Add support for CSI b control sequence (repeat last printed character) to

the wscons vt100 emulation. Based on a diff from Crystal Kolipe, modified
to properly handle partial updates, verified to work with udl(4).

4 files changed, 74 insertions, 54 deletions

diff --git a/sys/dev/wscons/wsemul_vt100.c b/sys/dev/wscons/wsemul_vt100.c
index 1c122fe68f8..e2184d512e2 100644
--- a/sys/dev/wscons/wsemul_vt100.c
+++ b/sys/dev/wscons/wsemul_vt100.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: wsemul_vt100.c,v 1.47 2023/08/02 19:20:19 miod Exp $ */
+/* $OpenBSD: wsemul_vt100.c,v 1.48 2024/11/05 08:12:08 miod Exp $ */
 /* $NetBSD: wsemul_vt100.c,v 1.13 2000/04/28 21:56:16 mycroft Exp $ */
 
 /*
@@ -80,14 +80,12 @@ void	wsemul_vt100_init(struct wsemul_vt100_emuldata *,
 	    const struct wsscreen_descr *, void *, int, int, uint32_t);
 int	wsemul_vt100_jump_scroll(struct wsemul_vt100_emuldata *,
 	    const u_char *, u_int, int);
-int	wsemul_vt100_output_normal(struct wsemul_vt100_emuldata *,
-	    struct wsemul_inputstate *, int);
 int	wsemul_vt100_output_c0c1(struct wsemul_vt100_emuldata *,
 	    struct wsemul_inputstate *, int);
 int	wsemul_vt100_nextline(struct wsemul_vt100_emuldata *);
 
 typedef int vt100_handler(struct wsemul_vt100_emuldata *, struct
-	    wsemul_inputstate *);
+	    wsemul_inputstate *, int);
 vt100_handler
 	wsemul_vt100_output_esc,
 	wsemul_vt100_output_csi,
@@ -312,9 +310,11 @@ wsemul_vt100_reset(struct wsemul_vt100_emuldata *edp)
 	edp->instate.inchar = 0;
 	edp->instate.lbound = 0;
 	edp->instate.mbleft = 0;
+	edp->instate.last_output = 0;
 	edp->kstate.inchar = 0;
 	edp->kstate.lbound = 0;
 	edp->kstate.mbleft = 0;
+	edp->kstate.last_output = 0;
 }
 
 /*
@@ -347,22 +347,14 @@ wsemul_vt100_nextline(struct wsemul_vt100_emuldata *edp)
 
 int
 wsemul_vt100_output_normal(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate, int kernel)
+    struct wsemul_inputstate *instate, int kernel, int count)
 {
 	u_int *ct, dc;
 	u_char c;
 	int oldsschartab = edp->sschartab;
+	int m;
 	int rc = 0;
 
-	if ((edp->flags & (VTFL_LASTCHAR | VTFL_DECAWM)) ==
-	    (VTFL_LASTCHAR | VTFL_DECAWM)) {
-		rc = wsemul_vt100_nextline(edp);
-		if (rc != 0)
-			return rc;
-		edp->ccol = 0;
-		edp->flags &= ~VTFL_LASTCHAR;
-	}
-
 #ifdef HAVE_UTF8_SUPPORT
 	if (edp->flags & VTFL_UTF8) {
 		(*edp->emulops->mapchar)(edp->emulcookie, instate->inchar, &dc);
@@ -383,26 +375,41 @@ wsemul_vt100_output_normal(struct wsemul_vt100_emuldata *edp,
 		dc = ct ? ct[c] : c;
 	}
 
-	if ((edp->flags & VTFL_INSERTMODE) && COLS_LEFT) {
-		WSEMULOP(rc, edp, &edp->abortstate, copycols,
-		    COPYCOLS(edp->ccol, edp->ccol + 1, COLS_LEFT));
-		if (rc != 0) {
-			/* undo potential sschartab update */
-			edp->sschartab = oldsschartab;
+	for (m = 0; m < count; m++) {
+		if ((edp->flags & (VTFL_LASTCHAR | VTFL_DECAWM)) ==
+		    (VTFL_LASTCHAR | VTFL_DECAWM)) {
+			rc = wsemul_vt100_nextline(edp);
+			if (rc != 0)
+				return rc;
+			edp->ccol = 0;
+			edp->flags &= ~VTFL_LASTCHAR;
+		}
 
-			return rc;
+		if ((edp->flags & VTFL_INSERTMODE) && COLS_LEFT) {
+			WSEMULOP(rc, edp, &edp->abortstate, copycols,
+			    COPYCOLS(edp->ccol, edp->ccol + 1, COLS_LEFT));
+			if (rc != 0)
+				break;
 		}
-	}
 
 #ifdef HAVE_DOUBLE_WIDTH_HEIGHT
-	WSEMULOP(rc, edp, &edp->abortstate, putchar,
-	    (edp->emulcookie, edp->crow, edp->ccol << edp->dw, dc,
-	     kernel ? edp->kernattr : edp->curattr));
+		WSEMULOP(rc, edp, &edp->abortstate, putchar,
+		    (edp->emulcookie, edp->crow, edp->ccol << edp->dw, dc,
+		     kernel ? edp->kernattr : edp->curattr));
 #else
-	WSEMULOP(rc, edp, &edp->abortstate, putchar,
-	    (edp->emulcookie, edp->crow, edp->ccol, dc,
-	     kernel ? edp->kernattr : edp->curattr));
+		WSEMULOP(rc, edp, &edp->abortstate, putchar,
+		    (edp->emulcookie, edp->crow, edp->ccol, dc,
+		     kernel ? edp->kernattr : edp->curattr));
 #endif
+		if (rc != 0)
+			break;
+
+		if (COLS_LEFT)
+			edp->ccol++;
+		else
+			edp->flags |= VTFL_LASTCHAR;
+	}
+
 	if (rc != 0) {
 		/* undo potential sschartab update */
 		edp->sschartab = oldsschartab;
@@ -410,11 +417,6 @@ wsemul_vt100_output_normal(struct wsemul_vt100_emuldata *edp,
 		return rc;
 	}
 
-	if (COLS_LEFT)
-		edp->ccol++;
-	else
-		edp->flags |= VTFL_LASTCHAR;
-
 	return 0;
 }
 
@@ -503,7 +505,7 @@ wsemul_vt100_output_c0c1(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_esc(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	u_int newstate = VT100_EMUL_STATE_NORMAL;
 	int rc = 0;
@@ -656,7 +658,7 @@ wsemul_vt100_output_esc(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_scs94(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	u_int newstate = VT100_EMUL_STATE_NORMAL;
 
@@ -699,7 +701,7 @@ wsemul_vt100_output_scs94(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_scs94_percent(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	switch (instate->inchar) {
 	case '5': /* DEC supplemental graphic */
@@ -721,7 +723,7 @@ wsemul_vt100_output_scs94_percent(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_scs96(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	u_int newstate = VT100_EMUL_STATE_NORMAL;
 	int nrc;
@@ -781,7 +783,7 @@ setnrc:
 
 int
 wsemul_vt100_output_scs96_percent(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	switch (instate->inchar) {
 	case '6': /* portuguese */
@@ -802,7 +804,7 @@ wsemul_vt100_output_scs96_percent(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_esc_spc(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	switch (instate->inchar) {
 	case 'F': /* 7-bit controls */
@@ -824,7 +826,7 @@ wsemul_vt100_output_esc_spc(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_string(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	if (edp->dcsarg && edp->dcstype && edp->dcspos < DCS_MAXLEN) {
 		if (instate->inchar & ~0xff) {
@@ -841,7 +843,7 @@ wsemul_vt100_output_string(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_string_esc(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	if (instate->inchar == '\\') { /* ST complete */
 		wsemul_vt100_handle_dcs(edp);
@@ -854,7 +856,7 @@ wsemul_vt100_output_string_esc(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_dcs(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	u_int newstate = VT100_EMUL_STATE_DCS;
 
@@ -902,7 +904,7 @@ wsemul_vt100_output_dcs(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_dcs_dollar(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	switch (instate->inchar) {
 	case 'p': /* DECRSTS terminal state restore */
@@ -945,7 +947,7 @@ wsemul_vt100_output_dcs_dollar(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_esc_percent(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	switch (instate->inchar) {
 #ifdef HAVE_UTF8_SUPPORT
@@ -969,7 +971,7 @@ wsemul_vt100_output_esc_percent(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_esc_hash(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	int rc = 0;
 
@@ -1049,7 +1051,7 @@ wsemul_vt100_output_esc_hash(struct wsemul_vt100_emuldata *edp,
 
 int
 wsemul_vt100_output_csi(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	u_int newstate = VT100_EMUL_STATE_CSI;
 	int oargs;
@@ -1082,7 +1084,7 @@ wsemul_vt100_output_csi(struct wsemul_vt100_emuldata *edp,
 		oargs = edp->nargs;
 		if (edp->nargs < VT100_EMUL_NARGS)
 			edp->nargs++;
-		rc = wsemul_vt100_handle_csi(edp, instate);
+		rc = wsemul_vt100_handle_csi(edp, instate, kernel);
 		if (rc != 0) {
 			/* undo nargs progress */
 			edp->nargs = oargs;
@@ -1215,9 +1217,11 @@ wsemul_vt100_output(void *cookie, const u_char *data, u_int count, int kernel)
  		}
 
 		if (edp->state == VT100_EMUL_STATE_NORMAL || kernel) {
-			rc = wsemul_vt100_output_normal(edp, instate, kernel);
+			rc =
+			    wsemul_vt100_output_normal(edp, instate, kernel, 1);
 			if (rc != 0)
 				break;
+			instate->last_output = instate->inchar;
 			processed += prev_count - count;
 			continue;
 		}
@@ -1225,7 +1229,7 @@ wsemul_vt100_output(void *cookie, const u_char *data, u_int count, int kernel)
 		if (edp->state > nitems(vt100_output))
 			panic("wsemul_vt100: invalid state %d", edp->state);
 #endif
-		rc = vt100_output[edp->state - 1](edp, instate);
+		rc = vt100_output[edp->state - 1](edp, instate, kernel);
 		if (rc != 0)
 			break;
 		processed += prev_count - count;
diff --git a/sys/dev/wscons/wsemul_vt100_subr.c b/sys/dev/wscons/wsemul_vt100_subr.c
index 9c04ce36912..32dfebfa553 100644
--- a/sys/dev/wscons/wsemul_vt100_subr.c
+++ b/sys/dev/wscons/wsemul_vt100_subr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: wsemul_vt100_subr.c,v 1.30 2023/02/26 15:09:53 miod Exp $ */
+/* $OpenBSD: wsemul_vt100_subr.c,v 1.31 2024/11/05 08:12:08 miod Exp $ */
 /* $NetBSD: wsemul_vt100_subr.c,v 1.7 2000/04/28 21:56:16 mycroft Exp $ */
 
 /*
@@ -225,7 +225,7 @@ wsemul_vt100_el(struct wsemul_vt100_emuldata *edp, int arg)
  */
 int
 wsemul_vt100_handle_csi(struct wsemul_vt100_emuldata *edp,
-    struct wsemul_inputstate *instate)
+    struct wsemul_inputstate *instate, int kernel)
 {
 	int n, m, help, flags, fgcol, bgcol;
 	uint32_t attr, bkgdattr;
@@ -548,6 +548,16 @@ wsemul_vt100_handle_csi(struct wsemul_vt100_emuldata *edp,
 				break;
 		}
 		break;
+	case 'b': /* REP */
+		/*
+		 * We arbitrarily limit the repeat count to 65535 to avoid
+		 * uninterruptible flooding of the console. This matches
+		 * current xterm behaviour.
+		 */
+		n = min(DEF1_ARG(0), 65535);
+		instate->inchar = instate->last_output;
+		rc = wsemul_vt100_output_normal(edp, instate, kernel, n);
+		break;
 	case 'c': /* DA primary */
 		if (ARG(0) == 0)
 			wsdisplay_emulinput(edp->cbcookie, WSEMUL_VT_ID1,
diff --git a/sys/dev/wscons/wsemul_vt100var.h b/sys/dev/wscons/wsemul_vt100var.h
index 4b7c7a6c716..a3875d7bb9a 100644
--- a/sys/dev/wscons/wsemul_vt100var.h
+++ b/sys/dev/wscons/wsemul_vt100var.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: wsemul_vt100var.h,v 1.13 2023/03/06 17:14:44 miod Exp $ */
+/* $OpenBSD: wsemul_vt100var.h,v 1.14 2024/11/05 08:12:08 miod Exp $ */
 /* $NetBSD: wsemul_vt100var.h,v 1.5 2000/04/28 21:56:17 mycroft Exp $ */
 
 /*
@@ -153,10 +153,13 @@ int	wsemul_vt100_scrolldown(struct wsemul_vt100_emuldata *, int);
 int	wsemul_vt100_ed(struct wsemul_vt100_emuldata *, int);
 int	wsemul_vt100_el(struct wsemul_vt100_emuldata *, int);
 int	wsemul_vt100_handle_csi(struct wsemul_vt100_emuldata *,
-	    struct wsemul_inputstate *);
+	    struct wsemul_inputstate *, int);
 void	wsemul_vt100_handle_dcs(struct wsemul_vt100_emuldata *);
 
 int	wsemul_vt100_translate(void *cookie, kbd_t, keysym_t, const u_char **);
 
 void	vt100_initchartables(struct wsemul_vt100_emuldata *);
 int	vt100_setnrc(struct wsemul_vt100_emuldata *, int);
+
+int	wsemul_vt100_output_normal(struct wsemul_vt100_emuldata *,
+	    struct wsemul_inputstate *, int, int);
diff --git a/sys/dev/wscons/wsemulvar.h b/sys/dev/wscons/wsemulvar.h
index a0a88e727be..a0200db44b5 100644
--- a/sys/dev/wscons/wsemulvar.h
+++ b/sys/dev/wscons/wsemulvar.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: wsemulvar.h,v 1.19 2023/03/06 17:14:44 miod Exp $ */
+/* $OpenBSD: wsemulvar.h,v 1.20 2024/11/05 08:12:08 miod Exp $ */
 /* $NetBSD: wsemulvar.h,v 1.6 1999/01/17 15:46:15 drochner Exp $ */
 
 /*
@@ -81,6 +81,9 @@ struct wsemul_inputstate {
 	uint32_t	inchar;	/* character being reconstructed */
 	uint32_t	lbound;	/* lower bound of above */
 	u_int		mbleft;	/* multibyte bytes left until char complete */
+
+	uint32_t	last_output;	/* last printable character */
+					/* (used by vt100 emul only) */
 };
 
 extern const struct wsemul_ops wsemul_dumb_ops;