	case 'u': /* DECRC -- Restore cursor position (ANSI.SYS) */
 		tcursor(CURSOR_LOAD);
 		break;
@@ -2379,7 +2409,11 @@ strhandle(void)
 		switch (par) {
 		case 0:
 			if (narg > 1) {
+				#if CSI_22_23_PATCH
+				xsettitle(strescseq.args[1], 0);
+				#else
 				xsettitle(strescseq.args[1]);
+				#endif // CSI_22_23_PATCH
 				xseticontitle(strescseq.args[1]);
 			}
 			return;
@@ -2389,7 +2423,11 @@ strhandle(void)
 			return;
 		case 2:
 			if (narg > 1)
+				#if CSI_22_23_PATCH
+				xsettitle(strescseq.args[1], 0);
+				#else
 				xsettitle(strescseq.args[1]);
+				#endif // CSI_22_23_PATCH
 			return;
 		case 52:
 			if (narg > 2 && allowwindowops) {
@@ -2469,7 +2507,11 @@ strhandle(void)
 		}
 		break;
 	case 'k': /* old title set compatibility */
+		#if CSI_22_23_PATCH
+		xsettitle(strescseq.args[0], 0);
+		#else
 		xsettitle(strescseq.args[0]);
+		#endif // CSI_22_23_PATCH
 		return;
 	case 'P': /* DCS -- Device Control String */
 		#if SIXEL_PATCH
@@ -2905,6 +2947,9 @@ eschandle(uchar ascii)
 		break;
 	case 'c': /* RIS -- Reset to initial state */
 		treset();
+		#if CSI_22_23_PATCH
+		xfreetitlestack();
+		#endif // CSI_22_23_PATCH
 		resettitle();
 		xloadcols();
 		break;
@@ -3326,7 +3371,11 @@ tresize(int col, int row)
 void
 resettitle(void)
 {
+	#if CSI_22_23_PATCH
+	xsettitle(NULL, 0);
+	#else
 	xsettitle(NULL);
+	#endif // CSI_22_23_PATCH
 }
 
 void

win.h

@@ -41,7 +41,13 @@ void xfinishdraw(void);
 void xloadcols(void);
 int xsetcolorname(int, const char *);
 void xseticontitle(char *);
+#if CSI_22_23_PATCH
+void xfreetitlestack(void);
+void xsettitle(char *, int);
+void xpushtitle(void);
+#else
 void xsettitle(char *);
+#endif // CSI_22_23_PATCH
 int xsetcursor(int);
 void xsetmode(int, unsigned int);
 void xsetpointermotion(int);

x.c

@@ -48,6 +48,11 @@ static void zoomreset(const Arg *);
 /* config.h for applying patches and the configuration. */
 #include "config.h"
 
+#if CSI_22_23_PATCH
+/* size of title stack */
+#define TITLESTACKSIZE 8
+#endif // CSI_22_23_PATCH
+
 /* XEMBED messages */
 #define XEMBED_FOCUS_IN  4
 #define XEMBED_FOCUS_OUT 5
@@ -148,6 +153,11 @@ XWindow xw;
 XSelection xsel;
 TermWindow win;
 
+#if CSI_22_23_PATCH
+static int tstki; /* title stack index */
+static char *titlestack[TITLESTACKSIZE]; /* title stack */
+#endif // CSI_22_23_PATCH
+
 /* Font Ring Cache */
 enum {
 	FRC_NORMAL,
@@ -2189,6 +2199,49 @@ xseticontitle(char *p)
 	XFree(prop.value);
 }
 
+#if CSI_22_23_PATCH
+void
+xsettitle(char *p, int pop)
+{
+	XTextProperty prop;
+
+	free(titlestack[tstki]);
+	if (pop) {
+		titlestack[tstki] = NULL;
+		tstki = (tstki - 1 + TITLESTACKSIZE) % TITLESTACKSIZE;
+		p = titlestack[tstki] ? titlestack[tstki] : opt_title;
+	} else if (p) {
+		titlestack[tstki] = xstrdup(p);
+	} else {
+		titlestack[tstki] = NULL;
+		p = opt_title;
+	}
+
+	Xutf8TextListToTextProperty(xw.dpy, &p, 1, XUTF8StringStyle, &prop);
+	XSetWMName(xw.dpy, xw.win, &prop);
+	XSetTextProperty(xw.dpy, xw.win, &prop, xw.netwmname);
+	XFree(prop.value);
+}
+
+void
+xpushtitle(void)
+{
+	int tstkin = (tstki + 1) % TITLESTACKSIZE;
+
+	free(titlestack[tstkin]);
+	titlestack[tstkin] = titlestack[tstki] ? xstrdup(titlestack[tstki]) : NULL;
+	tstki = tstkin;
+}
+
+void
+xfreetitlestack(void)
+{
+	for (int i = 0; i < LEN(titlestack); i++) {
+		free(titlestack[i]);
+		titlestack[i] = NULL;
+	}
+}
+#else
 void
 xsettitle(char *p)
 {
@@ -2201,6 +2254,7 @@ xsettitle(char *p)
 	XSetTextProperty(xw.dpy, xw.win, &prop, xw.netwmname);
 	XFree(prop.value);
 }
+#endif // CSI_22_23_PATCH
 
 int
 xstartdraw(void)