From 895e5b50a8cc835c19a45e1e328eb4dc78f5fd0c Mon Sep 17 00:00:00 2001
From: Ivan Tham <pickfire@riseup.net>
Date: Sat, 18 Jan 2020 15:52:25 +0800
Subject: [PATCH 01/46] Increase XmbLookupString buffer
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Current buffer is too short to input medium to long sentences from IME.
Input with longer text will show the wrong input, taking 64 instead of
32 bytes should be enough for most of the cases. Broken cases before,

Chinese (taken from song 也可以)
可不可以轻轻的松开自己

Japanese (taken from bootleggers rom quote)
あなたは家のように感じる
---
 x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/x.c b/x.c
index bc3ad5a..e000894 100644
--- a/x.c
+++ b/x.c
@@ -1743,7 +1743,7 @@ kpress(XEvent *ev)
 {
 	XKeyEvent *e = &ev->xkey;
 	KeySym ksym;
-	char buf[32], *customkey;
+	char buf[64], *customkey;
 	int len;
 	Rune c;
 	Status status;

From 99de33395126fc9708f442d155e737b9182f6ef4 Mon Sep 17 00:00:00 2001
From: Quentin Rameau <quinq@fifth.space>
Date: Sun, 2 Feb 2020 15:37:29 +0100
Subject: [PATCH 02/46] x: move IME variables into XWindow ime embedded struct

---
 x.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/x.c b/x.c
index e000894..60eeee1 100644
--- a/x.c
+++ b/x.c
@@ -94,8 +94,10 @@ typedef struct {
 	Drawable buf;
 	GlyphFontSpec *specbuf; /* font spec buffer used for rendering */
 	Atom xembed, wmdeletewin, netwmname, netwmpid;
-	XIM xim;
-	XIC xic;
+	struct {
+		XIM xim;
+		XIC xic;
+	} ime;
 	Draw draw;
 	Visual *vis;
 	XSetWindowAttributes attrs;
@@ -1026,18 +1028,18 @@ ximopen(Display *dpy)
 {
 	XIMCallback destroy = { .client_data = NULL, .callback = ximdestroy };
 
-	if ((xw.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
+	if ((xw.ime.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
 		XSetLocaleModifiers("@im=local");
-		if ((xw.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
+		if ((xw.ime.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
 			XSetLocaleModifiers("@im=");
-			if ((xw.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL)
+			if ((xw.ime.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL)
 				die("XOpenIM failed. Could not open input device.\n");
 		}
 	}
-	if (XSetIMValues(xw.xim, XNDestroyCallback, &destroy, NULL) != NULL)
+	if (XSetIMValues(xw.ime.xim, XNDestroyCallback, &destroy, NULL) != NULL)
 		die("XSetIMValues failed. Could not set input method value.\n");
-	xw.xic = XCreateIC(xw.xim, XNInputStyle, XIMPreeditNothing | XIMStatusNothing,
-				XNClientWindow, xw.win, XNFocusWindow, xw.win, NULL);
+	xw.xic = XCreateIC(xw.ime.xim, XNInputStyle, XIMPreeditNothing | XIMStatusNothing,
+	                   XNClientWindow, xw.win, XNFocusWindow, xw.win, NULL);
 	if (xw.xic == NULL)
 		die("XCreateIC failed. Could not obtain input method.\n");
 }
@@ -1053,7 +1055,7 @@ ximinstantiate(Display *dpy, XPointer client, XPointer call)
 void
 ximdestroy(XIM xim, XPointer client, XPointer call)
 {
-	xw.xim = NULL;
+	xw.ime.xim = NULL;
 	XRegisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
 					ximinstantiate, NULL);
 }
@@ -1682,13 +1684,13 @@ focus(XEvent *ev)
 		return;
 
 	if (ev->type == FocusIn) {
-		XSetICFocus(xw.xic);
+		XSetICFocus(xw.ime.xic);
 		win.mode |= MODE_FOCUSED;
 		xseturgency(0);
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[I", 3, 0);
 	} else {
-		XUnsetICFocus(xw.xic);
+		XUnsetICFocus(xw.ime.xic);
 		win.mode &= ~MODE_FOCUSED;
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[O", 3, 0);
@@ -1752,7 +1754,7 @@ kpress(XEvent *ev)
 	if (IS_SET(MODE_KBDLOCK))
 		return;
 
-	len = XmbLookupString(xw.xic, e, buf, sizeof buf, &ksym, &status);
+	len = XmbLookupString(xw.ime.xic, e, buf, sizeof buf, &ksym, &status);
 	/* 1. shortcuts */
 	for (bp = shortcuts; bp < shortcuts + LEN(shortcuts); bp++) {
 		if (ksym == bp->keysym && match(bp->mod, e->state)) {

From 2cb539142b97bd2a5c1a322fd7c063c6afb67c9b Mon Sep 17 00:00:00 2001
From: Quentin Rameau <quinq@fifth.space>
Date: Sun, 2 Feb 2020 15:38:08 +0100
Subject: [PATCH 03/46] x: do not instantiate a new nested list on each cursor
 move

---
 x.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/x.c b/x.c
index 60eeee1..5af6e4d 100644
--- a/x.c
+++ b/x.c
@@ -97,6 +97,8 @@ typedef struct {
 	struct {
 		XIM xim;
 		XIC xic;
+		XPoint spot;
+		XVaNestedList spotlist;
 	} ime;
 	Draw draw;
 	Visual *vis;
@@ -1042,6 +1044,9 @@ ximopen(Display *dpy)
 	                   XNClientWindow, xw.win, XNFocusWindow, xw.win, NULL);
 	if (xw.xic == NULL)
 		die("XCreateIC failed. Could not obtain input method.\n");
+
+	xw.ime.spotlist = XVaCreateNestedList(0, XNSpotLocation, &xw.ime.spot,
+	                                      NULL);
 }
 
 void
@@ -1058,6 +1063,7 @@ ximdestroy(XIM xim, XPointer client, XPointer call)
 	xw.ime.xim = NULL;
 	XRegisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
 					ximinstantiate, NULL);
+	XFree(xw.ime.spotlist);
 }
 
 void
@@ -1603,11 +1609,13 @@ xfinishdraw(void)
 void
 xximspot(int x, int y)
 {
-	XPoint spot = { borderpx + x * win.cw, borderpx + (y + 1) * win.ch };
-	XVaNestedList attr = XVaCreateNestedList(0, XNSpotLocation, &spot, NULL);
+	if (xw.ime.xic == NULL)
+		return;
+
+	xw.ime.spot.x = borderpx + x * win.cw;
+	xw.ime.spot.y = borderpx + (y + 1) * win.ch;
 
-	XSetICValues(xw.xic, XNPreeditAttributes, attr, NULL);
-	XFree(attr);
+	XSetICValues(xw.ime.xic, XNPreeditAttributes, xw.ime.spotlist, NULL);
 }
 
 void

From cd785755f2e3e3305c7d2556a04423a40bce060a Mon Sep 17 00:00:00 2001
From: Quentin Rameau <quinq@fifth.space>
Date: Sun, 2 Feb 2020 17:38:36 +0100
Subject: [PATCH 04/46] x: check we still have an XIC context before accessing
 it

---
 x.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/x.c b/x.c
index 5af6e4d..b488617 100644
--- a/x.c
+++ b/x.c
@@ -1061,6 +1061,7 @@ void
 ximdestroy(XIM xim, XPointer client, XPointer call)
 {
 	xw.ime.xim = NULL;
+	xw.ime.xic = NULL;
 	XRegisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
 					ximinstantiate, NULL);
 	XFree(xw.ime.spotlist);
@@ -1692,13 +1693,15 @@ focus(XEvent *ev)
 		return;
 
 	if (ev->type == FocusIn) {
-		XSetICFocus(xw.ime.xic);
+		if (xw.ime.xic)
+			XSetICFocus(xw.ime.xic);
 		win.mode |= MODE_FOCUSED;
 		xseturgency(0);
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[I", 3, 0);
 	} else {
-		XUnsetICFocus(xw.ime.xic);
+		if (xw.ime.xic)
+			XUnsetICFocus(xw.ime.xic);
 		win.mode &= ~MODE_FOCUSED;
 		if (IS_SET(MODE_FOCUS))
 			ttywrite("\033[O", 3, 0);

From 26cdfebf31f024e331429e482b1ee342708888e3 Mon Sep 17 00:00:00 2001
From: Quentin Rameau <quinq@fifth.space>
Date: Sun, 2 Feb 2020 21:47:19 +0100
Subject: [PATCH 05/46] x: fix XIM handling

Do not try to set specific IM method, let the user specify it with
XMODIFIERS.

If the requested method is not available or opening fails, fallback to
the default input handler and register a handler on the new IM server
availability signal.

Do the same when the input server is closed and (re)started.
---
 x.c | 68 +++++++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 44 insertions(+), 24 deletions(-)

diff --git a/x.c b/x.c
index b488617..1f62129 100644
--- a/x.c
+++ b/x.c
@@ -146,9 +146,10 @@ static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int);
 static void xdrawglyph(Glyph, int, int);
 static void xclear(int, int, int, int);
 static int xgeommasktogravity(int);
-static void ximopen(Display *);
+static int ximopen(Display *);
 static void ximinstantiate(Display *, XPointer, XPointer);
 static void ximdestroy(XIM, XPointer, XPointer);
+static int xicdestroy(XIC, XPointer, XPointer);
 static void xinit(int, int);
 static void cresize(int, int);
 static void xresize(int, int);
@@ -1025,48 +1026,61 @@ xunloadfonts(void)
 	xunloadfont(&dc.ibfont);
 }
 
-void
+int
 ximopen(Display *dpy)
 {
-	XIMCallback destroy = { .client_data = NULL, .callback = ximdestroy };
+	XIMCallback imdestroy = { .client_data = NULL, .callback = ximdestroy };
+	XICCallback icdestroy = { .client_data = NULL, .callback = xicdestroy };
 
-	if ((xw.ime.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
-		XSetLocaleModifiers("@im=local");
-		if ((xw.ime.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
-			XSetLocaleModifiers("@im=");
-			if ((xw.ime.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL)
-				die("XOpenIM failed. Could not open input device.\n");
-		}
-	}
-	if (XSetIMValues(xw.ime.xim, XNDestroyCallback, &destroy, NULL) != NULL)
-		die("XSetIMValues failed. Could not set input method value.\n");
-	xw.xic = XCreateIC(xw.ime.xim, XNInputStyle, XIMPreeditNothing | XIMStatusNothing,
-	                   XNClientWindow, xw.win, XNFocusWindow, xw.win, NULL);
-	if (xw.xic == NULL)
-		die("XCreateIC failed. Could not obtain input method.\n");
+	xw.ime.xim = XOpenIM(xw.dpy, NULL, NULL, NULL);
+	if (xw.ime.xim == NULL)
+		return 0;
+
+	if (XSetIMValues(xw.ime.xim, XNDestroyCallback, &imdestroy, NULL))
+		fprintf(stderr, "XSetIMValues: "
+		                "Could not set XNDestroyCallback.\n");
 
 	xw.ime.spotlist = XVaCreateNestedList(0, XNSpotLocation, &xw.ime.spot,
 	                                      NULL);
+
+	if (xw.ime.xic == NULL) {
+		xw.ime.xic = XCreateIC(xw.ime.xim, XNInputStyle,
+		                       XIMPreeditNothing | XIMStatusNothing,
+		                       XNClientWindow, xw.win,
+		                       XNFocusWindow, xw.win,
+		                       XNDestroyCallback, &icdestroy,
+		                       NULL);
+	}
+	if (xw.ime.xic == NULL)
+		fprintf(stderr, "XCreateIC: Could not create input context.\n");
+
+	return 1;
 }
 
 void
 ximinstantiate(Display *dpy, XPointer client, XPointer call)
 {
-	ximopen(dpy);
-	XUnregisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
-					ximinstantiate, NULL);
+	if (ximopen(dpy))
+		XUnregisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
+		                                 ximinstantiate, NULL);
 }
 
 void
 ximdestroy(XIM xim, XPointer client, XPointer call)
 {
 	xw.ime.xim = NULL;
-	xw.ime.xic = NULL;
 	XRegisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
-					ximinstantiate, NULL);
+	                               ximinstantiate, NULL);
 	XFree(xw.ime.spotlist);
 }
 
+int
+xicdestroy(XIC xim, XPointer client, XPointer call)
+{
+	xw.ime.xic = NULL;
+	return 1;
+}
+
 void
 xinit(int cols, int rows)
 {
@@ -1132,7 +1146,10 @@ xinit(int cols, int rows)
 	xw.draw = XftDrawCreate(xw.dpy, xw.buf, xw.vis, xw.cmap);
 
 	/* input methods */
-	ximopen(xw.dpy);
+	if (!ximopen(xw.dpy)) {
+		XRegisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
+	                                       ximinstantiate, NULL);
+	}
 
 	/* white cursor, black outline */
 	cursor = XCreateFontCursor(xw.dpy, mouseshape);
@@ -1765,7 +1782,10 @@ kpress(XEvent *ev)
 	if (IS_SET(MODE_KBDLOCK))
 		return;
 
-	len = XmbLookupString(xw.ime.xic, e, buf, sizeof buf, &ksym, &status);
+	if (xw.ime.xic)
+		len = XmbLookupString(xw.ime.xic, e, buf, sizeof buf, &ksym, &status);
+	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)) {

From 51e19ea11dd42eefed1ca136ee3f6be975f618b1 Mon Sep 17 00:00:00 2001
From: Ivan Tham <pickfire@riseup.net>
Date: Tue, 18 Feb 2020 23:28:47 +0800
Subject: [PATCH 06/46] Remove explicit XNFocusWindow

XCreateIC ICValues default XNFocusWindow to XNClientWindow if not
specified, it can be omitted since it is the same.

From the documentation
https://www.x.org/releases/current/doc/libX11/libX11/libX11.html

> Focus Window
>
> The XNFocusWindow argument specifies the focus window. The primary
> purpose of the XNFocusWindow is to identify the window that will receive
> the key event when input is composed.
>
> When this XIC value is left unspecified, the input method will use the
> client window as the default focus window.
---
 x.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/x.c b/x.c
index 1f62129..48a6676 100644
--- a/x.c
+++ b/x.c
@@ -1047,7 +1047,6 @@ ximopen(Display *dpy)
 		xw.ime.xic = XCreateIC(xw.ime.xim, XNInputStyle,
 		                       XIMPreeditNothing | XIMStatusNothing,
 		                       XNClientWindow, xw.win,
-		                       XNFocusWindow, xw.win,
 		                       XNDestroyCallback, &icdestroy,
 		                       NULL);
 	}

From 28ad28839985e965c9ca06a9a202523414c84ac4 Mon Sep 17 00:00:00 2001
From: "Avi Halachmi (:avih)" <avihpit@yahoo.com>
Date: Thu, 2 Apr 2020 11:43:22 +0300
Subject: [PATCH 07/46] mouseshortcuts: fix custom modifier on release

This line didn't work at mshortcuts at config.h:

  /*  mask       button   function  arg       release */
    { ShiftMask, Button2, selpaste, {.i = 0}, 1 },

and now it does work.

The issue was that XButtonEvent.state is "the logical state ... just prior
to the event", which means that on release the state has the Button2Mask
bit set because button2 was down just before it was released.

The issue didn't manifest with the default shift + middle-click on release
(to override mouse mode) because its specified modifier is XK_ANY_MOD, at
which case match(...) ignores any specific bits and simply returns true.

The issue also doesn't manifest on press, because prior to the event
Button<N> was not down and its mask bit is not set.

Fix by filtering out the mask of the button which we're currently matching.

We could have said "well, that's how button events behave, you should
use ShiftMask|Button2Mask for release", but this both not obvious to
figure out, and specifically here always filtering does not prevent
configuring any useful modifiers combination. So it's a win-win.
---
 x.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/x.c b/x.c
index 48a6676..4cf6b21 100644
--- a/x.c
+++ b/x.c
@@ -171,6 +171,7 @@ static void kpress(XEvent *);
 static void cmessage(XEvent *);
 static void resize(XEvent *);
 static void focus(XEvent *);
+static uint buttonmask(uint);
 static int mouseaction(XEvent *, uint);
 static void brelease(XEvent *);
 static void bpress(XEvent *);
@@ -423,16 +424,30 @@ mousereport(XEvent *e)
 	ttywrite(buf, len, 0);
 }
 
+uint
+buttonmask(uint button)
+{
+	return button == Button1 ? Button1Mask
+	     : button == Button2 ? Button2Mask
+	     : button == Button3 ? Button3Mask
+	     : button == Button4 ? Button4Mask
+	     : button == Button5 ? Button5Mask
+	     : 0;
+}
+
 int
 mouseaction(XEvent *e, uint release)
 {
 	MouseShortcut *ms;
 
+	/* ignore Button<N>mask for Button<N> - it's set on release */
+	uint state = e->xbutton.state & ~buttonmask(e->xbutton.button);
+
 	for (ms = mshortcuts; ms < mshortcuts + LEN(mshortcuts); ms++) {
 		if (ms->release == release &&
 		    ms->button == e->xbutton.button &&
-		    (match(ms->mod, e->xbutton.state) ||  /* exact or forced */
-		     match(ms->mod, e->xbutton.state & ~forcemousemod))) {
+		    (match(ms->mod, state) ||  /* exact or forced */
+		     match(ms->mod, state & ~forcemousemod))) {
 			ms->func(&(ms->arg));
 			return 1;
 		}

From 5703aa0390484dd7da4bd9c388c85708d8fcd339 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Fri, 10 Apr 2020 12:12:43 +0200
Subject: [PATCH 08/46] make argv0 not static, fixes a warning with tcc

Reported by Aajonus, thanks!
---
 x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/x.c b/x.c
index 4cf6b21..e5f1737 100644
--- a/x.c
+++ b/x.c
@@ -15,7 +15,7 @@
 #include <X11/Xft/Xft.h>
 #include <X11/XKBlib.h>
 
-static char *argv0;
+char *argv0;
 #include "arg.h"
 #include "st.h"
 #include "win.h"

From 21e0d6e8b8d20903494386e7e6f43201b3761154 Mon Sep 17 00:00:00 2001
From: "Roberto E. Vargas Caballero" <k0ga@shike2.com>
Date: Fri, 10 Apr 2020 22:06:32 +0200
Subject: [PATCH 09/46] Add support for scroll(1)

Scroll is a program that stores all the lines of its child and be used in st as
a way of implementing scrollback.

This solution is much better than implementing the scrollback in st itself
because having a different program allows to use it in any other program
without doing modifications to those programs.
---
 config.def.h |  3 ++-
 st.1         |  3 ++-
 st.c         | 16 ++++++++++------
 st.h         |  1 +
 4 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/config.def.h b/config.def.h
index 546edda..dfcbda9 100644
--- a/config.def.h
+++ b/config.def.h
@@ -11,13 +11,14 @@ static int borderpx = 2;
 /*
  * What program is execed by st depends of these precedence rules:
  * 1: program passed with -e
- * 2: utmp option
+ * 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;
+char *scroll = NULL;
 char *stty_args = "stty raw pass8 nl -echo -iexten -cstopb 38400";
 
 /* identification sequence returned in DA and DECID */
diff --git a/st.1 b/st.1
index e8d6059..39120b4 100644
--- a/st.1
+++ b/st.1
@@ -170,7 +170,8 @@ See the LICENSE file for the terms of redistribution.
 .SH SEE ALSO
 .BR tabbed (1),
 .BR utmp (1),
-.BR stty (1)
+.BR stty (1),
+.BR scroll (1)
 .SH BUGS
 See the TODO file in the distribution.
 
diff --git a/st.c b/st.c
index 3e48410..5f2352a 100644
--- a/st.c
+++ b/st.c
@@ -664,7 +664,7 @@ die(const char *errstr, ...)
 void
 execsh(char *cmd, char **args)
 {
-	char *sh, *prog;
+	char *sh, *prog, *arg;
 	const struct passwd *pw;
 
 	errno = 0;
@@ -678,13 +678,17 @@ execsh(char *cmd, char **args)
 	if ((sh = getenv("SHELL")) == NULL)
 		sh = (pw->pw_shell[0]) ? pw->pw_shell : cmd;
 
-	if (args)
+	if (args) {
 		prog = args[0];
-	else if (utmp)
-		prog = utmp;
-	else
+		arg = NULL;
+	} else if (scroll || utmp) {
+		prog = scroll ? scroll : utmp;
+		arg = scroll ? utmp : NULL;
+	} else {
 		prog = sh;
-	DEFAULT(args, ((char *[]) {prog, NULL}));
+		arg = NULL;
+	}
+	DEFAULT(args, ((char *[]) {prog, arg, NULL}));
 
 	unsetenv("COLUMNS");
 	unsetenv("LINES");
diff --git a/st.h b/st.h
index a1928ca..d978458 100644
--- a/st.h
+++ b/st.h
@@ -113,6 +113,7 @@ char *xstrdup(char *);
 
 /* config.h globals */
 extern char *utmp;
+extern char *scroll;
 extern char *stty_args;
 extern char *vtiden;
 extern wchar_t *worddelimiters;

From e52319cc7d153e4f59b38c4fb4c0556e118d4775 Mon Sep 17 00:00:00 2001
From: "Roberto E. Vargas Caballero" <k0ga@shike2.com>
Date: Fri, 10 Apr 2020 22:25:46 +0200
Subject: [PATCH 10/46] ttyread: test for EOF while reading tty

When a read operation returns 0 then it means that we arrived to the end of the
file, and new reads will return 0 unless you do some other operation such as
lseek(). This case happens with USB-232 adapters when they are unplugged.
---
 st.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/st.c b/st.c
index 5f2352a..81973ee 100644
--- a/st.c
+++ b/st.c
@@ -823,17 +823,24 @@ ttyread(void)
 	int ret;
 
 	/* append read bytes to unprocessed bytes */
-	if ((ret = read(cmdfd, buf+buflen, LEN(buf)-buflen)) < 0)
-		die("couldn't read from shell: %s\n", strerror(errno));
-	buflen += ret;
+	ret = read(cmdfd, buf+buflen, LEN(buf)-buflen);
 
-	written = twrite(buf, buflen, 0);
-	buflen -= written;
-	/* keep any uncomplete utf8 char for the next call */
-	if (buflen > 0)
-		memmove(buf, buf + written, buflen);
+	switch (ret) {
+	case 0:
+		fputs("Found EOF in input\n", stderr);
+		exit(0);
+	case -1:
+		die("couldn't read from shell: %s\n", strerror(errno));
+	default:
+		buflen += ret;
+		written = twrite(buf, buflen, 0);
+		buflen -= written;
+		/* keep any uncomplete utf8 char for the next call */
+		if (buflen > 0)
+			memmove(buf, buf + written, buflen);
+		return ret;
 
-	return ret;
+	}
 }
 
 void

From fbae700a3f32db76106b0ff6f49a73ecf0c2b4fe Mon Sep 17 00:00:00 2001
From: "Roberto E. Vargas Caballero" <k0ga@shike2.com>
Date: Fri, 10 Apr 2020 22:26:12 +0200
Subject: [PATCH 11/46] Fix style issue

---
 st.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/st.c b/st.c
index 81973ee..2ecf8f3 100644
--- a/st.c
+++ b/st.c
@@ -366,7 +366,8 @@ static const char base64_digits[] = {
 char
 base64dec_getc(const char **src)
 {
-	while (**src && !isprint(**src)) (*src)++;
+	while (**src && !isprint(**src))
+		(*src)++;
 	return **src ? *((*src)++) : '=';  /* emulate padding if string ends */
 }
 

From 019449a7e64a881be8cc5d715fe9de32726ba190 Mon Sep 17 00:00:00 2001
From: "Roberto E. Vargas Caballero" <k0ga@shike2.com>
Date: Fri, 10 Apr 2020 22:50:23 +0200
Subject: [PATCH 12/46] Add terminfo entries for backspace mode

St used to use backspace as BS until the commit 230d0c8, but due
to general lack of knowledge of lusers, we moved to the most common
configuration in linux to avoid answering the same question 3 times
per month. With the most common configuration we have a backspace
that returns a DEL, and we have a Delete key that doesn't return a
DEL character neither a BS.

When dealing with devices connected using a serial line (or even
with Plan9) it is more common Backspace as BS and Delete as DEL. For
this reason, st is not always the best tool when you talk with a
serial device.

This patch adds new terminfo entries for Backspace as BS and Delete
as DEL. A patch for confg.h is also added, to make easier switch
between both configurations.
---
 st.info | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/st.info b/st.info
index 78ffd30..1df490b 100644
--- a/st.info
+++ b/st.info
@@ -220,3 +220,13 @@ st-meta-256color| simpleterm with meta key and 256 colors,
 	smm=\E[?1034h,
 	rs2=\E[4l\E>\E[?1034h,
 	is2=\E[4l\E>\E[?1034h,
+
+st-bs| simpleterm with backspace as backspace,
+	use=st,
+	kbs=\010,
+	kdch1=\177,
+
+st-bs-256color| simpleterm with backspace as backspace and 256colors,
+	use=st-256color,
+	kbs=\010,
+	kdch1=\177,

From 0b73612c0dc51dbec1717e5da94bc94559c37246 Mon Sep 17 00:00:00 2001
From: "Roberto E. Vargas Caballero" <k0ga@shike2.com>
Date: Sat, 11 Apr 2020 11:52:58 +0200
Subject: [PATCH 13/46] Update FAQ with the last modifications

---
 FAQ | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/FAQ b/FAQ
index 78c769a..85534a4 100644
--- a/FAQ
+++ b/FAQ
@@ -17,10 +17,16 @@ you can manually run `tic -sx st.info`.
 
 ## How do I scroll back up?
 
-Using a terminal multiplexer.
+* Using a terminal multiplexer.
+	* `st -e tmux` using C-b [
+	* `st -e screen` using C-a ESC
+* Using the excellent tool of [scroll](https://git.suckless.org/scroll/).
+* Using the scrollback [patch](https://st.suckless.org/patches/scrollback/).
 
-* `st -e tmux` using C-b [
-* `st -e screen` using C-a ESC
+## I would like to have utmp and/or scroll functionality by default
+
+You can add the absolute patch of both programs in your config.h
+file. You only have to modify the value of utmp and scroll variables.
 
 ## Why doesn't the Del key work in some programs?
 

From c1145268f6b6c6f03a8bec1c09d356d6a4eba77e Mon Sep 17 00:00:00 2001
From: Quentin Rameau <quinq@fifth.space>
Date: Sat, 11 Apr 2020 12:09:20 +0200
Subject: [PATCH 14/46] Launch scroll program with the default shell

---
 st.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/st.c b/st.c
index 2ecf8f3..59db144 100644
--- a/st.c
+++ b/st.c
@@ -682,9 +682,12 @@ execsh(char *cmd, char **args)
 	if (args) {
 		prog = args[0];
 		arg = NULL;
-	} else if (scroll || utmp) {
-		prog = scroll ? scroll : utmp;
-		arg = scroll ? utmp : NULL;
+	} else if (scroll) {
+		prog = scroll;
+		arg = utmp ? utmp : sh;
+	} else if (utmp) {
+		prog = utmp;
+		arg = NULL;
 	} else {
 		prog = sh;
 		arg = NULL;

From e997303502ddd5c26cfc41af0ff5356bffc04359 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 11 Apr 2020 13:29:48 +0200
Subject: [PATCH 15/46] Fix small typos

---
 st.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/st.c b/st.c
index 59db144..a545724 100644
--- a/st.c
+++ b/st.c
@@ -823,15 +823,14 @@ ttyread(void)
 {
 	static char buf[BUFSIZ];
 	static int buflen = 0;
-	int written;
-	int ret;
+	int ret, written;
 
 	/* append read bytes to unprocessed bytes */
 	ret = read(cmdfd, buf+buflen, LEN(buf)-buflen);
 
 	switch (ret) {
 	case 0:
-		fputs("Found EOF in input\n", stderr);
+		fputs("found EOF in input\n", stderr);
 		exit(0);
 	case -1:
 		die("couldn't read from shell: %s\n", strerror(errno));
@@ -839,7 +838,7 @@ ttyread(void)
 		buflen += ret;
 		written = twrite(buf, buflen, 0);
 		buflen -= written;
-		/* keep any uncomplete utf8 char for the next call */
+		/* keep any incomplete UTF-8 byte sequence for the next call */
 		if (buflen > 0)
 			memmove(buf, buf + written, buflen);
 		return ret;

From d66bd405c0d0f29beff89683a04a10297e962cb9 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 11 Apr 2020 13:56:31 +0200
Subject: [PATCH 16/46] config.def.h: add a comment for the scroll variable

---
 config.def.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/config.def.h b/config.def.h
index dfcbda9..0895a1f 100644
--- a/config.def.h
+++ b/config.def.h
@@ -18,6 +18,7 @@ static int borderpx = 2;
  */
 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";
 

From 771bc401f76b329f78a285ca65355d4b43415172 Mon Sep 17 00:00:00 2001
From: "Roberto E. Vargas Caballero" <k0ga@shike2.com>
Date: Sat, 11 Apr 2020 14:46:17 +0200
Subject: [PATCH 17/46] Add st-mono terminfo entry

This entry is intended for monocolor display and it is very
helpful for color haters.
---
 st.info | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/st.info b/st.info
index 1df490b..e2abc98 100644
--- a/st.info
+++ b/st.info
@@ -1,4 +1,4 @@
-st| simpleterm,
+st-mono| simpleterm monocolor,
 	acsc=+C\,D-A.B0E``aaffgghFiGjjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~,
 	am,
 	bce,
@@ -10,7 +10,7 @@ st| simpleterm,
 	civis=\E[?25l,
 	clear=\E[H\E[2J,
 	cnorm=\E[?12l\E[?25h,
-	colors#8,
+	colors#2,
 	cols#80,
 	cr=^M,
 	csr=\E[%i%p1%d;%p2%dr,
@@ -168,13 +168,8 @@ st| simpleterm,
 	rs1=\Ec,
 	rs2=\E[4l\E>\E[?1034l,
 	sc=\E7,
-	setab=\E[4%p1%dm,
-	setaf=\E[3%p1%dm,
-	setb=\E[4%?%p1%{1}%=%t4%e%p1%{3}%=%t6%e%p1%{4}%=%t1%e%p1%{6}%=%t3%e%p1%d%;m,
-	setf=\E[3%?%p1%{1}%=%t4%e%p1%{3}%=%t6%e%p1%{4}%=%t1%e%p1%{6}%=%t3%e%p1%d%;m,
-	sgr0=\E[0m,
-	sgr=%?%p9%t\E(0%e\E(B%;\E[0%?%p6%t;1%;%?%p2%t;4%;%?%p1%p3%|%t;7%;%?%p4%t;5%;%?%p7%t;8%;m,
 	sitm=\E[3m,
+	sgr0=\E[0m,
 	smacs=\E(0,
 	smcup=\E[?1049h,
 	smir=\E[4h,
@@ -194,6 +189,15 @@ st| simpleterm,
 	Se=\E[2 q,
 	Ss=\E[%p1%d q,
 
+st| simpleterm,
+	use=st-mono,
+	colors#8,
+	setab=\E[4%p1%dm,
+	setaf=\E[3%p1%dm,
+	setb=\E[4%?%p1%{1}%=%t4%e%p1%{3}%=%t6%e%p1%{4}%=%t1%e%p1%{6}%=%t3%e%p1%d%;m,
+	setf=\E[3%?%p1%{1}%=%t4%e%p1%{3}%=%t6%e%p1%{4}%=%t1%e%p1%{6}%=%t3%e%p1%d%;m,
+	sgr=%?%p9%t\E(0%e\E(B%;\E[0%?%p6%t;1%;%?%p2%t;4%;%?%p1%p3%|%t;7%;%?%p4%t;5%;%?%p7%t;8%;m,
+
 st-256color| simpleterm with 256 colors,
 	use=st,
 	ccc,

From 33a9a456644ceb235ea6ce61282f3bdce7a8b547 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 11 Apr 2020 15:45:06 +0200
Subject: [PATCH 18/46] just remove the EOF message

---
 st.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/st.c b/st.c
index a545724..9e568c6 100644
--- a/st.c
+++ b/st.c
@@ -830,7 +830,6 @@ ttyread(void)
 
 	switch (ret) {
 	case 0:
-		fputs("found EOF in input\n", stderr);
 		exit(0);
 	case -1:
 		die("couldn't read from shell: %s\n", strerror(errno));

From 72e3f6c7c05b4d5b56388508bb20a863aec279f5 Mon Sep 17 00:00:00 2001
From: Ivan Tham <pickfire@riseup.net>
Date: Sun, 19 Apr 2020 19:38:39 +0200
Subject: [PATCH 19/46] Update XIM cursor position only if changed

Updating XIM cursor position is expensive, so only update it when cursor
position changed.
---
 st.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/st.c b/st.c
index 9e568c6..0ce6ac2 100644
--- a/st.c
+++ b/st.c
@@ -2571,6 +2571,7 @@ void
 drawregion(int x1, int y1, int x2, int y2)
 {
 	int y;
+
 	for (y = y1; y < y2; y++) {
 		if (!term.dirty[y])
 			continue;
@@ -2583,7 +2584,7 @@ drawregion(int x1, int y1, int x2, int y2)
 void
 draw(void)
 {
-	int cx = term.c.x;
+	int cx = term.c.x, ocx = term.ocx, ocy = term.ocy;
 
 	if (!xstartdraw())
 		return;
@@ -2599,9 +2600,11 @@ 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 = cx, term.ocy = term.c.y;
+	term.ocx = cx;
+	term.ocy = term.c.y;
 	xfinishdraw();
-	xximspot(term.ocx, term.ocy);
+	if (ocx != term.ocx || ocy != term.ocy)
+		xximspot(term.ocx, term.ocy);
 }
 
 void

From 43a395ae91f7d67ce694e65edeaa7bbc720dd027 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Mon, 27 Apr 2020 13:56:25 +0200
Subject: [PATCH 20/46] bump version to 0.8.3

---
 config.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config.mk b/config.mk
index 0cbb002..beafc35 100644
--- a/config.mk
+++ b/config.mk
@@ -1,5 +1,5 @@
 # st version
-VERSION = 0.8.2
+VERSION = 0.8.3
 
 # Customize below to fit your system
 

From d6ea0a1a61853dd892029a7126e7fdb70c371878 Mon Sep 17 00:00:00 2001
From: Jan Klemkow <j.klemkow@wemelug.de>
Date: Thu, 30 Apr 2020 00:10:02 +0200
Subject: [PATCH 21/46] replace exit(3) by _exit(2) in signal handler sigchld()

exit(3) is not async-signal-safe but, _exit(2) is.
This change prevents st to crash and dump core.
---
 st.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/st.c b/st.c
index 0ce6ac2..2bf133f 100644
--- a/st.c
+++ b/st.c
@@ -730,7 +730,7 @@ sigchld(int a)
 		die("child exited with status %d\n", WEXITSTATUS(stat));
 	else if (WIFSIGNALED(stat))
 		die("child terminated due to signal %d\n", WTERMSIG(stat));
-	exit(0);
+	_exit(0);
 }
 
 void

From 1d590910652519268152eae6b97cf30ace4e90c0 Mon Sep 17 00:00:00 2001
From: "Avi Halachmi (:avih)" <avihpit@yahoo.com>
Date: Tue, 26 Feb 2019 22:37:49 +0200
Subject: [PATCH 22/46] auto-sync: draw on idle to avoid flicker/tearing

st could easily tear/flicker with animation or other unattended
output. This commit eliminates most of the tear/flicker.

Before this commit, the display timing had two "modes":

- Interactively, st was waiting fixed `1000/xfps` ms after forwarding
  the kb/mouse event to the application and before drawing.

- Unattended, and specifically with animations, the draw frequency was
  throttled to `actionfps`. Animation at a higher rate would throttle
  and likely tear, and at lower rates it was tearing big frames
  (specifically, when one `read` didn't get a full "frame").

The interactive behavior was decent, but it was impossible to get good
unattended-draw behavior even with carefully chosen configuration.

This commit changes the behavior such that it draws on idle instead of
using fixed latency/frequency. This means that it tries to draw only
when it's very likely that the application has completed its output
(or after some duration without idle), so it mostly succeeds to avoid
tear, flicker, and partial drawing.

The config values minlatency/maxlatency replace xfps/actionfps and
define the range which the algorithm is allowed to wait from the
initial draw-trigger until the actual draw. The range enables the
flexibility to choose when to draw - when least likely to flicker.

It also unifies the interactive and unattended behavior and config
values, which makes the code simpler as well - without sacrificing
latency during interactive use, because typically interactively idle
arrives very quickly, so the wait is typically minlatency.

While it only slighly improves interactive behavior, for animations
and other unattended-drawing it improves greatly, as it effectively
adapts to any [animation] output rate without tearing, throttling,
redundant drawing, or unnecessary delays (sounds impossible, but it
works).
---
 config.def.h |  11 +++--
 x.c          | 120 ++++++++++++++++++++++++---------------------------
 2 files changed, 65 insertions(+), 66 deletions(-)

diff --git a/config.def.h b/config.def.h
index 0895a1f..fdbacfd 100644
--- a/config.def.h
+++ b/config.def.h
@@ -43,9 +43,14 @@ static unsigned int tripleclicktimeout = 600;
 /* alt screens */
 int allowaltscreen = 1;
 
-/* frames per second st should at maximum draw to the screen */
-static unsigned int xfps = 120;
-static unsigned int actionfps = 30;
+/*
+ * 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 = 8;
+static double maxlatency = 33;
 
 /*
  * blinking timeout (set to 0 to disable blinking) for the terminal blinking
diff --git a/x.c b/x.c
index e5f1737..cbbd11f 100644
--- a/x.c
+++ b/x.c
@@ -1867,10 +1867,9 @@ run(void)
 	XEvent ev;
 	int w = win.w, h = win.h;
 	fd_set rfd;
-	int xfd = XConnectionNumber(xw.dpy), xev, blinkset = 0, dodraw = 0;
-	int ttyfd;
-	struct timespec drawtimeout, *tv = NULL, now, last, lastblink;
-	long deltatime;
+	int xfd = XConnectionNumber(xw.dpy), ttyfd, xev, drawing;
+	struct timespec seltv, *tv, now, lastblink, trigger;
+	double timeout;
 
 	/* Waiting for window mapping */
 	do {
@@ -1891,82 +1890,77 @@ run(void)
 	ttyfd = ttynew(opt_line, shell, opt_io, opt_cmd);
 	cresize(w, h);
 
-	clock_gettime(CLOCK_MONOTONIC, &last);
-	lastblink = last;
-
-	for (xev = actionfps;;) {
+	for (timeout = -1, drawing = 0, lastblink = (struct timespec){0};;) {
 		FD_ZERO(&rfd);
 		FD_SET(ttyfd, &rfd);
 		FD_SET(xfd, &rfd);
 
+		if (XPending(xw.dpy))
+			timeout = 0;  /* existing events might not set xfd */
+
+		seltv.tv_sec = timeout / 1E3;
+		seltv.tv_nsec = 1E6 * (timeout - 1E3 * seltv.tv_sec);
+		tv = timeout >= 0 ? &seltv : NULL;
+
 		if (pselect(MAX(xfd, ttyfd)+1, &rfd, NULL, NULL, tv, NULL) < 0) {
 			if (errno == EINTR)
 				continue;
 			die("select failed: %s\n", strerror(errno));
 		}
-		if (FD_ISSET(ttyfd, &rfd)) {
-			ttyread();
-			if (blinktimeout) {
-				blinkset = tattrset(ATTR_BLINK);
-				if (!blinkset)
-					MODBIT(win.mode, 0, MODE_BLINK);
-			}
-		}
+		clock_gettime(CLOCK_MONOTONIC, &now);
 
-		if (FD_ISSET(xfd, &rfd))
-			xev = actionfps;
+		if (FD_ISSET(ttyfd, &rfd))
+			ttyread();
 
-		clock_gettime(CLOCK_MONOTONIC, &now);
-		drawtimeout.tv_sec = 0;
-		drawtimeout.tv_nsec =  (1000 * 1E6)/ xfps;
-		tv = &drawtimeout;
-
-		dodraw = 0;
-		if (blinktimeout && TIMEDIFF(now, lastblink) > blinktimeout) {
-			tsetdirtattr(ATTR_BLINK);
-			win.mode ^= MODE_BLINK;
-			lastblink = now;
-			dodraw = 1;
-		}
-		deltatime = TIMEDIFF(now, last);
-		if (deltatime > 1000 / (xev ? xfps : actionfps)) {
-			dodraw = 1;
-			last = now;
+		xev = 0;
+		while (XPending(xw.dpy)) {
+			xev = 1;
+			XNextEvent(xw.dpy, &ev);
+			if (XFilterEvent(&ev, None))
+				continue;
+			if (handler[ev.type])
+				(handler[ev.type])(&ev);
 		}
 
-		if (dodraw) {
-			while (XPending(xw.dpy)) {
-				XNextEvent(xw.dpy, &ev);
-				if (XFilterEvent(&ev, None))
-					continue;
-				if (handler[ev.type])
-					(handler[ev.type])(&ev);
+		/*
+		 * To reduce flicker and tearing, when new content or event
+		 * triggers drawing, we first wait a bit to ensure we got
+		 * everything, and if nothing new arrives - we draw.
+		 * We start with trying to wait minlatency ms. If more content
+		 * arrives sooner, we retry with shorter and shorter preiods,
+		 * and eventually draw even without idle after maxlatency ms.
+		 * Typically this results in low latency while interacting,
+		 * maximum latency intervals during `cat huge.txt`, and perfect
+		 * sync with periodic updates from animations/key-repeats/etc.
+		 */
+		if (FD_ISSET(ttyfd, &rfd) || xev) {
+			if (!drawing) {
+				trigger = now;
+				drawing = 1;
 			}
+			timeout = (maxlatency - TIMEDIFF(now, trigger)) \
+			          / maxlatency * minlatency;
+			if (timeout > 0)
+				continue;  /* we have time, try to find idle */
+		}
 
-			draw();
-			XFlush(xw.dpy);
-
-			if (xev && !FD_ISSET(xfd, &rfd))
-				xev--;
-			if (!FD_ISSET(ttyfd, &rfd) && !FD_ISSET(xfd, &rfd)) {
-				if (blinkset) {
-					if (TIMEDIFF(now, lastblink) \
-							> blinktimeout) {
-						drawtimeout.tv_nsec = 1000;
-					} else {
-						drawtimeout.tv_nsec = (1E6 * \
-							(blinktimeout - \
-							TIMEDIFF(now,
-								lastblink)));
-					}
-					drawtimeout.tv_sec = \
-					    drawtimeout.tv_nsec / 1E9;
-					drawtimeout.tv_nsec %= (long)1E9;
-				} else {
-					tv = NULL;
-				}
+		/* idle detected or maxlatency exhausted -> draw */
+		timeout = -1;
+		if (blinktimeout && tattrset(ATTR_BLINK)) {
+			timeout = blinktimeout - TIMEDIFF(now, lastblink);
+			if (timeout <= 0) {
+				if (-timeout > blinktimeout) /* start visible */
+					win.mode |= MODE_BLINK;
+				win.mode ^= MODE_BLINK;
+				tsetdirtattr(ATTR_BLINK);
+				lastblink = now;
+				timeout = blinktimeout;
 			}
 		}
+
+		draw();
+		XFlush(xw.dpy);
+		drawing = 0;
 	}
 }
 

From 87545c612e8ab6e7cd1ef38e2355d0cb86df79f2 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 9 May 2020 13:55:34 +0200
Subject: [PATCH 23/46] tiny code-style and typo-fix in comment

---
 st.c | 6 +++---
 x.c  | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/st.c b/st.c
index 2bf133f..c161497 100644
--- a/st.c
+++ b/st.c
@@ -38,7 +38,7 @@
 
 /* macros */
 #define IS_SET(flag)		((term.mode & (flag)) != 0)
-#define ISCONTROLC0(c)		(BETWEEN(c, 0, 0x1f) || (c) == '\177')
+#define ISCONTROLC0(c)		(BETWEEN(c, 0, 0x1f) || (c) == 0x7f)
 #define ISCONTROLC1(c)		(BETWEEN(c, 0x80, 0x9f))
 #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
 #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
@@ -2023,7 +2023,7 @@ tdumpline(int n)
 	bp = &term.line[n][0];
 	end = &bp[MIN(tlinelen(n), term.col) - 1];
 	if (bp != end || bp->u != ' ') {
-		for ( ;bp <= end; ++bp)
+		for ( ; bp <= end; ++bp)
 			tprinter(buf, utf8encode(bp->u, buf));
 	}
 	tprinter("\n", 1);
@@ -2307,7 +2307,7 @@ tputc(Rune u)
 	Glyph *gp;
 
 	control = ISCONTROL(u);
-	if (!IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
+	if (!IS_SET(MODE_UTF8 | MODE_SIXEL)) {
 		c[0] = u;
 		width = len = 1;
 	} else {
diff --git a/x.c b/x.c
index cbbd11f..7bfc36f 100644
--- a/x.c
+++ b/x.c
@@ -1927,7 +1927,7 @@ run(void)
 		 * triggers drawing, we first wait a bit to ensure we got
 		 * everything, and if nothing new arrives - we draw.
 		 * We start with trying to wait minlatency ms. If more content
-		 * arrives sooner, we retry with shorter and shorter preiods,
+		 * arrives sooner, we retry with shorter and shorter periods,
 		 * and eventually draw even without idle after maxlatency ms.
 		 * Typically this results in low latency while interacting,
 		 * maximum latency intervals during `cat huge.txt`, and perfect

From 8211e36d281990a39db1853bcd454ac59e53d521 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 9 May 2020 13:56:28 +0200
Subject: [PATCH 24/46] fix for incorrect (partial) written sequences when libc
 wcwidth() == -1

Fix an issue with incorrect (partial) written sequences when libc wcwidth() ==
-1. The sequence is updated to on wcwidth(u) == -1:

	c = "\357\277\275"

but len isn't.

A way to reproduce in practise:

* st -o dump.txt
* In the terminal: printf '\xcd\xb8'
- This is codepoint 888, on OpenBSD it reports wcwidth() == -1.
- Quit the terminal.
- Look in dump.txt (partial written sequence of "UTF_INVALID").

This was introduced in:

"	commit 11625c7166b7e4dad414606227acec2de1c36464
	Author: czarkoff@gmail.com <czarkoff@gmail.com>
	Date:   Tue Oct 28 12:55:28 2014 +0100

	    Replace character with U+FFFD if wcwidth() is -1

	    Helpful when new Unicode codepoints are not recognized by libc."

Change:

Remove setting the sequence. If this happens to break something, another
solution could be setting len = 3 for the sequence.
---
 st.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/st.c b/st.c
index c161497..5d4054f 100644
--- a/st.c
+++ b/st.c
@@ -2312,10 +2312,8 @@ tputc(Rune u)
 		width = len = 1;
 	} else {
 		len = utf8encode(u, c);
-		if (!control && (width = wcwidth(u)) == -1) {
-			memcpy(c, "\357\277\275", 4); /* UTF_INVALID */
+		if (!control && (width = wcwidth(u)) == -1)
 			width = 1;
-		}
 	}
 
 	if (IS_SET(MODE_PRINT))

From cde480c6939e62771ba3b60ef4eb848031aee9f9 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 9 May 2020 14:03:14 +0200
Subject: [PATCH 25/46] optimize column width calculation and utf-8 encode for
 ASCII

In particular on OpenBSD and on glibc wcwidth() is quite expensive.
On musl there is little difference.
---
 st.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/st.c b/st.c
index 5d4054f..1414f98 100644
--- a/st.c
+++ b/st.c
@@ -2307,7 +2307,7 @@ tputc(Rune u)
 	Glyph *gp;
 
 	control = ISCONTROL(u);
-	if (!IS_SET(MODE_UTF8 | MODE_SIXEL)) {
+	if (u < 127 || !IS_SET(MODE_UTF8 | MODE_SIXEL)) {
 		c[0] = u;
 		width = len = 1;
 	} else {

From 914fb825df3bde7abdd7947e54f8bf4d2b55e34e Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 9 May 2020 14:43:31 +0200
Subject: [PATCH 26/46] code-style: add fallthrough comment

Patch by Steve Ward, thanks.
---
 st.c | 1 +
 x.c  | 1 +
 2 files changed, 2 insertions(+)

diff --git a/st.c b/st.c
index 1414f98..a8de17d 100644
--- a/st.c
+++ b/st.c
@@ -2153,6 +2153,7 @@ tcontrolcode(uchar ascii)
 		return;
 	case '\032': /* SUB */
 		tsetchar('?', &term.c.attr, term.c.x, term.c.y);
+		/* FALLTHROUGH */
 	case '\030': /* CAN */
 		csireset();
 		break;
diff --git a/x.c b/x.c
index 7bfc36f..1dc44d6 100644
--- a/x.c
+++ b/x.c
@@ -1528,6 +1528,7 @@ xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
 		switch (win.cursor) {
 		case 7: /* st extension: snowman (U+2603) */
 			g.u = 0x2603;
+			/* FALLTHROUGH */
 		case 0: /* Blinking Block */
 		case 1: /* Blinking Block (Default) */
 		case 2: /* Steady Block */

From 8304d4f0599b1be2226c28c553547070658d4af3 Mon Sep 17 00:00:00 2001
From: Jakub Leszczak <szatan@gecc.xyz>
Date: Wed, 6 May 2020 13:35:06 +0200
Subject: [PATCH 27/46] Fix selection: selclear in tputc

---
 st.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/st.c b/st.c
index a8de17d..8c42a9c 100644
--- a/st.c
+++ b/st.c
@@ -2412,7 +2412,7 @@ check_control_code:
 		 */
 		return;
 	}
-	if (sel.ob.x != -1 && BETWEEN(term.c.y, sel.ob.y, sel.oe.y))
+	if (selected(term.c.x, term.c.y))
 		selclear();
 
 	gp = &term.line[term.c.y][term.c.x];

From 9c30066e73f0105c3fccb7582c8172d5117857b3 Mon Sep 17 00:00:00 2001
From: Jakub Leszczak <szatan@gecc.xyz>
Date: Wed, 6 May 2020 13:35:53 +0200
Subject: [PATCH 28/46] Fix selection: ignore ATTR_WRAP when rectangular
 selection in getsel

---
 st.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/st.c b/st.c
index 8c42a9c..7c15d5f 100644
--- a/st.c
+++ b/st.c
@@ -634,7 +634,8 @@ getsel(void)
 		 * st.
 		 * FIXME: Fix the computer world.
 		 */
-		if ((y < sel.ne.y || lastx >= linelen) && !(last->mode & ATTR_WRAP))
+		if ((y < sel.ne.y || lastx >= linelen) &&
+		    (!(last->mode & ATTR_WRAP) || sel.type == SEL_RECTANGULAR))
 			*ptr++ = '\n';
 	}
 	*ptr = 0;

From 045a0fab4f80b57f4a982ae6bc5f33fe21d66111 Mon Sep 17 00:00:00 2001
From: Jakub Leszczak <szatan@gecc.xyz>
Date: Wed, 6 May 2020 13:36:59 +0200
Subject: [PATCH 29/46] Fix selection: selscroll

---
 st.c | 26 ++++++++------------------
 1 file changed, 8 insertions(+), 18 deletions(-)

diff --git a/st.c b/st.c
index 7c15d5f..0d35613 100644
--- a/st.c
+++ b/st.c
@@ -1106,27 +1106,17 @@ selscroll(int orig, int n)
 	if (sel.ob.x == -1)
 		return;
 
-	if (BETWEEN(sel.ob.y, orig, term.bot) || BETWEEN(sel.oe.y, orig, term.bot)) {
-		if ((sel.ob.y += n) > term.bot || (sel.oe.y += n) < term.top) {
+	if (BETWEEN(sel.nb.y, orig, term.bot) != BETWEEN(sel.ne.y, orig, term.bot)) {
+		selclear();
+	} else if (BETWEEN(sel.nb.y, orig, term.bot)) {
+		sel.ob.y += n;
+		sel.oe.y += n;
+		if (sel.ob.y < term.top || sel.ob.y > term.bot ||
+		    sel.oe.y < term.top || sel.oe.y > term.bot) {
 			selclear();
-			return;
-		}
-		if (sel.type == SEL_RECTANGULAR) {
-			if (sel.ob.y < term.top)
-				sel.ob.y = term.top;
-			if (sel.oe.y > term.bot)
-				sel.oe.y = term.bot;
 		} else {
-			if (sel.ob.y < term.top) {
-				sel.ob.y = term.top;
-				sel.ob.x = 0;
-			}
-			if (sel.oe.y > term.bot) {
-				sel.oe.y = term.bot;
-				sel.oe.x = term.col;
-			}
+			selnormalize();
 		}
-		selnormalize();
 	}
 }
 

From bda9c9ffa645ee5e4b2507474ebfa1c5efb889b2 Mon Sep 17 00:00:00 2001
From: k0ga <k0ga@shike2.com>
Date: Sat, 16 May 2020 09:48:18 +0000
Subject: [PATCH 30/46] Make shift+wheel behaves as shift+Prev/Next

St uses a very good hack where mouse wheel genereates ^Y and ^E,
that are the same keys that less and vi uses for backward and
fordward scrolling. Scroll, as many terminal emulators, use
shift+Prev/Next for scrolling, but it is also using ^E and ^Y
for scroling, characters that are reserved in the POSIX shell
in emacs mode for end of line and yanking, making scroll unsable
in st.

This patch adds a new hack, making shift+wheel returning the
same sequences than shift+Prev/Next, meaning that scroll or
any other similar program will not be able to differentiate
between them.
---
 config.def.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/config.def.h b/config.def.h
index fdbacfd..293e00c 100644
--- a/config.def.h
+++ b/config.def.h
@@ -171,7 +171,9 @@ static uint forcemousemod = ShiftMask;
 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"} },
 };
 

From f8afebdfa0cc9a57b22c39c47e9b585f69453eb7 Mon Sep 17 00:00:00 2001
From: "Roberto E. Vargas" <k0ga@shike2.com>
Date: Sat, 16 May 2020 10:42:51 +0000
Subject: [PATCH 31/46] Add rin terminfo capability

Tianlin Qu discovered that st is missing rin (scroll back #1 lines).
---
 st.info | 1 +
 1 file changed, 1 insertion(+)

diff --git a/st.info b/st.info
index e2abc98..d0694e2 100644
--- a/st.info
+++ b/st.info
@@ -158,6 +158,7 @@ st-mono| simpleterm monocolor,
 	rc=\E8,
 	rev=\E[7m,
 	ri=\EM,
+	rin=\E[%p1%dT,
 	ritm=\E[23m,
 	rmacs=\E(B,
 	rmcup=\E[?1049l,

From e8392b282c2eaa28725241a9612804fb55113da4 Mon Sep 17 00:00:00 2001
From: "Avi Halachmi (:avih)" <avihpit@yahoo.com>
Date: Thu, 14 May 2020 18:18:07 +0300
Subject: [PATCH 32/46] support REP (repeat) escape sequence

The sequence \e[Nb prints the last printed char N (more) times if it's
printable, and it's ignored after newline or other control chars.

This is Ecma-048/ANSI-X3.6 sequence and not DEC VT. It's supported by
xterm, and ncurses uses it when possible, e.g. when TERM is xterm* (and
with this commit also st*).

xterm supports only codepoints<=255, possibly due to internal limits.
We support any value/codepoint which was placed in a cell.

To test:
- tput rep 65 4 -> prints 'AAAA'
- printf "\342\225\246\033[4b" -> prints U+2566 1+4 times.
---
 st.c    | 10 ++++++++++
 st.info |  1 +
 2 files changed, 11 insertions(+)

diff --git a/st.c b/st.c
index 0d35613..54af098 100644
--- a/st.c
+++ b/st.c
@@ -129,6 +129,7 @@ typedef struct {
 	int charset;  /* current charset */
 	int icharset; /* selected charset for sequence */
 	int *tabs;
+	Rune lastc;   /* last printed char outside of sequence, 0 if control */
 } Term;
 
 /* CSI Escape sequence structs */
@@ -1648,6 +1649,12 @@ csihandle(void)
 		if (csiescseq.arg[0] == 0)
 			ttywrite(vtiden, strlen(vtiden), 0);
 		break;
+	case 'b': /* REP -- if last char is printable print it <n> more times */
+		DEFAULT(csiescseq.arg[0], 1);
+		if (term.lastc)
+			while (csiescseq.arg[0]-- > 0)
+				tputc(term.lastc);
+		break;
 	case 'C': /* CUF -- Cursor <n> Forward */
 	case 'a': /* HPR -- Cursor <n> Forward */
 		DEFAULT(csiescseq.arg[0], 1);
@@ -2373,6 +2380,8 @@ check_control_code:
 		/*
 		 * control codes are not shown ever
 		 */
+		if (!term.esc)
+			term.lastc = 0;
 		return;
 	} else if (term.esc & ESC_START) {
 		if (term.esc & ESC_CSI) {
@@ -2422,6 +2431,7 @@ check_control_code:
 	}
 
 	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
+	term.lastc = u;
 
 	if (width == 2) {
 		gp->mode |= ATTR_WIDE;
diff --git a/st.info b/st.info
index d0694e2..e5393db 100644
--- a/st.info
+++ b/st.info
@@ -184,6 +184,7 @@ st-mono| simpleterm monocolor,
 # XTerm extensions
 	rmxx=\E[29m,
 	smxx=\E[9m,
+	rep=%p1%c\E[%p2%{1}%-%db,
 # tmux extensions, see TERMINFO EXTENSIONS in tmux(1)
 	Tc,
 	Ms=\E]52;%p1%s;%p2%s\007,

From 475a0a36cb4fda1da30f014da65988e99b222876 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 16 May 2020 18:06:42 +0200
Subject: [PATCH 33/46] Revert "support REP (repeat) escape sequence"

This reverts commit e8392b282c2eaa28725241a9612804fb55113da4.

There is currently a bug in older ncurses versions (like on OpenBSD) where a
fix for a bug with REP is not backported yet. Most likely in tty/tty_update.c:

Noticed while using lynx (which uses ncurses/curses).
To reproduce using lynx: echo "Z0000000" | lynx -stdin

or using the program:

int
main(void)
{
	WINDOW *win;
	win = initscr();

	printw("Z0000000");

	refresh();

	sleep(5);

	return 0;
}

This prints "ZZZZZZZ" (incorrectly).
---
 st.c    | 10 ----------
 st.info |  1 -
 2 files changed, 11 deletions(-)

diff --git a/st.c b/st.c
index 54af098..0d35613 100644
--- a/st.c
+++ b/st.c
@@ -129,7 +129,6 @@ typedef struct {
 	int charset;  /* current charset */
 	int icharset; /* selected charset for sequence */
 	int *tabs;
-	Rune lastc;   /* last printed char outside of sequence, 0 if control */
 } Term;
 
 /* CSI Escape sequence structs */
@@ -1649,12 +1648,6 @@ csihandle(void)
 		if (csiescseq.arg[0] == 0)
 			ttywrite(vtiden, strlen(vtiden), 0);
 		break;
-	case 'b': /* REP -- if last char is printable print it <n> more times */
-		DEFAULT(csiescseq.arg[0], 1);
-		if (term.lastc)
-			while (csiescseq.arg[0]-- > 0)
-				tputc(term.lastc);
-		break;
 	case 'C': /* CUF -- Cursor <n> Forward */
 	case 'a': /* HPR -- Cursor <n> Forward */
 		DEFAULT(csiescseq.arg[0], 1);
@@ -2380,8 +2373,6 @@ check_control_code:
 		/*
 		 * control codes are not shown ever
 		 */
-		if (!term.esc)
-			term.lastc = 0;
 		return;
 	} else if (term.esc & ESC_START) {
 		if (term.esc & ESC_CSI) {
@@ -2431,7 +2422,6 @@ check_control_code:
 	}
 
 	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
-	term.lastc = u;
 
 	if (width == 2) {
 		gp->mode |= ATTR_WIDE;
diff --git a/st.info b/st.info
index e5393db..d0694e2 100644
--- a/st.info
+++ b/st.info
@@ -184,7 +184,6 @@ st-mono| simpleterm monocolor,
 # XTerm extensions
 	rmxx=\E[29m,
 	smxx=\E[9m,
-	rep=%p1%c\E[%p2%{1}%-%db,
 # tmux extensions, see TERMINFO EXTENSIONS in tmux(1)
 	Tc,
 	Ms=\E]52;%p1%s;%p2%s\007,

From dec6b530a4fddf405c1822b2cac6e2036d3c8b75 Mon Sep 17 00:00:00 2001
From: Steve Ward <planet36@gmail.com>
Date: Wed, 20 May 2020 22:24:55 -0400
Subject: [PATCH 34/46] Call xsetcursor to set win.cursor in main

In xsetcursor, remove "DEFAULT(cursor, 1)" because 0 is a valid value.
Increase max allowed value of cursor from 6 to 7 (st extension).
---
 x.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/x.c b/x.c
index 1dc44d6..210f184 100644
--- a/x.c
+++ b/x.c
@@ -1526,8 +1526,8 @@ xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
 	/* draw the new one */
 	if (IS_SET(MODE_FOCUSED)) {
 		switch (win.cursor) {
-		case 7: /* st extension: snowman (U+2603) */
-			g.u = 0x2603;
+		case 7: /* st extension */
+			g.u = 0x2603; /* snowman (U+2603) */
 			/* FALLTHROUGH */
 		case 0: /* Blinking Block */
 		case 1: /* Blinking Block (Default) */
@@ -1690,8 +1690,7 @@ xsetmode(int set, unsigned int flags)
 int
 xsetcursor(int cursor)
 {
-	DEFAULT(cursor, 1);
-	if (!BETWEEN(cursor, 0, 6))
+	if (!BETWEEN(cursor, 0, 7)) /* 7: st extension */
 		return 1;
 	win.cursor = cursor;
 	return 0;
@@ -1983,7 +1982,7 @@ main(int argc, char *argv[])
 {
 	xw.l = xw.t = 0;
 	xw.isfixed = False;
-	win.cursor = cursorshape;
+	xsetcursor(cursorshape);
 
 	ARGBEGIN {
 	case 'a':

From 94b8ec002101a5e8f52a342e53431eea71aa0631 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 30 May 2020 21:34:57 +0200
Subject: [PATCH 35/46] Partially add back in "support REP (repeat) escape
 sequence"

Add the functionality back in for xterm compatibility, but do not expose the
capability in st.info (yet).

Some notes:

It was reverted because it caused some issues with ncurses in some
configurations, namely when using BSD padding (--enable-bsdpad, BSD_TPUTS) in
ncurses it caused issues with repeating digits.

A fix has been upstreamed in ncurses since snapshot 20200523. The fix is also
backported to OpenBSD -current.
---
 st.c    | 10 ++++++++++
 st.info |  2 ++
 2 files changed, 12 insertions(+)

diff --git a/st.c b/st.c
index 0d35613..54af098 100644
--- a/st.c
+++ b/st.c
@@ -129,6 +129,7 @@ typedef struct {
 	int charset;  /* current charset */
 	int icharset; /* selected charset for sequence */
 	int *tabs;
+	Rune lastc;   /* last printed char outside of sequence, 0 if control */
 } Term;
 
 /* CSI Escape sequence structs */
@@ -1648,6 +1649,12 @@ csihandle(void)
 		if (csiescseq.arg[0] == 0)
 			ttywrite(vtiden, strlen(vtiden), 0);
 		break;
+	case 'b': /* REP -- if last char is printable print it <n> more times */
+		DEFAULT(csiescseq.arg[0], 1);
+		if (term.lastc)
+			while (csiescseq.arg[0]-- > 0)
+				tputc(term.lastc);
+		break;
 	case 'C': /* CUF -- Cursor <n> Forward */
 	case 'a': /* HPR -- Cursor <n> Forward */
 		DEFAULT(csiescseq.arg[0], 1);
@@ -2373,6 +2380,8 @@ check_control_code:
 		/*
 		 * control codes are not shown ever
 		 */
+		if (!term.esc)
+			term.lastc = 0;
 		return;
 	} else if (term.esc & ESC_START) {
 		if (term.esc & ESC_CSI) {
@@ -2422,6 +2431,7 @@ check_control_code:
 	}
 
 	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
+	term.lastc = u;
 
 	if (width == 2) {
 		gp->mode |= ATTR_WIDE;
diff --git a/st.info b/st.info
index d0694e2..8201ad6 100644
--- a/st.info
+++ b/st.info
@@ -184,6 +184,8 @@ st-mono| simpleterm monocolor,
 # XTerm extensions
 	rmxx=\E[29m,
 	smxx=\E[9m,
+# 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)
 	Tc,
 	Ms=\E]52;%p1%s;%p2%s\007,

From e6e2c6199f102f1459b53717050eee27832f4f87 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 30 May 2020 21:39:49 +0200
Subject: [PATCH 36/46] tiny style fix

---
 st.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/st.c b/st.c
index 54af098..2d901ab 100644
--- a/st.c
+++ b/st.c
@@ -843,7 +843,6 @@ ttyread(void)
 		if (buflen > 0)
 			memmove(buf, buf + written, buflen);
 		return ret;
-
 	}
 }
 
@@ -1778,7 +1777,7 @@ csihandle(void)
 		break;
 	case 'n': /* DSR – Device Status Report (cursor position) */
 		if (csiescseq.arg[0] == 6) {
-			len = snprintf(buf, sizeof(buf),"\033[%i;%iR",
+			len = snprintf(buf, sizeof(buf), "\033[%i;%iR",
 					term.c.y+1, term.c.x+1);
 			ttywrite(buf, len, 0);
 		}

From 0f8b40652bca0670f1f0bda069bbc55f8b5e364d Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 30 May 2020 21:50:54 +0200
Subject: [PATCH 37/46] FAQ: add some details about the w3m img hack

... and an example patch to switch from double-buffering to a single buffer.
---
 FAQ | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 54 insertions(+), 5 deletions(-)

diff --git a/FAQ b/FAQ
index 85534a4..fb40264 100644
--- a/FAQ
+++ b/FAQ
@@ -2,12 +2,14 @@
 
 Use the excellent tool of [utmp](https://git.suckless.org/utmp/) for this task.
 
+
 ## Some _random program_ complains that st is unknown/not recognised/unsupported/whatever!
 
 It means that st doesn’t have any terminfo entry on your system. Chances are
 you did not `make install`. If you just want to test it without installing it,
 you can manually run `tic -sx st.info`.
 
+
 ## Nothing works, and nothing is said about an unknown terminal!
 
 * Some programs just assume they’re running in xterm i.e. they don’t rely on
@@ -15,6 +17,7 @@ you can manually run `tic -sx st.info`.
 * Some programs don’t complain about the lacking st description and default to
   another terminal. In that case see the question about terminfo.
 
+
 ## How do I scroll back up?
 
 * Using a terminal multiplexer.
@@ -23,11 +26,13 @@ you can manually run `tic -sx st.info`.
 * Using the excellent tool of [scroll](https://git.suckless.org/scroll/).
 * Using the scrollback [patch](https://st.suckless.org/patches/scrollback/).
 
+
 ## I would like to have utmp and/or scroll functionality by default
 
 You can add the absolute patch of both programs in your config.h
 file. You only have to modify the value of utmp and scroll variables.
 
+
 ## Why doesn't the Del key work in some programs?
 
 Taken from the terminfo manpage:
@@ -83,12 +88,14 @@ If you are using zsh, then read the zsh FAQ
 
 Putting these lines into your .zshrc will fix the problems.
 
+
 ## How can I use meta in 8bit mode?
 
 St supports meta in 8bit mode, but the default terminfo entry doesn't
 use this capability. If you want it, you have to use the 'st-meta' value
 in TERM.
 
+
 ## I cannot compile st in OpenBSD
 
 OpenBSD lacks librt, despite it being mandatory in POSIX
@@ -97,6 +104,7 @@ If you want to compile st for OpenBSD you have to remove -lrt from config.mk, an
 st will compile without any loss of functionality, because all the functions are
 included in libc on this platform.
 
+
 ## The Backspace Case
 
 St is emulating the Linux way of handling backspace being delete and delete being
@@ -158,19 +166,60 @@ terminal users wants its backspace to be how he feels it:
 	[1] http://www.ibb.net/~anne/keyboard.html
 	[2] http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO-5.html
 
+
 ## But I really want the old grumpy behaviour of my terminal
 
 Apply [1].
 
 [1] https://st.suckless.org/patches/delkey
 
-## Why do images not work in st (in programs such as w3m)?
 
-This is a terrible hack that overdraws an image on top of the terminal emulator
-window. It also relies on a very specific way the terminal draws it's contents.
+## Why do images not work in st using the w3m image hack?
+
+w3mimg uses a hack that draws an image on top of the terminal emulator Drawable
+window. The hack relies on the terminal to use a single buffer to draw its
+contents directly.
+
+st uses double-buffered drawing so the image is quickly replaced and may show a
+short flicker effect.
+
+Below is a patch example to change st double-buffering to a single Drawable
+buffer.
+
+diff --git a/x.c b/x.c
+--- a/x.c
++++ b/x.c
+@@ -561,10 +561,6 @@ xresize(int col, int row)
+ 	win.tw = MAX(1, col * win.cw);
+ 	win.th = MAX(1, row * win.ch);
+ 
+-	XFreePixmap(xw.dpy, xw.buf);
+-	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
+-			DefaultDepth(xw.dpy, xw.scr));
+-	XftDrawChange(xw.draw, xw.buf);
+ 	xclear(0, 0, win.w, win.h);
+ }
+ 
+@@ -921,8 +917,7 @@ xinit(void)
+ 	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 = xw.win;
+ 	XSetForeground(xw.dpy, dc.gc, dc.col[defaultbg].pixel);
+ 	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
+ 
+@@ -1386,8 +1381,6 @@ void
+ draw(void)
+ {
+ 	drawregion(0, 0, term.col, term.row);
+-	XCopyArea(xw.dpy, xw.buf, xw.win, dc.gc, 0, 0, win.w,
+-			win.h, 0, 0);
+ 	XSetForeground(xw.dpy, dc.gc,
+ 			dc.col[IS_SET(MODE_REVERSE)?
+ 				defaultfg : defaultbg].pixel);
 
-A more proper (but limited way) would be using sixels. Which st doesn't
-support.
 
 ## BadLength X error in Xft when trying to render emoji
 

From a2a704492b9f4d2408d180f7aeeacf4c789a1d67 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sat, 30 May 2020 21:56:18 +0200
Subject: [PATCH 38/46] config.def.h: add an option allowwindowops, by default
 off (secure)

Similar to the xterm AllowWindowOps option, this is an option to allow or
disallow certain (non-interactive) operations that can be insecure or
exploited.

NOTE: xsettitle() is not guarded by this because st does not support printing
the window title. Else this could be exploitable (arbitrary code execution).
Similar problems have been found in the past in other terminal emulators.

The sequence for base64-encoded clipboard copy is now guarded because it allows
a sequence written to the terminal to manipulate the clipboard of the running
user non-interactively, for example:

printf '\x1b]52;0;ZWNobyBoaQ0=\a'
---
 config.def.h | 4 ++++
 st.c         | 2 +-
 st.h         | 1 +
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/config.def.h b/config.def.h
index 293e00c..6f05dce 100644
--- a/config.def.h
+++ b/config.def.h
@@ -43,6 +43,10 @@ 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
diff --git a/st.c b/st.c
index 2d901ab..ef8abd5 100644
--- a/st.c
+++ b/st.c
@@ -1861,7 +1861,7 @@ strhandle(void)
 				xsettitle(strescseq.args[1]);
 			return;
 		case 52:
-			if (narg > 2) {
+			if (narg > 2 && allowwindowops) {
 				dec = base64dec(strescseq.args[2]);
 				if (dec) {
 					xsetsel(dec);
diff --git a/st.h b/st.h
index d978458..3d351b6 100644
--- a/st.h
+++ b/st.h
@@ -118,6 +118,7 @@ extern char *stty_args;
 extern char *vtiden;
 extern wchar_t *worddelimiters;
 extern int allowaltscreen;
+extern int allowwindowops;
 extern char *termname;
 extern unsigned int tabspaces;
 extern unsigned int defaultfg;

From 9ba7ecf7b15ec2986c6142036706aa353b249ef9 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Mon, 1 Jun 2020 14:09:46 +0200
Subject: [PATCH 39/46] FAQ: fix single-buffer patch

rebase against master
---
 FAQ | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/FAQ b/FAQ
index fb40264..0f9609d 100644
--- a/FAQ
+++ b/FAQ
@@ -189,18 +189,18 @@ buffer.
 diff --git a/x.c b/x.c
 --- a/x.c
 +++ b/x.c
-@@ -561,10 +561,6 @@ xresize(int col, int row)
- 	win.tw = MAX(1, col * win.cw);
- 	win.th = MAX(1, row * win.ch);
+@@ -732,10 +732,6 @@ xresize(int col, int row)
+ 	win.tw = col * win.cw;
+ 	win.th = row * win.ch;
  
 -	XFreePixmap(xw.dpy, xw.buf);
 -	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
 -			DefaultDepth(xw.dpy, xw.scr));
 -	XftDrawChange(xw.draw, xw.buf);
  	xclear(0, 0, win.w, win.h);
- }
  
-@@ -921,8 +917,7 @@ xinit(void)
+ 	/* resize to new width */
+@@ -1148,8 +1144,7 @@ xinit(int cols, int rows)
  	gcvalues.graphics_exposures = False;
  	dc.gc = XCreateGC(xw.dpy, parent, GCGraphicsExposures,
  			&gcvalues);
@@ -210,10 +210,10 @@ diff --git a/x.c b/x.c
  	XSetForeground(xw.dpy, dc.gc, dc.col[defaultbg].pixel);
  	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
  
-@@ -1386,8 +1381,6 @@ void
- draw(void)
+@@ -1632,8 +1627,6 @@ xdrawline(Line line, int x1, int y1, int x2)
+ void
+ xfinishdraw(void)
  {
- 	drawregion(0, 0, term.col, term.row);
 -	XCopyArea(xw.dpy, xw.buf, xw.win, dc.gc, 0, 0, win.w,
 -			win.h, 0, 0);
  	XSetForeground(xw.dpy, dc.gc,

From 818ec746f4caae453d09368b101c3e841cf39870 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Wed, 17 Jun 2020 21:35:39 +0200
Subject: [PATCH 40/46] fix unicode glitch in DCS strings, patch by Tim Allen
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Reported on the mailinglist:

"
I discovered recently that if an application running inside st tries to
send a DCS string, subsequent Unicode characters get messed up. For
example, consider the following test-case:

    printf '\303\277\033P\033\\\303\277'

...where:

  - \303\277 is the UTF-8 encoding of U+00FF LATIN SMALL LETTER Y WITH
    DIAERESIS (ÿ).
  - \033P is ESC P, the token that begins a DCS string.
  - \033\\ is ESC \, a token that ends a DCS string.
  - \303\277 is the same ÿ character again.

If I run the above command in a VTE-based terminal, or xterm, or
QTerminal, or pterm (PuTTY), I get the output:

    ÿÿ

...which is to say, the empty DCS string is ignored. However, if I run
that command inside st (as of commit 9ba7ecf), I get:

    ÿÿ

...where those last two characters are \303\277 interpreted as ISO8859-1
characters, instead of UTF-8.

I spent some time tracing through the state machines in st.c, and so far
as I can tell, this is how it works currently:

  - ESC P sets the "ESC_DCS" and "ESC_STR" flags, indicating that
    incoming bytes should be collected into the strescseq buffer, rather
    than being interpreted.
  - ESC \ sets the "ESC_STR_END" flag (when ESC is received), and then
    calls strhandle() (when \ is received) to interpret the collected
    bytes.
  - If the collected bytes begin with 'P' (i.e. if this was a DCS
    string) strhandle() sets the "ESC_DCS" flag again, confusing the
    state machine.

If my understanding is correct, fixing the problem should be as easy as
removing the line that sets ESC_DCS from strhandle():

diff --git a/st.c b/st.c
index ef8abd5..b5b805a 100644
--- a/st.c
+++ b/st.c
@@ -1897,7 +1897,6 @@ strhandle(void)
		xsettitle(strescseq.args[0]);
		return;
	case 'P': /* DCS -- Device Control String */
-		term.mode |= ESC_DCS;
	case '_': /* APC -- Application Program Command */
	case '^': /* PM -- Privacy Message */
		return;

I've tried the above patch and it fixes my problem, but I don't know if
it introduces any others.
"
---
 st.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/st.c b/st.c
index ef8abd5..b5b805a 100644
--- a/st.c
+++ b/st.c
@@ -1897,7 +1897,6 @@ strhandle(void)
 		xsettitle(strescseq.args[0]);
 		return;
 	case 'P': /* DCS -- Device Control String */
-		term.mode |= ESC_DCS;
 	case '_': /* APC -- Application Program Command */
 	case '^': /* PM -- Privacy Message */
 		return;

From f74a9df6e1fc88eebe6d673d888b61fd83cf6fc4 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Wed, 17 Jun 2020 22:05:48 +0200
Subject: [PATCH 41/46] remove sixel stub code

Remove stub code that was used for an experiment of adding sixel code to st
from the commit f7398434.
---
 st.c | 26 +++++---------------------
 1 file changed, 5 insertions(+), 21 deletions(-)

diff --git a/st.c b/st.c
index b5b805a..76b7e0d 100644
--- a/st.c
+++ b/st.c
@@ -51,7 +51,6 @@ enum term_mode {
 	MODE_ECHO        = 1 << 4,
 	MODE_PRINT       = 1 << 5,
 	MODE_UTF8        = 1 << 6,
-	MODE_SIXEL       = 1 << 7,
 };
 
 enum cursor_movement {
@@ -78,12 +77,11 @@ enum charset {
 enum escape_state {
 	ESC_START      = 1,
 	ESC_CSI        = 2,
-	ESC_STR        = 4,  /* OSC, PM, APC */
+	ESC_STR        = 4,  /* DCS, OSC, PM, APC */
 	ESC_ALTCHARSET = 8,
 	ESC_STR_END    = 16, /* a final string was encountered */
 	ESC_TEST       = 32, /* Enter in test mode */
 	ESC_UTF8       = 64,
-	ESC_DCS        =128,
 };
 
 typedef struct {
@@ -2090,12 +2088,9 @@ tdectest(char c)
 void
 tstrsequence(uchar c)
 {
-	strreset();
-
 	switch (c) {
 	case 0x90:   /* DCS -- Device Control String */
 		c = 'P';
-		term.esc |= ESC_DCS;
 		break;
 	case 0x9f:   /* APC -- Application Program Command */
 		c = '_';
@@ -2107,6 +2102,7 @@ tstrsequence(uchar c)
 		c = ']';
 		break;
 	}
+	strreset();
 	strescseq.type = c;
 	term.esc |= ESC_STR;
 }
@@ -2304,7 +2300,7 @@ tputc(Rune u)
 	Glyph *gp;
 
 	control = ISCONTROL(u);
-	if (u < 127 || !IS_SET(MODE_UTF8 | MODE_SIXEL)) {
+	if (u < 127 || !IS_SET(MODE_UTF8)) {
 		c[0] = u;
 		width = len = 1;
 	} else {
@@ -2325,23 +2321,11 @@ tputc(Rune u)
 	if (term.esc & ESC_STR) {
 		if (u == '\a' || u == 030 || u == 032 || u == 033 ||
 		   ISCONTROLC1(u)) {
-			term.esc &= ~(ESC_START|ESC_STR|ESC_DCS);
-			if (IS_SET(MODE_SIXEL)) {
-				/* TODO: render sixel */;
-				term.mode &= ~MODE_SIXEL;
-				return;
-			}
+			term.esc &= ~(ESC_START|ESC_STR);
 			term.esc |= ESC_STR_END;
 			goto check_control_code;
 		}
 
-		if (IS_SET(MODE_SIXEL)) {
-			/* TODO: implement sixel mode */
-			return;
-		}
-		if (term.esc&ESC_DCS && strescseq.len == 0 && u == 'q')
-			term.mode |= MODE_SIXEL;
-
 		if (strescseq.len+len >= strescseq.siz) {
 			/*
 			 * Here is a bug in terminals. If the user never sends
@@ -2453,7 +2437,7 @@ twrite(const char *buf, int buflen, int show_ctrl)
 	int n;
 
 	for (n = 0; n < buflen; n += charsize) {
-		if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
+		if (IS_SET(MODE_UTF8)) {
 			/* process a complete utf8 char */
 			charsize = utf8decode(buf + n, &u, buflen - n);
 			if (charsize == 0)

From 81067c65ea4dd80e8eb34755a4f50a4a8c7df06b Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Wed, 17 Jun 2020 23:44:34 +0200
Subject: [PATCH 42/46] LICENSE: bump years

---
 LICENSE | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/LICENSE b/LICENSE
index c356c39..d80eb47 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 MIT/X Consortium License
 
-© 2014-2018 Hiltjo Posthuma <hiltjo at codemadness dot org>
+© 2014-2020 Hiltjo Posthuma <hiltjo at codemadness dot org>
 © 2018 Devin J. Pohly <djpohly at gmail dot com>
 © 2014-2017 Quentin Rameau <quinq at fifth dot space>
 © 2009-2012 Aurélien APTEL <aurelien dot aptel at gmail dot com>

From b27a383a3acc7decf00e6e889fca265430b5d329 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Wed, 17 Jun 2020 23:47:00 +0200
Subject: [PATCH 43/46] config.mk: use PKG_CONFIG in commented OpenBSD section

---
 config.mk | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/config.mk b/config.mk
index beafc35..7b1c3db 100644
--- a/config.mk
+++ b/config.mk
@@ -28,8 +28,8 @@ STLDFLAGS = $(LIBS) $(LDFLAGS)
 # OpenBSD:
 #CPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
 #LIBS = -L$(X11LIB) -lm -lX11 -lutil -lXft \
-#       `pkg-config --libs fontconfig` \
-#       `pkg-config --libs freetype2`
+#       `$(PKG_CONFIG) --libs fontconfig` \
+#       `$(PKG_CONFIG) --libs freetype2`
 
 # compiler and linker
 # CC = c99

From fa253f077f19b3220c7655b81bd91e52f4367803 Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Fri, 19 Jun 2020 11:27:17 +0200
Subject: [PATCH 44/46] bump version to 0.8.4

---
 config.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config.mk b/config.mk
index 7b1c3db..c070a4a 100644
--- a/config.mk
+++ b/config.mk
@@ -1,5 +1,5 @@
 # st version
-VERSION = 0.8.3
+VERSION = 0.8.4
 
 # Customize below to fit your system
 

From 28b4c822c5c0acec300fdf15c6e3ede9f5e2335d Mon Sep 17 00:00:00 2001
From: John Collis <john.collis@alliedtelesis.co.nz>
Date: Sun, 6 Sep 2020 17:53:41 +1200
Subject: [PATCH 45/46] ST: Add WM_ICON_NAME property support

Also added _NET_WM_ICON_NAME.
---
 st.c  |  9 +++++++++
 win.h |  1 +
 x.c   | 16 +++++++++++++++-
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/st.c b/st.c
index 76b7e0d..ae7fa63 100644
--- a/st.c
+++ b/st.c
@@ -1844,6 +1844,7 @@ strhandle(void)
 {
 	char *p = NULL, *dec;
 	int j, narg, par;
+	static int winname = 0;
 
 	term.esc &= ~(ESC_STR_END|ESC_STR);
 	strparse();
@@ -1853,7 +1854,15 @@ strhandle(void)
 	case ']': /* OSC -- Operating System Command */
 		switch (par) {
 		case 0:
+			if (narg > 1) {
+				xsettitle(strescseq.args[1]);
+				xseticontitle(strescseq.args[1]);
+			}
+			return;
 		case 1:
+			if (narg > 1)
+				xseticontitle(strescseq.args[1]);
+			return;
 		case 2:
 			if (narg > 1)
 				xsettitle(strescseq.args[1]);
diff --git a/win.h b/win.h
index a6ef1b9..e6e4369 100644
--- a/win.h
+++ b/win.h
@@ -30,6 +30,7 @@ void xdrawline(Line, int, int, int);
 void xfinishdraw(void);
 void xloadcols(void);
 int xsetcolorname(int, const char *);
+void xseticontitle(char *);
 void xsettitle(char *);
 int xsetcursor(int);
 void xsetmode(int, unsigned int);
diff --git a/x.c b/x.c
index 210f184..120e495 100644
--- a/x.c
+++ b/x.c
@@ -93,7 +93,7 @@ typedef struct {
 	Window win;
 	Drawable buf;
 	GlyphFontSpec *specbuf; /* font spec buffer used for rendering */
-	Atom xembed, wmdeletewin, netwmname, netwmpid;
+	Atom xembed, wmdeletewin, netwmname, netwmiconname, netwmpid;
 	struct {
 		XIM xim;
 		XIC xic;
@@ -1186,6 +1186,7 @@ xinit(int cols, int rows)
 	xw.xembed = XInternAtom(xw.dpy, "_XEMBED", False);
 	xw.wmdeletewin = XInternAtom(xw.dpy, "WM_DELETE_WINDOW", False);
 	xw.netwmname = XInternAtom(xw.dpy, "_NET_WM_NAME", False);
+	xw.netwmiconname = XInternAtom(xw.dpy, "_NET_WM_ICON_NAME", False);
 	XSetWMProtocols(xw.dpy, xw.win, &xw.wmdeletewin, 1);
 
 	xw.netwmpid = XInternAtom(xw.dpy, "_NET_WM_PID", False);
@@ -1579,6 +1580,19 @@ xsetenv(void)
 	setenv("WINDOWID", buf, 1);
 }
 
+void
+xseticontitle(char *p)
+{
+	XTextProperty prop;
+	DEFAULT(p, opt_title);
+
+	Xutf8TextListToTextProperty(xw.dpy, &p, 1, XUTF8StringStyle,
+			&prop);
+	XSetWMIconName(xw.dpy, xw.win, &prop);
+	XSetTextProperty(xw.dpy, xw.win, &prop, xw.netwmiconname);
+	XFree(prop.value);
+}
+
 void
 xsettitle(char *p)
 {

From 4ef0cbd8b9371f37f7d02ef37b5378b879e6b8bf Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma <hiltjo@codemadness.org>
Date: Sun, 18 Oct 2020 11:18:03 +0200
Subject: [PATCH 46/46] remove unused variable from previous patch

---
 st.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/st.c b/st.c
index ae7fa63..abbbe4b 100644
--- a/st.c
+++ b/st.c
@@ -1844,7 +1844,6 @@ strhandle(void)
 {
 	char *p = NULL, *dec;
 	int j, narg, par;
-	static int winname = 0;
 
 	term.esc &= ~(ESC_STR_END|ESC_STR);
 	strparse();