add scrollback-reflow patch

3 files changed, 2136 insertions, 300 deletions

diff --git a/patches/st-scrollback-reflow-0.8.5.diff b/patches/st-scrollback-reflow-0.8.5.diff
new file mode 100644
index 0000000..085c828
--- /dev/null
+++ b/patches/st-scrollback-reflow-0.8.5.diff
@@ -0,0 +1,1478 @@
+diff --git a/st.c b/st.c
+index 91e7077..a76d983 100644
+--- a/st.c
++++ b/st.c
+@@ -36,6 +36,7 @@
+ #define STR_BUF_SIZ   ESC_BUF_SIZ
+ #define STR_ARG_SIZ   ESC_ARG_SIZ
+ #define HISTSIZE      2000
++#define RESIZEBUFFER  1000
+ 
+ /* macros */
+ #define IS_SET(flag)		((term.mode & (flag)) != 0)
+@@ -43,9 +44,22 @@
+ #define ISCONTROLC1(c)		(BETWEEN(c, 0x80, 0x9f))
+ #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
+ #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
+-#define TLINE(y)		((y) < term.scr ? term.hist[((y) + term.histi - \
+-				term.scr + HISTSIZE + 1) % HISTSIZE] : \
+-				term.line[(y) - term.scr])
++
++#define TLINE(y) ( \
++	(y) < term.scr ? term.hist[(term.histi + (y) - term.scr + 1 + HISTSIZE) % HISTSIZE] \
++	               : term.line[(y) - term.scr] \
++)
++
++#define TLINEABS(y) ( \
++	(y) < 0 ? term.hist[(term.histi + (y) + 1 + HISTSIZE) % HISTSIZE] : term.line[(y)] \
++)
++
++#define UPDATEWRAPNEXT(alt, col) do { \
++	if ((term.c.state & CURSOR_WRAPNEXT) && term.c.x + term.wrapcwidth[alt] < col) { \
++		term.c.x += term.wrapcwidth[alt]; \
++		term.c.state &= ~CURSOR_WRAPNEXT; \
++	} \
++} while (0);
+ 
+ enum term_mode {
+ 	MODE_WRAP        = 1 << 0,
+@@ -57,6 +71,12 @@ enum term_mode {
+ 	MODE_UTF8        = 1 << 6,
+ };
+ 
++enum scroll_mode {
++	SCROLL_RESIZE = -1,
++	SCROLL_NOSAVEHIST = 0,
++	SCROLL_SAVEHIST = 1
++};
++
+ enum cursor_movement {
+ 	CURSOR_SAVE,
+ 	CURSOR_LOAD
+@@ -118,10 +138,11 @@ typedef struct {
+ 	int row;      /* nb row */
+ 	int col;      /* nb col */
+ 	Line *line;   /* screen */
+-	Line *alt;    /* alternate screen */
+ 	Line hist[HISTSIZE]; /* history buffer */
+-	int histi;    /* history index */
+-	int scr;      /* scroll back */
++	int histi;           /* history index */
++	int histf;           /* nb history available */
++	int scr;             /* scroll back */
++	int wrapcwidth[2];   /* used in updating WRAPNEXT when resizing */
+ 	int *dirty;   /* dirtyness of lines */
+ 	TCursor c;    /* cursor */
+ 	int ocx;      /* old cursor col */
+@@ -179,26 +200,37 @@ static void tprinter(char *, size_t);
+ static void tdumpsel(void);
+ static void tdumpline(int);
+ static void tdump(void);
+-static void tclearregion(int, int, int, int);
++static void tclearregion(int, int, int, int, int);
+ static void tcursor(int);
++static void tclearglyph(Glyph *, int);
++static void tresetcursor(void);
+ static void tdeletechar(int);
+ static void tdeleteline(int);
+ static void tinsertblank(int);
+ static void tinsertblankline(int);
+-static int tlinelen(int);
++static int tlinelen(Line len);
++static int tiswrapped(Line line);
++static char *tgetglyphs(char *, const Glyph *, const Glyph *);
++static size_t tgetline(char *, const Glyph *);
+ static void tmoveto(int, int);
+ static void tmoveato(int, int);
+ static void tnewline(int);
+ static void tputtab(int);
+ static void tputc(Rune);
+ static void treset(void);
+-static void tscrollup(int, int, int);
+-static void tscrolldown(int, int, int);
++static void tscrollup(int, int, int, int);
++static void tscrolldown(int, int);
++static void treflow(int, int);
++static void rscrolldown(int);
++static void tresizedef(int, int);
++static void tresizealt(int, int);
+ static void tsetattr(const int *, int);
+ static void tsetchar(Rune, const Glyph *, int, int);
+ static void tsetdirt(int, int);
+ static void tsetscroll(int, int);
+ static void tswapscreen(void);
++static void tloaddefscreen(int, int);
++static void tloadaltscreen(int, int);
+ static void tsetmode(int, int, const int *, int);
+ static int twrite(const char *, int, int);
+ static void tfulldirt(void);
+@@ -212,7 +244,10 @@ static void tstrsequence(uchar);
+ static void drawregion(int, int, int, int);
+ 
+ static void selnormalize(void);
+-static void selscroll(int, int);
++static void selscroll(int, int, int);
++static void selmove(int);
++static void selremove(void);
++static int regionselected(int, int, int, int);
+ static void selsnap(int *, int *, int);
+ 
+ static size_t utf8decode(const char *, Rune *, size_t);
+@@ -412,17 +447,46 @@ selinit(void)
+ }
+ 
+ int
+-tlinelen(int y)
++tlinelen(Line line)
+ {
+-	int i = term.col;
++	int i = term.col - 1;
++
++	for (; i >= 0 && !(line[i].mode & (ATTR_SET | ATTR_WRAP)); i--);
++	return i + 1;
++}
+ 
+-	if (TLINE(y)[i - 1].mode & ATTR_WRAP)
+-		return i;
++int
++tiswrapped(Line line)
++{
++	int len = tlinelen(line);
+ 
+-	while (i > 0 && TLINE(y)[i - 1].u == ' ')
+-		--i;
++	return len > 0 && (line[len - 1].mode & ATTR_WRAP);
++}
+ 
+-	return i;
++char *
++tgetglyphs(char *buf, const Glyph *gp, const Glyph *lgp)
++{
++	while (gp <= lgp)
++		if (gp->mode & ATTR_WDUMMY) {
++			gp++;
++		} else {
++			buf += utf8encode((gp++)->u, buf);
++		}
++	return buf;
++}
++
++size_t
++tgetline(char *buf, const Glyph *fgp)
++{
++	char *ptr;
++	const Glyph *lgp = &fgp[term.col - 1];
++
++	while (lgp > fgp && !(lgp->mode & (ATTR_SET | ATTR_WRAP)))
++		lgp--;
++	ptr = tgetglyphs(buf, fgp, lgp);
++	if (!(lgp->mode & ATTR_WRAP))
++		*(ptr++) = '\n';
++	return ptr - buf;
+ }
+ 
+ void
+@@ -462,10 +526,11 @@ selextend(int col, int row, int type, int done)
+ 
+ 	sel.oe.x = col;
+ 	sel.oe.y = row;
+-	selnormalize();
+ 	sel.type = type;
++	selnormalize();
+ 
+-	if (oldey != sel.oe.y || oldex != sel.oe.x || oldtype != sel.type || sel.mode == SEL_EMPTY)
++	if (oldey != sel.oe.y || oldex != sel.oe.x ||
++	    oldtype != sel.type || sel.mode == SEL_EMPTY)
+ 		tsetdirt(MIN(sel.nb.y, oldsby), MAX(sel.ne.y, oldsey));
+ 
+ 	sel.mode = done ? SEL_IDLE : SEL_READY;
+@@ -492,36 +557,43 @@ selnormalize(void)
+ 	/* expand selection over line breaks */
+ 	if (sel.type == SEL_RECTANGULAR)
+ 		return;
+-	i = tlinelen(sel.nb.y);
+-	if (i < sel.nb.x)
++
++  i = tlinelen(TLINE(sel.nb.y));
++	if (sel.nb.x > i)
+ 		sel.nb.x = i;
+-	if (tlinelen(sel.ne.y) <= sel.ne.x)
+-		sel.ne.x = term.col - 1;
++  if (sel.ne.x >= tlinelen(TLINE(sel.ne.y)))
++    sel.ne.x = term.col - 1;
+ }
+ 
+ int
+-selected(int x, int y)
++regionselected(int x1, int y1, int x2, int y2)
+ {
+-	if (sel.mode == SEL_EMPTY || sel.ob.x == -1 ||
+-			sel.alt != IS_SET(MODE_ALTSCREEN))
++	if (sel.ob.x == -1 || sel.mode == SEL_EMPTY ||
++	    sel.alt != IS_SET(MODE_ALTSCREEN) || sel.nb.y > y2 || sel.ne.y < y1)
+ 		return 0;
+ 
+-	if (sel.type == SEL_RECTANGULAR)
+-		return BETWEEN(y, sel.nb.y, sel.ne.y)
+-		    && BETWEEN(x, sel.nb.x, sel.ne.x);
++	return (sel.type == SEL_RECTANGULAR) ? sel.nb.x <= x2 && sel.ne.x >= x1
++		: (sel.nb.y != y2 || sel.nb.x <= x2) &&
++		  (sel.ne.y != y1 || sel.ne.x >= x1);
++}
+ 
+-	return BETWEEN(y, sel.nb.y, sel.ne.y)
+-	    && (y != sel.nb.y || x >= sel.nb.x)
+-	    && (y != sel.ne.y || x <= sel.ne.x);
++int
++selected(int x, int y)
++{
++	return regionselected(x, y, x, y);
+ }
+ 
+ void
+ selsnap(int *x, int *y, int direction)
+ {
+ 	int newx, newy, xt, yt;
++	int rtop = 0, rbot = term.row - 1;
+ 	int delim, prevdelim;
+ 	const Glyph *gp, *prevgp;
+ 
++	if (!IS_SET(MODE_ALTSCREEN))
++		rtop += -term.histf + term.scr, rbot += term.scr;
++
+ 	switch (sel.snap) {
+ 	case SNAP_WORD:
+ 		/*
+@@ -536,7 +608,7 @@ selsnap(int *x, int *y, int direction)
+ 			if (!BETWEEN(newx, 0, term.col - 1)) {
+ 				newy += direction;
+ 				newx = (newx + term.col) % term.col;
+-				if (!BETWEEN(newy, 0, term.row - 1))
++				if (!BETWEEN(newy, rtop, rbot))
+ 					break;
+ 
+ 				if (direction > 0)
+@@ -547,13 +619,13 @@ selsnap(int *x, int *y, int direction)
+ 					break;
+ 			}
+ 
+-			if (newx >= tlinelen(newy))
++			if (newx >= tlinelen(TLINE(newy)))
+ 				break;
+ 
+ 			gp = &TLINE(newy)[newx];
+ 			delim = ISDELIM(gp->u);
+-			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
+-					|| (delim && gp->u != prevgp->u)))
++			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim ||
++			    (delim && !(gp->u == ' ' && prevgp->u == ' '))))
+ 				break;
+ 
+ 			*x = newx;
+@@ -570,18 +642,14 @@ selsnap(int *x, int *y, int direction)
+ 		 */
+ 		*x = (direction < 0) ? 0 : term.col - 1;
+ 		if (direction < 0) {
+-			for (; *y > 0; *y += direction) {
+-				if (!(TLINE(*y-1)[term.col-1].mode
+-						& ATTR_WRAP)) {
++			for (; *y > rtop; *y -= 1) {
++				if (!tiswrapped(TLINE(*y-1)))
+ 					break;
+-				}
+ 			}
+ 		} else if (direction > 0) {
+-			for (; *y < term.row-1; *y += direction) {
+-				if (!(TLINE(*y)[term.col-1].mode
+-						& ATTR_WRAP)) {
++			for (; *y < rbot; *y += 1) {
++				if (!tiswrapped(TLINE(*y)))
+ 					break;
+-				}
+ 			}
+ 		}
+ 		break;
+@@ -592,40 +660,34 @@ char *
+ getsel(void)
+ {
+ 	char *str, *ptr;
+-	int y, bufsize, lastx, linelen;
+-	const Glyph *gp, *last;
++	int y, lastx, linelen;
++	const Glyph *gp, *lgp;
+ 
+-	if (sel.ob.x == -1)
++	if (sel.ob.x == -1 || sel.alt != IS_SET(MODE_ALTSCREEN))
+ 		return NULL;
+ 
+-	bufsize = (term.col+1) * (sel.ne.y-sel.nb.y+1) * UTF_SIZ;
+-	ptr = str = xmalloc(bufsize);
++	str = xmalloc((term.col + 1) * (sel.ne.y - sel.nb.y + 1) * UTF_SIZ);
++	ptr = str;
+ 
+ 	/* append every set & selected glyph to the selection */
+ 	for (y = sel.nb.y; y <= sel.ne.y; y++) {
+-		if ((linelen = tlinelen(y)) == 0) {
++		Line line = TLINE(y);
++
++		if ((linelen = tlinelen(line)) == 0) {
+ 			*ptr++ = '\n';
+ 			continue;
+ 		}
+ 
+ 		if (sel.type == SEL_RECTANGULAR) {
+-			gp = &TLINE(y)[sel.nb.x];
++			gp = &line[sel.nb.x];
+ 			lastx = sel.ne.x;
+ 		} else {
+-			gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
++			gp = &line[sel.nb.y == y ? sel.nb.x : 0];
+ 			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
+ 		}
+-		last = &TLINE(y)[MIN(lastx, linelen-1)];
+-		while (last >= gp && last->u == ' ')
+-			--last;
+-
+-		for ( ; gp <= last; ++gp) {
+-			if (gp->mode & ATTR_WDUMMY)
+-				continue;
+-
+-			ptr += utf8encode(gp->u, ptr);
+-		}
++		lgp = &line[MIN(lastx, linelen-1)];
+ 
++		ptr = tgetglyphs(ptr, gp, lgp);
+ 		/*
+ 		 * Copy and pasting of line endings is inconsistent
+ 		 * in the inconsistent terminal and GUI world.
+@@ -636,10 +698,10 @@ getsel(void)
+ 		 * FIXME: Fix the computer world.
+ 		 */
+ 		if ((y < sel.ne.y || lastx >= linelen) &&
+-		    (!(last->mode & ATTR_WRAP) || sel.type == SEL_RECTANGULAR))
++		    (!(lgp->mode & ATTR_WRAP) || sel.type == SEL_RECTANGULAR))
+ 			*ptr++ = '\n';
+ 	}
+-	*ptr = 0;
++	*ptr = '\0';
+ 	return str;
+ }
+ 
+@@ -648,9 +710,15 @@ selclear(void)
+ {
+ 	if (sel.ob.x == -1)
+ 		return;
++	selremove();
++	tsetdirt(sel.nb.y, sel.ne.y);
++}
++
++void
++selremove(void)
++{
+ 	sel.mode = SEL_IDLE;
+ 	sel.ob.x = -1;
+-	tsetdirt(sel.nb.y, sel.ne.y);
+ }
+ 
+ void
+@@ -851,10 +919,8 @@ void
+ ttywrite(const char *s, size_t n, int may_echo)
+ {
+ 	const char *next;
+-	Arg arg = (Arg) { .i = term.scr };
+-
+-	kscrolldown(&arg);
+ 
++	kscrolldown(&((Arg){ .i = term.scr }));
+ 	if (may_echo && IS_SET(MODE_ECHO))
+ 		twrite(s, n, 1);
+ 
+@@ -990,7 +1056,7 @@ tsetdirtattr(int attr)
+ 	for (i = 0; i < term.row-1; i++) {
+ 		for (j = 0; j < term.col-1; j++) {
+ 			if (term.line[i][j].mode & attr) {
+-				tsetdirt(i, i);
++				term.dirty[i] = 1;
+ 				break;
+ 			}
+ 		}
+@@ -1000,7 +1066,8 @@ tsetdirtattr(int attr)
+ void
+ tfulldirt(void)
+ {
+-	tsetdirt(0, term.row-1);
++  for (int i = 0; i < term.row; i++)
++		term.dirty[i] = 1;
+ }
+ 
+ void
+@@ -1017,51 +1084,116 @@ tcursor(int mode)
+ 	}
+ }
+ 
++void
++tresetcursor(void)
++{
++	term.c = (TCursor){ { .mode = ATTR_NULL, .fg = defaultfg, .bg = defaultbg },
++	                    .x = 0, .y = 0, .state = CURSOR_DEFAULT };
++}
++
+ void
+ treset(void)
+ {
+ 	uint i;
++  int x, y;
+ 
+-	term.c = (TCursor){{
+-		.mode = ATTR_NULL,
+-		.fg = defaultfg,
+-		.bg = defaultbg
+-	}, .x = 0, .y = 0, .state = CURSOR_DEFAULT};
++	tresetcursor();
+ 
+ 	memset(term.tabs, 0, term.col * sizeof(*term.tabs));
+ 	for (i = tabspaces; i < term.col; i += tabspaces)
+ 		term.tabs[i] = 1;
+ 	term.top = 0;
++	term.histf = 0;
++	term.scr = 0;
+ 	term.bot = term.row - 1;
+ 	term.mode = MODE_WRAP|MODE_UTF8;
+ 	memset(term.trantbl, CS_USA, sizeof(term.trantbl));
+ 	term.charset = 0;
+ 
++  selremove();
+ 	for (i = 0; i < 2; i++) {
+-		tmoveto(0, 0);
+-		tcursor(CURSOR_SAVE);
+-		tclearregion(0, 0, term.col-1, term.row-1);
++  	tcursor(CURSOR_SAVE); /* reset saved cursor */
++		for (y = 0; y < term.row; y++)
++			for (x = 0; x < term.col; x++)
++				tclearglyph(&term.line[y][x], 0);
+ 		tswapscreen();
+ 	}
++  tfulldirt();
+ }
+ 
+ void
+ tnew(int col, int row)
+ {
+-	term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
+-	tresize(col, row);
+-	treset();
++	int i, j;
++
++	for (i = 0; i < 2; i++) {
++		term.line = xmalloc(row * sizeof(Line));
++		for (j = 0; j < row; j++)
++			term.line[j] = xmalloc(col * sizeof(Glyph));
++		term.col = col, term.row = row;
++		tswapscreen();
++	}
++	term.dirty = xmalloc(row * sizeof(*term.dirty));
++	term.tabs = xmalloc(col * sizeof(*term.tabs));
++	for (i = 0; i < HISTSIZE; i++)
++		term.hist[i] = xmalloc(col * sizeof(Glyph));
++  treset();
+ }
+ 
++/* handle it with care */
+ void
+ tswapscreen(void)
+ {
+-	Line *tmp = term.line;
++	static Line *altline;
++	static int altcol, altrow;
++	Line *tmpline = term.line;
++	int tmpcol = term.col, tmprow = term.row;
+ 
+-	term.line = term.alt;
+-	term.alt = tmp;
++	term.line = altline;
++	term.col = altcol, term.row = altrow;
++	altline = tmpline;
++	altcol = tmpcol, altrow = tmprow;
+ 	term.mode ^= MODE_ALTSCREEN;
+-	tfulldirt();
++}
++
++void
++tloaddefscreen(int clear, int loadcursor)
++{
++	int col, row, alt = IS_SET(MODE_ALTSCREEN);
++
++	if (alt) {
++		if (clear)
++			tclearregion(0, 0, term.col-1, term.row-1, 1);
++		col = term.col, row = term.row;
++		tswapscreen();
++	}
++	if (loadcursor)
++		tcursor(CURSOR_LOAD);
++	if (alt)
++		tresizedef(col, row);
++}
++
++void
++tloadaltscreen(int clear, int savecursor)
++{
++	int col, row, def = !IS_SET(MODE_ALTSCREEN);
++
++	if (savecursor)
++		tcursor(CURSOR_SAVE);
++	if (def) {
++		col = term.col, row = term.row;
++		tswapscreen();
++		term.scr = 0;
++		tresizealt(col, row);
++	}
++	if (clear)
++		tclearregion(0, 0, term.col-1, term.row-1, 1);
++}
++
++int
++tisaltscreen(void)
++{
++	return IS_SET(MODE_ALTSCREEN);
+ }
+ 
+ void
+@@ -1069,17 +1201,22 @@ kscrolldown(const Arg* a)
+ {
+ 	int n = a->i;
+ 
+-	if (n < 0)
+-		n = term.row + n;
++	if (!term.scr || IS_SET(MODE_ALTSCREEN))
++		return;
+ 
+-	if (n > term.scr)
+-		n = term.scr;
++	if (n < 0)
++		n = MAX(term.row / -n, 1);
+ 
+-	if (term.scr > 0) {
++	if (n <= term.scr) {
+ 		term.scr -= n;
+-		selscroll(0, -n);
+-		tfulldirt();
++	} else {
++		n = term.scr;
++		term.scr = 0;
+ 	}
++
++	if (sel.ob.x != -1 && !sel.alt)
++		selmove(-n); /* negate change in term.scr */
++	tfulldirt();
+ }
+ 
+ void
+@@ -1087,92 +1224,118 @@ kscrollup(const Arg* a)
+ {
+ 	int n = a->i;
+ 
++	if (!term.histf || IS_SET(MODE_ALTSCREEN))
++		return;
++
+ 	if (n < 0)
+-		n = term.row + n;
++		n = MAX(term.row / -n, 1);
+ 
+-	if (term.scr <= HISTSIZE-n) {
++	if (term.scr + n <= term.histf) {
+ 		term.scr += n;
+-		selscroll(0, n);
+-		tfulldirt();
++	} else {
++		n = term.histf - term.scr;
++		term.scr = term.histf;
+ 	}
++
++	if (sel.ob.x != -1 && !sel.alt)
++		selmove(n); /* negate change in term.scr */
++	tfulldirt();
+ }
+ 
+ void
+-tscrolldown(int orig, int n, int copyhist)
++tscrolldown(int top, int n)
+ {
+-	int i;
++	int i, bot = term.bot;
+ 	Line temp;
+ 
+-	LIMIT(n, 0, term.bot-orig+1);
+-	if (copyhist) {
+-		term.histi = (term.histi - 1 + HISTSIZE) % HISTSIZE;
+-		temp = term.hist[term.histi];
+-		term.hist[term.histi] = term.line[term.bot];
+-		term.line[term.bot] = temp;
+-	}
+-
++	if (n <= 0)
++		return;
++	n = MIN(n, bot-top+1);
+ 
+-	tsetdirt(orig, term.bot-n);
+-	tclearregion(0, term.bot-n+1, term.col-1, term.bot);
++	tsetdirt(top, bot-n);
++	tclearregion(0, bot-n+1, term.col-1, bot, 1);
+ 
+-	for (i = term.bot; i >= orig+n; i--) {
++	for (i = bot; i >= top+n; i--) {
+ 		temp = term.line[i];
+ 		term.line[i] = term.line[i-n];
+ 		term.line[i-n] = temp;
+ 	}
+ 
+-	if (term.scr == 0)
+-		selscroll(orig, n);
++	if (sel.ob.x != -1 && sel.alt == IS_SET(MODE_ALTSCREEN))
++		selscroll(top, bot, n);
+ }
+ 
+ void
+-tscrollup(int orig, int n, int copyhist)
++tscrollup(int top, int bot, int n, int mode)
+ {
+-	int i;
++	int i, j, s;
++	int alt = IS_SET(MODE_ALTSCREEN);
++	int savehist = !alt && top == 0 && mode != SCROLL_NOSAVEHIST;
+ 	Line temp;
+ 
+-	LIMIT(n, 0, term.bot-orig+1);
+-
+-	if (copyhist) {
+-		term.histi = (term.histi + 1) % HISTSIZE;
+-		temp = term.hist[term.histi];
+-		term.hist[term.histi] = term.line[orig];
+-		term.line[orig] = temp;
++	if (n <= 0)
++		return;
++	n = MIN(n, bot-top+1);
++
++	if (savehist) {
++		for (i = 0; i < n; i++) {
++			term.histi = (term.histi + 1) % HISTSIZE;
++			temp = term.hist[term.histi];
++			for (j = 0; j < term.col; j++)
++				tclearglyph(&temp[j], 1);
++			term.hist[term.histi] = term.line[i];
++			term.line[i] = temp;
++		}
++		term.histf = MIN(term.histf + n, HISTSIZE);
++		s = n;
++		if (term.scr) {
++			j = term.scr;
++			term.scr = MIN(j + n, HISTSIZE);
++			s = j + n - term.scr;
++		}
++		if (mode != SCROLL_RESIZE)
++			tfulldirt();
++	} else {
++		tclearregion(0, top, term.col-1, top+n-1, 1);
++		tsetdirt(top+n, bot);
+ 	}
+ 
+-	if (term.scr > 0 && term.scr < HISTSIZE)
+-		term.scr = MIN(term.scr + n, HISTSIZE-1);
+-
+-	tclearregion(0, orig, term.col-1, orig+n-1);
+-	tsetdirt(orig+n, term.bot);
+-
+-	for (i = orig; i <= term.bot-n; i++) {
++	for (i = top; i <= bot-n; i++) {
+ 		temp = term.line[i];
+ 		term.line[i] = term.line[i+n];
+ 		term.line[i+n] = temp;
+ 	}
+ 
+-	if (term.scr == 0)
+-		selscroll(orig, -n);
++	if (sel.ob.x != -1 && sel.alt == alt) {
++		if (!savehist) {
++			selscroll(top, bot, -n);
++		} else if (s > 0) {
++			selmove(-s);
++			if (-term.scr + sel.nb.y < -term.histf)
++				selremove();
++		}
++	}
+ }
+ 
+ void
+-selscroll(int orig, int n)
++selmove(int n)
+ {
+-	if (sel.ob.x == -1)
+-		return;
++	sel.ob.y += n, sel.nb.y += n;
++	sel.oe.y += n, sel.ne.y += n;
++}
++
++void
++selscroll(int top, int bot, int n)
++{
++	/* turn absolute coordinates into relative */
++	top += term.scr, bot += term.scr;
+ 
+-	if (BETWEEN(sel.nb.y, orig, term.bot) != BETWEEN(sel.ne.y, orig, term.bot)) {
++	if (BETWEEN(sel.nb.y, top, bot) != BETWEEN(sel.ne.y, top, 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) {
++	} else if (BETWEEN(sel.nb.y, top, bot)) {
++		selmove(n);
++		if (sel.nb.y < top || sel.ne.y > bot)
+ 			selclear();
+-		} else {
+-			selnormalize();
+-		}
+ 	}
+ }
+ 
+@@ -1182,7 +1345,7 @@ tnewline(int first_col)
+ 	int y = term.c.y;
+ 
+ 	if (y == term.bot) {
+-		tscrollup(term.top, 1, 1);
++		tscrollup(term.top, term.bot, 1, SCROLL_SAVEHIST);
+ 	} else {
+ 		y++;
+ 	}
+@@ -1272,89 +1435,93 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
+ 	} else if (term.line[y][x].mode & ATTR_WDUMMY) {
+ 		term.line[y][x-1].u = ' ';
+ 		term.line[y][x-1].mode &= ~ATTR_WIDE;
+-	}
++  }
+ 
+ 	term.dirty[y] = 1;
+ 	term.line[y][x] = *attr;
+ 	term.line[y][x].u = u;
++	term.line[y][x].mode |= ATTR_SET;
+ }
+ 
+ void
+-tclearregion(int x1, int y1, int x2, int y2)
++tclearglyph(Glyph *gp, int usecurattr)
+ {
+-	int x, y, temp;
+-	Glyph *gp;
++	if (usecurattr) {
++		gp->fg = term.c.attr.fg;
++		gp->bg = term.c.attr.bg;
++	} else {
++		gp->fg = defaultfg;
++		gp->bg = defaultbg;
++	}
++	gp->mode = ATTR_NULL;
++	gp->u = ' ';
++}
+ 
+-	if (x1 > x2)
+-		temp = x1, x1 = x2, x2 = temp;
+-	if (y1 > y2)
+-		temp = y1, y1 = y2, y2 = temp;
++void
++tclearregion(int x1, int y1, int x2, int y2, int usecurattr)
++{
++	int x, y;
+ 
+-	LIMIT(x1, 0, term.col-1);
+-	LIMIT(x2, 0, term.col-1);
+-	LIMIT(y1, 0, term.row-1);
+-	LIMIT(y2, 0, term.row-1);
++	/* regionselected() takes relative coordinates */
++	if (regionselected(x1+term.scr, y1+term.scr, x2+term.scr, y2+term.scr))
++		selremove();
+ 
+ 	for (y = y1; y <= y2; y++) {
+ 		term.dirty[y] = 1;
+-		for (x = x1; x <= x2; x++) {
+-			gp = &term.line[y][x];
+-			if (selected(x, y))
+-				selclear();
+-			gp->fg = term.c.attr.fg;
+-			gp->bg = term.c.attr.bg;
+-			gp->mode = 0;
+-			gp->u = ' ';
+-		}
++		for (x = x1; x <= x2; x++)
++			tclearglyph(&term.line[y][x], usecurattr);
+ 	}
+ }
+ 
+ void
+ tdeletechar(int n)
+ {
+-	int dst, src, size;
+-	Glyph *line;
+-
+-	LIMIT(n, 0, term.col - term.c.x);
++	int src, dst, size;
++	Line line;
+ 
++	if (n <= 0)
++		return;
+ 	dst = term.c.x;
+-	src = term.c.x + n;
++	src = MIN(term.c.x + n, term.col);
+ 	size = term.col - src;
+-	line = term.line[term.c.y];
+-
+-	memmove(&line[dst], &line[src], size * sizeof(Glyph));
+-	tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
++	if (size > 0) { /* otherwise src would point beyond the array
++	                   https://stackoverflow.com/questions/29844298 */
++		line = term.line[term.c.y];
++		memmove(&line[dst], &line[src], size * sizeof(Glyph));
++	}
++	tclearregion(dst + size, term.c.y, term.col - 1, term.c.y, 1);
+ }
+ 
+ void
+ tinsertblank(int n)
+ {
+-	int dst, src, size;
+-	Glyph *line;
++	int src, dst, size;
++	Line line;
+ 
+-	LIMIT(n, 0, term.col - term.c.x);
+-
+-	dst = term.c.x + n;
++	if (n <= 0)
++		return;
++	dst = MIN(term.c.x + n, term.col);
+ 	src = term.c.x;
+ 	size = term.col - dst;
+-	line = term.line[term.c.y];
+-
+-	memmove(&line[dst], &line[src], size * sizeof(Glyph));
+-	tclearregion(src, term.c.y, dst - 1, term.c.y);
++	if (size > 0) { /* otherwise dst would point beyond the array */
++		line = term.line[term.c.y];
++		memmove(&line[dst], &line[src], size * sizeof(Glyph));
++	}
++	tclearregion(src, term.c.y, dst - 1, term.c.y, 1);
+ }
+ 
+ void
+ tinsertblankline(int n)
+ {
+ 	if (BETWEEN(term.c.y, term.top, term.bot))
+-		tscrolldown(term.c.y, n, 0);
++		tscrolldown(term.c.y, n);
+ }
+ 
+ void
+ tdeleteline(int n)
+ {
+ 	if (BETWEEN(term.c.y, term.top, term.bot))
+-		tscrollup(term.c.y, n, 0);
++		tscrollup(term.c.y, term.bot, n, SCROLL_NOSAVEHIST);
+ }
+ 
+ int32_t
+@@ -1528,7 +1695,7 @@ tsetscroll(int t, int b)
+ void
+ tsetmode(int priv, int set, const int *args, int narg)
+ {
+-	int alt; const int *lim;
++	const int *lim;
+ 
+ 	for (lim = args + narg; args < lim; ++args) {
+ 		if (priv) {
+@@ -1589,25 +1756,18 @@ tsetmode(int priv, int set, const int *args, int narg)
+ 				xsetmode(set, MODE_8BIT);
+ 				break;
+ 			case 1049: /* swap screen & set/restore cursor as xterm */
+-				if (!allowaltscreen)
+-					break;
+-				tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
+-				/* FALLTHROUGH */
+ 			case 47: /* swap screen */
+-			case 1047:
++			case 1047: /* swap screen, clearing alternate screen */
+ 				if (!allowaltscreen)
+ 					break;
+-				alt = IS_SET(MODE_ALTSCREEN);
+-				if (alt) {
+-					tclearregion(0, 0, term.col-1,
+-							term.row-1);
+-				}
+-				if (set ^ alt) /* set is always 1 or 0 */
+-					tswapscreen();
+-				if (*args != 1049)
+-					break;
+-				/* FALLTHROUGH */
++				if (set)
++					tloadaltscreen(*args == 1049, *args == 1049);
++				else
++					tloaddefscreen(*args == 1047, *args == 1049);
++				break;
+ 			case 1048:
++				if (!allowaltscreen)
++          break;
+ 				tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
+ 				break;
+ 			case 2004: /* 2004: bracketed paste mode */
+@@ -1659,7 +1819,7 @@ void
+ csihandle(void)
+ {
+ 	char buf[40];
+-	int len;
++	int n, x;
+ 
+ 	switch (csiescseq.mode[0]) {
+ 	default:
+@@ -1757,20 +1917,30 @@ csihandle(void)
+ 	case 'J': /* ED -- Clear screen */
+ 		switch (csiescseq.arg[0]) {
+ 		case 0: /* below */
+-			tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
++			tclearregion(term.c.x, term.c.y, term.col-1, term.c.y, 1);
+ 			if (term.c.y < term.row-1) {
+-				tclearregion(0, term.c.y+1, term.col-1,
+-						term.row-1);
++				tclearregion(0, term.c.y+1, term.col-1, term.row-1, 1);
+ 			}
+ 			break;
+ 		case 1: /* above */
+-			if (term.c.y > 1)
+-				tclearregion(0, 0, term.col-1, term.c.y-1);
+-			tclearregion(0, term.c.y, term.c.x, term.c.y);
++			if (term.c.y >= 1)
++				tclearregion(0, 0, term.col-1, term.c.y-1, 1);
++			tclearregion(0, term.c.y, term.c.x, term.c.y, 1);
+ 			break;
+ 		case 2: /* all */
+-			tclearregion(0, 0, term.col-1, term.row-1);
+-			break;
++			if (IS_SET(MODE_ALTSCREEN)) {
++  			tclearregion(0, 0, term.col-1, term.row-1, 1);
++  			break;
++      }
++			/* vte does this:
++			tscrollup(0, term.row-1, term.row, SCROLL_SAVEHIST); */
++      
++			/* alacritty does this: */
++			for (n = term.row-1; n >= 0 && tlinelen(term.line[n]) == 0; n--);
++			if (n >= 0)
++				tscrollup(0, term.row-1, n+1, SCROLL_SAVEHIST);
++			tscrollup(0, term.row-1, term.row-n-1, SCROLL_NOSAVEHIST);
++      break;
+ 		default:
+ 			goto unknown;
+ 		}
+@@ -1778,24 +1948,24 @@ csihandle(void)
+ 	case 'K': /* EL -- Clear line */
+ 		switch (csiescseq.arg[0]) {
+ 		case 0: /* right */
+-			tclearregion(term.c.x, term.c.y, term.col-1,
+-					term.c.y);
++			tclearregion(term.c.x, term.c.y, term.col-1, term.c.y, 1);
+ 			break;
+ 		case 1: /* left */
+-			tclearregion(0, term.c.y, term.c.x, term.c.y);
++			tclearregion(0, term.c.y, term.c.x, term.c.y, 1);
+ 			break;
+ 		case 2: /* all */
+-			tclearregion(0, term.c.y, term.col-1, term.c.y);
++			tclearregion(0, term.c.y, term.col-1, term.c.y, 1);
+ 			break;
+ 		}
+ 		break;
+ 	case 'S': /* SU -- Scroll <n> line up */
+ 		DEFAULT(csiescseq.arg[0], 1);
+-		tscrollup(term.top, csiescseq.arg[0], 0);
++		/* xterm, urxvt, alacritty save this in history */
++		tscrollup(term.top, term.bot, csiescseq.arg[0], SCROLL_SAVEHIST);
+ 		break;
+ 	case 'T': /* SD -- Scroll <n> line down */
+ 		DEFAULT(csiescseq.arg[0], 1);
+-		tscrolldown(term.top, csiescseq.arg[0], 0);
++		tscrolldown(term.top, csiescseq.arg[0]);
+ 		break;
+ 	case 'L': /* IL -- Insert <n> blank lines */
+ 		DEFAULT(csiescseq.arg[0], 1);
+@@ -1809,9 +1979,11 @@ csihandle(void)
+ 		tdeleteline(csiescseq.arg[0]);
+ 		break;
+ 	case 'X': /* ECH -- Erase <n> char */
++		if (csiescseq.arg[0] < 0)
++			return;
+ 		DEFAULT(csiescseq.arg[0], 1);
+-		tclearregion(term.c.x, term.c.y,
+-				term.c.x + csiescseq.arg[0] - 1, term.c.y);
++		x = MIN(term.c.x + csiescseq.arg[0], term.col) - 1;
++		tclearregion(term.c.x, term.c.y, x, term.c.y, 1);
+ 		break;
+ 	case 'P': /* DCH -- Delete <n> char */
+ 		DEFAULT(csiescseq.arg[0], 1);
+@@ -1833,9 +2005,9 @@ csihandle(void)
+ 		break;
+ 	case 'n': /* DSR – Device Status Report (cursor position) */
+ 		if (csiescseq.arg[0] == 6) {
+-			len = snprintf(buf, sizeof(buf), "\033[%i;%iR",
++			n = snprintf(buf, sizeof(buf), "\033[%i;%iR",
+ 					term.c.y+1, term.c.x+1);
+-			ttywrite(buf, len, 0);
++			ttywrite(buf, n, 0);
+ 		}
+ 		break;
+ 	case 'r': /* DECSTBM -- Set Scrolling Region */
+@@ -2128,16 +2300,8 @@ tdumpsel(void)
+ void
+ tdumpline(int n)
+ {
+-	char buf[UTF_SIZ];
+-	const Glyph *bp, *end;
+-
+-	bp = &term.line[n][0];
+-	end = &bp[MIN(tlinelen(n), term.col) - 1];
+-	if (bp != end || bp->u != ' ') {
+-		for ( ; bp <= end; ++bp)
+-			tprinter(buf, utf8encode(bp->u, buf));
+-	}
+-	tprinter("\n", 1);
++	char str[(term.col + 1) * UTF_SIZ];
++  tprinter(str, tgetline(str, &term.line[n][0]));
+ }
+ 
+ void
+@@ -2358,7 +2522,7 @@ eschandle(uchar ascii)
+ 		return 0;
+ 	case 'D': /* IND -- Linefeed */
+ 		if (term.c.y == term.bot) {
+-			tscrollup(term.top, 1, 1);
++			tscrollup(term.top, term.bot, 1, SCROLL_SAVEHIST);
+ 		} else {
+ 			tmoveto(term.c.x, term.c.y+1);
+ 		}
+@@ -2371,7 +2535,7 @@ eschandle(uchar ascii)
+ 		break;
+ 	case 'M': /* RI -- Reverse index */
+ 		if (term.c.y == term.top) {
+-			tscrolldown(term.top, 1, 1);
++			tscrolldown(term.top, 1);
+ 		} else {
+ 			tmoveto(term.c.x, term.c.y-1);
+ 		}
+@@ -2511,7 +2675,8 @@ check_control_code:
+ 		 */
+ 		return;
+ 	}
+-	if (selected(term.c.x, term.c.y))
++	/* selected() takes relative coordinates */
++	if (selected(term.c.x + term.scr, term.c.y + term.scr))
+ 		selclear();
+ 
+ 	gp = &term.line[term.c.y][term.c.x];
+@@ -2546,6 +2711,7 @@ check_control_code:
+ 	if (term.c.x+width < term.col) {
+ 		tmoveto(term.c.x+width, term.c.y);
+ 	} else {
++		term.wrapcwidth[IS_SET(MODE_ALTSCREEN)] = width;
+ 		term.c.state |= CURSOR_WRAPNEXT;
+ 	}
+ }
+@@ -2583,93 +2749,275 @@ twrite(const char *buf, int buflen, int show_ctrl)
+ }
+ 
+ void
+-tresize(int col, int row)
++treflow(int col, int row)
+ {
+ 	int i, j;
+-	int minrow = MIN(row, term.row);
+-	int mincol = MIN(col, term.col);
+-	int *bp;
+-	TCursor c;
+-
+-	if (col < 1 || row < 1) {
+-		fprintf(stderr,
+-		        "tresize: error resizing to %dx%d\n", col, row);
+-		return;
++	int oce, nce, bot, scr;
++	int ox = 0, oy = -term.histf, nx = 0, ny = -1, len;
++	int cy = -1; /* proxy for new y coordinate of cursor */
++	int nlines;
++	Line *buf, line;
++
++	/* y coordinate of cursor line end */
++	for (oce = term.c.y; oce < term.row - 1 &&
++	                     tiswrapped(term.line[oce]); oce++);
++
++	nlines = term.histf + oce + 1;
++	if (col < term.col) {
++		/* each line can take this many lines after reflow */
++		j = (term.col + col - 1) / col;
++		nlines = j * nlines;
++		if (nlines > HISTSIZE + RESIZEBUFFER + row) {
++			nlines = HISTSIZE + RESIZEBUFFER + row;
++			oy = -(nlines / j - oce - 1);
++		}
+ 	}
++	buf = xmalloc(nlines * sizeof(Line));
++	do {
++		if (!nx)
++			buf[++ny] = xmalloc(col * sizeof(Glyph));
++		if (!ox) {
++			line = TLINEABS(oy);
++			len = tlinelen(line);
++		}
++		if (oy == term.c.y) {
++			if (!ox)
++				len = MAX(len, term.c.x + 1);
++			/* update cursor */
++			if (cy < 0 && term.c.x - ox < col - nx) {
++				term.c.x = nx + term.c.x - ox, cy = ny;
++				UPDATEWRAPNEXT(0, col);
++			}
++		}
++		/* get reflowed lines in buf */
++		if (col - nx > len - ox) {
++			memcpy(&buf[ny][nx], &line[ox], (len-ox) * sizeof(Glyph));
++			nx += len - ox;
++			if (len == 0 || !(line[len - 1].mode & ATTR_WRAP)) {
++				for (j = nx; j < col; j++)
++					tclearglyph(&buf[ny][j], 0);
++				nx = 0;
++			} else if (nx > 0) {
++				buf[ny][nx - 1].mode &= ~ATTR_WRAP;
++			}
++			ox = 0, oy++;
++		} else if (col - nx == len - ox) {
++			memcpy(&buf[ny][nx], &line[ox], (col-nx) * sizeof(Glyph));
++			ox = 0, oy++, nx = 0;
++		} else/* if (col - nx < len - ox) */ {
++			memcpy(&buf[ny][nx], &line[ox], (col-nx) * sizeof(Glyph));
++    	ox += col - nx;
++			buf[ny][col - 1].mode |= ATTR_WRAP;
++			nx = 0;
++		}
++	} while (oy <= oce);
++	if (nx)
++		for (j = nx; j < col; j++)
++			tclearglyph(&buf[ny][j], 0);
+ 
+-	/*
+-	 * slide screen to keep cursor where we expect it -
+-	 * tscrollup would work here, but we can optimize to
+-	 * memmove because we're freeing the earlier lines
+-	 */
+-	for (i = 0; i <= term.c.y - row; i++) {
++	/* free extra lines */
++	for (i = row; i < term.row; i++)
+ 		free(term.line[i]);
+-		free(term.alt[i]);
++	/* resize to new height */
++	term.line = xrealloc(term.line, row * sizeof(Line));
++
++	bot = MIN(ny, row - 1);
++	scr = MAX(row - term.row, 0);
++	/* update y coordinate of cursor line end */
++	nce = MIN(oce + scr, bot);
++	/* update cursor y coordinate */
++	term.c.y = nce - (ny - cy);
++	if (term.c.y < 0) {
++		j = nce, nce = MIN(nce + -term.c.y, bot);
++		term.c.y += nce - j;
++		while (term.c.y < 0) {
++			free(buf[ny--]);
++			term.c.y++;
++		}
+ 	}
+-	/* ensure that both src and dst are not NULL */
+-	if (i > 0) {
+-		memmove(term.line, term.line + i, row * sizeof(Line));
+-		memmove(term.alt, term.alt + i, row * sizeof(Line));
++	/* allocate new rows */
++	for (i = row - 1; i > nce; i--) {
++		term.line[i] = xmalloc(col * sizeof(Glyph));
++		for (j = 0; j < col; j++)
++			tclearglyph(&term.line[i][j], 0);
+ 	}
+-	for (i += row; i < term.row; i++) {
++	/* fill visible area */
++	for (/*i = nce */; i >= term.row; i--, ny--)
++		term.line[i] = buf[ny];
++	for (/*i = term.row - 1 */; i >= 0; i--, ny--) {
+ 		free(term.line[i]);
+-		free(term.alt[i]);
++		term.line[i] = buf[ny];
++	}
++	/* fill lines in history buffer and update term.histf */
++	for (/*i = -1 */; ny >= 0 && i >= -HISTSIZE; i--, ny--) {
++		j = (term.histi + i + 1 + HISTSIZE) % HISTSIZE;
++		free(term.hist[j]);
++		term.hist[j] = buf[ny];
+ 	}
++	term.histf = -i - 1;
++	term.scr = MIN(term.scr, term.histf);
++	/* resize rest of the history lines */
++	for (/*i = -term.histf - 1 */; i >= -HISTSIZE; i--) {
++		j = (term.histi + i + 1 + HISTSIZE) % HISTSIZE;
++		term.hist[j] = xrealloc(term.hist[j], col * sizeof(Glyph));
++	}
++	free(buf);
++}
+ 
+-	/* resize to new height */
+-	term.line = xrealloc(term.line, row * sizeof(Line));
+-	term.alt  = xrealloc(term.alt,  row * sizeof(Line));
+-	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
+-	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
++void
++rscrolldown(int n)
++{
++	int i;
++	Line temp;
+ 
+-	for (i = 0; i < HISTSIZE; i++) {
+-		term.hist[i] = xrealloc(term.hist[i], col * sizeof(Glyph));
+-		for (j = mincol; j < col; j++) {
+-			term.hist[i][j] = term.c.attr;
+-			term.hist[i][j].u = ' ';
+-		}
+-	}
++	/* can never be true as of now
++	if (IS_SET(MODE_ALTSCREEN))
++		return; */
+ 
+-	/* resize each row to new width, zero-pad if needed */
+-	for (i = 0; i < minrow; i++) {
+-		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
+-		term.alt[i]  = xrealloc(term.alt[i],  col * sizeof(Glyph));
+-	}
++	if ((n = MIN(n, term.histf)) <= 0)
++		return;
+ 
+-	/* allocate any new rows */
+-	for (/* i = minrow */; i < row; i++) {
+-		term.line[i] = xmalloc(col * sizeof(Glyph));
+-		term.alt[i] = xmalloc(col * sizeof(Glyph));
++	for (i = term.c.y + n; i >= n; i--) {
++		temp = term.line[i];
++		term.line[i] = term.line[i-n];
++		term.line[i-n] = temp;
+ 	}
++	for (/*i = n - 1 */; i >= 0; i--) {
++		temp = term.line[i];
++		term.line[i] = term.hist[term.histi];
++		term.hist[term.histi] = temp;
++		term.histi = (term.histi - 1 + HISTSIZE) % HISTSIZE;
++	}
++	term.c.y += n;
++	term.histf -= n;
++	if ((i = term.scr - n) >= 0) {
++		term.scr = i;
++	} else {
++		term.scr = 0;
++		if (sel.ob.x != -1 && !sel.alt)
++			selmove(-i);
++	}
++}
++
++void
++tresize(int col, int row)
++{
++	int *bp;
++
++	/* col and row are always MAX(_, 1)
++	if (col < 1 || row < 1) {
++		fprintf(stderr, "tresize: error resizing to %dx%d\n", col, row);
++		return;
++	} */
++
++	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
++	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
+ 	if (col > term.col) {
+ 		bp = term.tabs + term.col;
+-
+ 		memset(bp, 0, sizeof(*term.tabs) * (col - term.col));
+ 		while (--bp > term.tabs && !*bp)
+ 			/* nothing */ ;
+ 		for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
+ 			*bp = 1;
+ 	}
+-	/* update terminal size */
+-	term.col = col;
+-	term.row = row;
+-	/* reset scrolling region */
+-	tsetscroll(0, row-1);
+-	/* make use of the LIMIT in tmoveto */
+-	tmoveto(term.c.x, term.c.y);
+-	/* Clearing both screens (it makes dirty all lines) */
+-	c = term.c;
+-	for (i = 0; i < 2; i++) {
+-		if (mincol < col && 0 < minrow) {
+-			tclearregion(mincol, 0, col - 1, minrow - 1);
++
++	if (IS_SET(MODE_ALTSCREEN))
++		tresizealt(col, row);
++	else
++		tresizedef(col, row);
++}
++
++void
++tresizedef(int col, int row)
++{
++	int i, j;
++
++	/* return if dimensions haven't changed */
++	if (term.col == col && term.row == row) {
++		tfulldirt();
++		return;
++	}
++	if (col != term.col) {
++		if (!sel.alt)
++			selremove();
++		treflow(col, row);
++	} else {
++		/* slide screen up if otherwise cursor would get out of the screen */
++		if (term.c.y >= row) {
++			tscrollup(0, term.row - 1, term.c.y - row + 1, SCROLL_RESIZE);
++			term.c.y = row - 1;
+ 		}
+-		if (0 < col && minrow < row) {
+-			tclearregion(0, minrow, col - 1, row - 1);
++		for (i = row; i < term.row; i++)
++			free(term.line[i]);
++
++		/* resize to new height */
++		term.line = xrealloc(term.line, row * sizeof(Line));
++		/* allocate any new rows */
++		for (i = term.row; i < row; i++) {
++			term.line[i] = xmalloc(col * sizeof(Glyph));
++			for (j = 0; j < col; j++)
++				tclearglyph(&term.line[i][j], 0);
+ 		}
+-		tswapscreen();
+-		tcursor(CURSOR_LOAD);
++		/* scroll down as much as height has increased */
++		rscrolldown(row - term.row);
++	}
++	/* update terminal size */
++	term.col = col, term.row = row;
++	/* reset scrolling region */
++	term.top = 0, term.bot = row - 1;
++	/* dirty all lines */
++	tfulldirt();
++}
++
++void
++tresizealt(int col, int row)
++{
++	int i, j;
++
++	/* return if dimensions haven't changed */
++	if (term.col == col && term.row == row) {
++		tfulldirt();
++		return;
+ 	}
+-	term.c = c;
++	if (sel.alt)
++		selremove();
++	/* slide screen up if otherwise cursor would get out of the screen */
++	for (i = 0; i <= term.c.y - row; i++)
++		free(term.line[i]);
++	if (i > 0) {
++		/* ensure that both src and dst are not NULL */
++		memmove(term.line, term.line + i, row * sizeof(Line));
++		term.c.y = row - 1;
++	}
++	for (i += row; i < term.row; i++)
++		free(term.line[i]);
++	/* resize to new height */
++	term.line = xrealloc(term.line, row * sizeof(Line));
++	/* resize to new width */
++	for (i = 0; i < MIN(row, term.row); i++) {
++		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
++		for (j = term.col; j < col; j++)
++			tclearglyph(&term.line[i][j], 0);
++	}
++	/* allocate any new rows */
++	for (/*i = MIN(row, term.row) */; i < row; i++) {
++		term.line[i] = xmalloc(col * sizeof(Glyph));
++		for (j = 0; j < col; j++)
++			tclearglyph(&term.line[i][j], 0);
++	}
++	/* update cursor */
++	if (term.c.x >= col) {
++		term.c.state &= ~CURSOR_WRAPNEXT;
++		term.c.x = col - 1;
++	} else {
++		UPDATEWRAPNEXT(1, col);
++	}
++	/* update terminal size */
++	term.col = col, term.row = row;
++	/* reset scrolling region */
++	term.top = 0, term.bot = row - 1;
++	/* dirty all lines */
++	tfulldirt();
+ }
+ 
+ void
+@@ -2709,9 +3057,8 @@ draw(void)
+ 		cx--;
+ 
+ 	drawregion(0, 0, term.col, term.row);
+-	if (term.scr == 0)
+-		xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+-				term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
++	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;
+ 	xfinishdraw();
+diff --git a/st.h b/st.h
+index 818a6f8..514ec08 100644
+--- a/st.h
++++ b/st.h
+@@ -22,17 +22,19 @@
+ 
+ enum glyph_attribute {
+ 	ATTR_NULL       = 0,
+-	ATTR_BOLD       = 1 << 0,
+-	ATTR_FAINT      = 1 << 1,
+-	ATTR_ITALIC     = 1 << 2,
+-	ATTR_UNDERLINE  = 1 << 3,
+-	ATTR_BLINK      = 1 << 4,
+-	ATTR_REVERSE    = 1 << 5,
+-	ATTR_INVISIBLE  = 1 << 6,
+-	ATTR_STRUCK     = 1 << 7,
+-	ATTR_WRAP       = 1 << 8,
+-	ATTR_WIDE       = 1 << 9,
+-	ATTR_WDUMMY     = 1 << 10,
++	ATTR_SET        = 1 << 0,
++	ATTR_BOLD       = 1 << 1,
++	ATTR_FAINT      = 1 << 2,
++	ATTR_ITALIC     = 1 << 3,
++	ATTR_UNDERLINE  = 1 << 4,
++	ATTR_BLINK      = 1 << 5,
++	ATTR_REVERSE    = 1 << 6,
++	ATTR_INVISIBLE  = 1 << 7,
++	ATTR_STRUCK     = 1 << 8,
++	ATTR_WRAP       = 1 << 9,
++	ATTR_WIDE       = 1 << 10,
++	ATTR_WDUMMY     = 1 << 11,
++	ATTR_SELECTED   = 1 << 12,
+ 	ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
+ };
+ 
+@@ -90,6 +92,7 @@ void toggleprinter(const Arg *);
+ 
+ int tattrset(int);
+ void tnew(int, int);
++int tisaltscreen(void);
+ void tresize(int, int);
+ void tsetdirtattr(int);
+ void ttyhangup(void);
diff --git a/st.c b/st.c
index 2490d4c..22bef3c 100644
--- a/st.c
+++ b/st.c
@@ -36,6 +36,7 @@
 #define STR_BUF_SIZ   ESC_BUF_SIZ
 #define STR_ARG_SIZ   ESC_ARG_SIZ
 #define HISTSIZE      2000
+#define RESIZEBUFFER  1000
 
 /* macros */
 #define IS_SET(flag)		((term.mode & (flag)) != 0)
@@ -43,9 +44,22 @@
 #define ISCONTROLC1(c)		(BETWEEN(c, 0x80, 0x9f))
 #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
 #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
-#define TLINE(y)		((y) < term.scr ? term.hist[((y) + term.histi - \
-				term.scr + HISTSIZE + 1) % HISTSIZE] : \
-				term.line[(y) - term.scr])
+
+#define TLINE(y) ( \
+	(y) < term.scr ? term.hist[(term.histi + (y) - term.scr + 1 + HISTSIZE) % HISTSIZE] \
+	               : term.line[(y) - term.scr] \
+)
+
+#define TLINEABS(y) ( \
+	(y) < 0 ? term.hist[(term.histi + (y) + 1 + HISTSIZE) % HISTSIZE] : term.line[(y)] \
+)
+
+#define UPDATEWRAPNEXT(alt, col) do { \
+	if ((term.c.state & CURSOR_WRAPNEXT) && term.c.x + term.wrapcwidth[alt] < col) { \
+		term.c.x += term.wrapcwidth[alt]; \
+		term.c.state &= ~CURSOR_WRAPNEXT; \
+	} \
+} while (0);
 
 enum term_mode {
 	MODE_WRAP        = 1 << 0,
@@ -57,6 +71,12 @@ enum term_mode {
 	MODE_UTF8        = 1 << 6,
 };
 
+enum scroll_mode {
+	SCROLL_RESIZE = -1,
+	SCROLL_NOSAVEHIST = 0,
+	SCROLL_SAVEHIST = 1
+};
+
 enum cursor_movement {
 	CURSOR_SAVE,
 	CURSOR_LOAD
@@ -118,10 +138,11 @@ typedef struct {
 	int row;      /* nb row */
 	int col;      /* nb col */
 	Line *line;   /* screen */
-	Line *alt;    /* alternate screen */
 	Line hist[HISTSIZE]; /* history buffer */
-	int histi;    /* history index */
-	int scr;      /* scroll back */
+	int histi;           /* history index */
+	int histf;           /* nb history available */
+	int scr;             /* scroll back */
+	int wrapcwidth[2];   /* used in updating WRAPNEXT when resizing */
 	int *dirty;   /* dirtyness of lines */
 	TCursor c;    /* cursor */
 	int ocx;      /* old cursor col */
@@ -184,26 +205,37 @@ static void tprinter(char *, size_t);
 static void tdumpsel(void);
 static void tdumpline(int);
 static void tdump(void);
-static void tclearregion(int, int, int, int);
+static void tclearregion(int, int, int, int, int);
 static void tcursor(int);
+static void tclearglyph(Glyph *, int);
+static void tresetcursor(void);
 static void tdeletechar(int);
 static void tdeleteline(int);
 static void tinsertblank(int);
 static void tinsertblankline(int);
-static int tlinelen(int);
+static int tlinelen(Line len);
+static int tiswrapped(Line line);
+static char *tgetglyphs(char *, const Glyph *, const Glyph *);
+static size_t tgetline(char *, const Glyph *);
 static void tmoveto(int, int);
 static void tmoveato(int, int);
 static void tnewline(int);
 static void tputtab(int);
 static void tputc(Rune);
 static void treset(void);
-static void tscrollup(int, int, int);
-static void tscrolldown(int, int, int);
+static void tscrollup(int, int, int, int);
+static void tscrolldown(int, int);
+static void treflow(int, int);
+static void rscrolldown(int);
+static void tresizedef(int, int);
+static void tresizealt(int, int);
 static void tsetattr(const int *, int);
 static void tsetchar(Rune, const Glyph *, int, int);
 static void tsetdirt(int, int);
 static void tsetscroll(int, int);
 static void tswapscreen(void);
+static void tloaddefscreen(int, int);
+static void tloadaltscreen(int, int);
 static void tsetmode(int, int, const int *, int);
 static int twrite(const char *, int, int);
 static void tcontrolcode(uchar );
@@ -217,7 +249,10 @@ static int daddch(URLdfa *, char);
 static void drawregion(int, int, int, int);
 
 static void selnormalize(void);
-static void selscroll(int, int);
+static void selscroll(int, int, int);
+static void selmove(int);
+static void selremove(void);
+static int regionselected(int, int, int, int);
 static void selsnap(int *, int *, int);
 
 static size_t utf8decode(const char *, Rune *, size_t);
@@ -417,17 +452,46 @@ selinit(void)
 }
 
 int
-tlinelen(int y)
+tlinelen(Line line)
 {
-	int i = term.col;
+	int i = term.col - 1;
+
+	for (; i >= 0 && !(line[i].mode & (ATTR_SET | ATTR_WRAP)); i--);
+	return i + 1;
+}
 
-	if (TLINE(y)[i - 1].mode & ATTR_WRAP)
-		return i;
+int
+tiswrapped(Line line)
+{
+	int len = tlinelen(line);
 
-	while (i > 0 && TLINE(y)[i - 1].u == ' ')
-		--i;
+	return len > 0 && (line[len - 1].mode & ATTR_WRAP);
+}
 
-	return i;
+char *
+tgetglyphs(char *buf, const Glyph *gp, const Glyph *lgp)
+{
+	while (gp <= lgp)
+		if (gp->mode & ATTR_WDUMMY) {
+			gp++;
+		} else {
+			buf += utf8encode((gp++)->u, buf);
+		}
+	return buf;
+}
+
+size_t
+tgetline(char *buf, const Glyph *fgp)
+{
+	char *ptr;
+	const Glyph *lgp = &fgp[term.col - 1];
+
+	while (lgp > fgp && !(lgp->mode & (ATTR_SET | ATTR_WRAP)))
+		lgp--;
+	ptr = tgetglyphs(buf, fgp, lgp);
+	if (!(lgp->mode & ATTR_WRAP))
+		*(ptr++) = '\n';
+	return ptr - buf;
 }
 
 void
@@ -467,10 +531,11 @@ selextend(int col, int row, int type, int done)
 
 	sel.oe.x = col;
 	sel.oe.y = row;
-	selnormalize();
 	sel.type = type;
+	selnormalize();
 
-	if (oldey != sel.oe.y || oldex != sel.oe.x || oldtype != sel.type || sel.mode == SEL_EMPTY)
+	if (oldey != sel.oe.y || oldex != sel.oe.x ||
+	    oldtype != sel.type || sel.mode == SEL_EMPTY)
 		tsetdirt(MIN(sel.nb.y, oldsby), MAX(sel.ne.y, oldsey));
 
 	sel.mode = done ? SEL_IDLE : SEL_READY;
@@ -497,36 +562,43 @@ selnormalize(void)
 	/* expand selection over line breaks */
 	if (sel.type == SEL_RECTANGULAR)
 		return;
-	i = tlinelen(sel.nb.y);
-	if (i < sel.nb.x)
+
+  i = tlinelen(TLINE(sel.nb.y));
+	if (sel.nb.x > i)
 		sel.nb.x = i;
-	if (tlinelen(sel.ne.y) <= sel.ne.x)
-		sel.ne.x = term.col - 1;
+  if (sel.ne.x >= tlinelen(TLINE(sel.ne.y)))
+    sel.ne.x = term.col - 1;
 }
 
 int
-selected(int x, int y)
+regionselected(int x1, int y1, int x2, int y2)
 {
-	if (sel.mode == SEL_EMPTY || sel.ob.x == -1 ||
-			sel.alt != IS_SET(MODE_ALTSCREEN))
+	if (sel.ob.x == -1 || sel.mode == SEL_EMPTY ||
+	    sel.alt != IS_SET(MODE_ALTSCREEN) || sel.nb.y > y2 || sel.ne.y < y1)
 		return 0;
 
-	if (sel.type == SEL_RECTANGULAR)
-		return BETWEEN(y, sel.nb.y, sel.ne.y)
-		    && BETWEEN(x, sel.nb.x, sel.ne.x);
+	return (sel.type == SEL_RECTANGULAR) ? sel.nb.x <= x2 && sel.ne.x >= x1
+		: (sel.nb.y != y2 || sel.nb.x <= x2) &&
+		  (sel.ne.y != y1 || sel.ne.x >= x1);
+}
 
-	return BETWEEN(y, sel.nb.y, sel.ne.y)
-	    && (y != sel.nb.y || x >= sel.nb.x)
-	    && (y != sel.ne.y || x <= sel.ne.x);
+int
+selected(int x, int y)
+{
+	return regionselected(x, y, x, y);
 }
 
 void
 selsnap(int *x, int *y, int direction)
 {
 	int newx, newy, xt, yt;
+	int rtop = 0, rbot = term.row - 1;
 	int delim, prevdelim;
 	const Glyph *gp, *prevgp;
 
+	if (!IS_SET(MODE_ALTSCREEN))
+		rtop += -term.histf + term.scr, rbot += term.scr;
+
 	switch (sel.snap) {
 	case SNAP_WORD:
 		/*
@@ -541,7 +613,7 @@ selsnap(int *x, int *y, int direction)
 			if (!BETWEEN(newx, 0, term.col - 1)) {
 				newy += direction;
 				newx = (newx + term.col) % term.col;
-				if (!BETWEEN(newy, 0, term.row - 1))
+				if (!BETWEEN(newy, rtop, rbot))
 					break;
 
 				if (direction > 0)
@@ -552,13 +624,13 @@ selsnap(int *x, int *y, int direction)
 					break;
 			}
 
-			if (newx >= tlinelen(newy))
+			if (newx >= tlinelen(TLINE(newy)))
 				break;
 
 			gp = &TLINE(newy)[newx];
 			delim = ISDELIM(gp->u);
-			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
-					|| (delim && gp->u != prevgp->u)))
+			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim ||
+			    (delim && !(gp->u == ' ' && prevgp->u == ' '))))
 				break;
 
 			*x = newx;
@@ -575,18 +647,14 @@ selsnap(int *x, int *y, int direction)
 		 */
 		*x = (direction < 0) ? 0 : term.col - 1;
 		if (direction < 0) {
-			for (; *y > 0; *y += direction) {
-				if (!(TLINE(*y-1)[term.col-1].mode
-						& ATTR_WRAP)) {
+			for (; *y > rtop; *y -= 1) {
+				if (!tiswrapped(TLINE(*y-1)))
 					break;
-				}
 			}
 		} else if (direction > 0) {
-			for (; *y < term.row-1; *y += direction) {
-				if (!(TLINE(*y)[term.col-1].mode
-						& ATTR_WRAP)) {
+			for (; *y < rbot; *y += 1) {
+				if (!tiswrapped(TLINE(*y)))
 					break;
-				}
 			}
 		}
 		break;
@@ -597,40 +665,34 @@ char *
 getsel(void)
 {
 	char *str, *ptr;
-	int y, bufsize, lastx, linelen;
-	const Glyph *gp, *last;
+	int y, lastx, linelen;
+	const Glyph *gp, *lgp;
 
-	if (sel.ob.x == -1)
+	if (sel.ob.x == -1 || sel.alt != IS_SET(MODE_ALTSCREEN))
 		return NULL;
 
-	bufsize = (term.col+1) * (sel.ne.y-sel.nb.y+1) * UTF_SIZ;
-	ptr = str = xmalloc(bufsize);
+	str = xmalloc((term.col + 1) * (sel.ne.y - sel.nb.y + 1) * UTF_SIZ);
+	ptr = str;
 
 	/* append every set & selected glyph to the selection */
 	for (y = sel.nb.y; y <= sel.ne.y; y++) {
-		if ((linelen = tlinelen(y)) == 0) {
+		Line line = TLINE(y);
+
+		if ((linelen = tlinelen(line)) == 0) {
 			*ptr++ = '\n';
 			continue;
 		}
 
 		if (sel.type == SEL_RECTANGULAR) {
-			gp = &TLINE(y)[sel.nb.x];
+			gp = &line[sel.nb.x];
 			lastx = sel.ne.x;
 		} else {
-			gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
+			gp = &line[sel.nb.y == y ? sel.nb.x : 0];
 			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
 		}
-		last = &TLINE(y)[MIN(lastx, linelen-1)];
-		while (last >= gp && last->u == ' ')
-			--last;
-
-		for ( ; gp <= last; ++gp) {
-			if (gp->mode & ATTR_WDUMMY)
-				continue;
-
-			ptr += utf8encode(gp->u, ptr);
-		}
+		lgp = &line[MIN(lastx, linelen-1)];
 
+		ptr = tgetglyphs(ptr, gp, lgp);
 		/*
 		 * Copy and pasting of line endings is inconsistent
 		 * in the inconsistent terminal and GUI world.
@@ -641,10 +703,10 @@ getsel(void)
 		 * FIXME: Fix the computer world.
 		 */
 		if ((y < sel.ne.y || lastx >= linelen) &&
-		    (!(last->mode & ATTR_WRAP) || sel.type == SEL_RECTANGULAR))
+		    (!(lgp->mode & ATTR_WRAP) || sel.type == SEL_RECTANGULAR))
 			*ptr++ = '\n';
 	}
-	*ptr = 0;
+	*ptr = '\0';
 	return str;
 }
 
@@ -653,9 +715,15 @@ selclear(void)
 {
 	if (sel.ob.x == -1)
 		return;
+	selremove();
+	tsetdirt(sel.nb.y, sel.ne.y);
+}
+
+void
+selremove(void)
+{
 	sel.mode = SEL_IDLE;
 	sel.ob.x = -1;
-	tsetdirt(sel.nb.y, sel.ne.y);
 }
 
 void
@@ -856,10 +924,8 @@ void
 ttywrite(const char *s, size_t n, int may_echo)
 {
 	const char *next;
-	Arg arg = (Arg) { .i = term.scr };
-
-	kscrolldown(&arg);
 
+	kscrolldown(&((Arg){ .i = term.scr }));
 	if (may_echo && IS_SET(MODE_ECHO))
 		twrite(s, n, 1);
 
@@ -995,7 +1061,7 @@ tsetdirtattr(int attr)
 	for (i = 0; i < term.row-1; i++) {
 		for (j = 0; j < term.col-1; j++) {
 			if (term.line[i][j].mode & attr) {
-				tsetdirt(i, i);
+				term.dirty[i] = 1;
 				break;
 			}
 		}
@@ -1005,7 +1071,8 @@ tsetdirtattr(int attr)
 void
 tfulldirt(void)
 {
-	tsetdirt(0, term.row-1);
+  for (int i = 0; i < term.row; i++)
+		term.dirty[i] = 1;
 }
 
 void
@@ -1023,50 +1090,115 @@ tcursor(int mode)
 }
 
 void
+tresetcursor(void)
+{
+	term.c = (TCursor){ { .mode = ATTR_NULL, .fg = defaultfg, .bg = defaultbg },
+	                    .x = 0, .y = 0, .state = CURSOR_DEFAULT };
+}
+
+void
 treset(void)
 {
 	uint i;
+  int x, y;
 
-	term.c = (TCursor){{
-		.mode = ATTR_NULL,
-		.fg = defaultfg,
-		.bg = defaultbg
-	}, .x = 0, .y = 0, .state = CURSOR_DEFAULT};
+	tresetcursor();
 
 	memset(term.tabs, 0, term.col * sizeof(*term.tabs));
 	for (i = tabspaces; i < term.col; i += tabspaces)
 		term.tabs[i] = 1;
 	term.top = 0;
+	term.histf = 0;
+	term.scr = 0;
 	term.bot = term.row - 1;
 	term.mode = MODE_WRAP|MODE_UTF8;
 	memset(term.trantbl, CS_USA, sizeof(term.trantbl));
 	term.charset = 0;
 
+  selremove();
 	for (i = 0; i < 2; i++) {
-		tmoveto(0, 0);
-		tcursor(CURSOR_SAVE);
-		tclearregion(0, 0, term.col-1, term.row-1);
+  	tcursor(CURSOR_SAVE); /* reset saved cursor */
+		for (y = 0; y < term.row; y++)
+			for (x = 0; x < term.col; x++)
+				tclearglyph(&term.line[y][x], 0);
 		tswapscreen();
 	}
+  tfulldirt();
 }
 
 void
 tnew(int col, int row)
 {
-	term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
-	tresize(col, row);
-	treset();
+	int i, j;
+
+	for (i = 0; i < 2; i++) {
+		term.line = xmalloc(row * sizeof(Line));
+		for (j = 0; j < row; j++)
+			term.line[j] = xmalloc(col * sizeof(Glyph));
+		term.col = col, term.row = row;
+		tswapscreen();
+	}
+	term.dirty = xmalloc(row * sizeof(*term.dirty));
+	term.tabs = xmalloc(col * sizeof(*term.tabs));
+	for (i = 0; i < HISTSIZE; i++)
+		term.hist[i] = xmalloc(col * sizeof(Glyph));
+  treset();
 }
 
+/* handle it with care */
 void
 tswapscreen(void)
 {
-	Line *tmp = term.line;
+	static Line *altline;
+	static int altcol, altrow;
+	Line *tmpline = term.line;
+	int tmpcol = term.col, tmprow = term.row;
 
-	term.line = term.alt;
-	term.alt = tmp;
+	term.line = altline;
+	term.col = altcol, term.row = altrow;
+	altline = tmpline;
+	altcol = tmpcol, altrow = tmprow;
 	term.mode ^= MODE_ALTSCREEN;
-	tfulldirt();
+}
+
+void
+tloaddefscreen(int clear, int loadcursor)
+{
+	int col, row, alt = IS_SET(MODE_ALTSCREEN);
+
+	if (alt) {
+		if (clear)
+			tclearregion(0, 0, term.col-1, term.row-1, 1);
+		col = term.col, row = term.row;
+		tswapscreen();
+	}
+	if (loadcursor)
+		tcursor(CURSOR_LOAD);
+	if (alt)
+		tresizedef(col, row);
+}
+
+void
+tloadaltscreen(int clear, int savecursor)
+{
+	int col, row, def = !IS_SET(MODE_ALTSCREEN);
+
+	if (savecursor)
+		tcursor(CURSOR_SAVE);
+	if (def) {
+		col = term.col, row = term.row;
+		tswapscreen();
+		term.scr = 0;
+		tresizealt(col, row);
+	}
+	if (clear)
+		tclearregion(0, 0, term.col-1, term.row-1, 1);
+}
+
+int
+tisaltscreen(void)
+{
+	return IS_SET(MODE_ALTSCREEN);
 }
 
 void
@@ -1074,17 +1206,22 @@ kscrolldown(const Arg* a)
 {
 	int n = a->i;
 
-	if (n < 0)
-		n = term.row + n;
+	if (!term.scr || IS_SET(MODE_ALTSCREEN))
+		return;
 
-	if (n > term.scr)
-		n = term.scr;
+	if (n < 0)
+		n = MAX(term.row / -n, 1);
 
-	if (term.scr > 0) {
+	if (n <= term.scr) {
 		term.scr -= n;
-		selscroll(0, -n);
-		tfulldirt();
+	} else {
+		n = term.scr;
+		term.scr = 0;
 	}
+
+	if (sel.ob.x != -1 && !sel.alt)
+		selmove(-n); /* negate change in term.scr */
+	tfulldirt();
 }
 
 void
@@ -1092,92 +1229,118 @@ kscrollup(const Arg* a)
 {
 	int n = a->i;
 
+	if (!term.histf || IS_SET(MODE_ALTSCREEN))
+		return;
+
 	if (n < 0)
-		n = term.row + n;
+		n = MAX(term.row / -n, 1);
 
-	if (term.scr <= HISTSIZE-n) {
+	if (term.scr + n <= term.histf) {
 		term.scr += n;
-		selscroll(0, n);
-		tfulldirt();
+	} else {
+		n = term.histf - term.scr;
+		term.scr = term.histf;
 	}
+
+	if (sel.ob.x != -1 && !sel.alt)
+		selmove(n); /* negate change in term.scr */
+	tfulldirt();
 }
 
 void
-tscrolldown(int orig, int n, int copyhist)
+tscrolldown(int top, int n)
 {
-	int i;
+	int i, bot = term.bot;
 	Line temp;
 
-	LIMIT(n, 0, term.bot-orig+1);
-	if (copyhist) {
-		term.histi = (term.histi - 1 + HISTSIZE) % HISTSIZE;
-		temp = term.hist[term.histi];
-		term.hist[term.histi] = term.line[term.bot];
-		term.line[term.bot] = temp;
-	}
-
+	if (n <= 0)
+		return;
+	n = MIN(n, bot-top+1);
 
-	tsetdirt(orig, term.bot-n);
-	tclearregion(0, term.bot-n+1, term.col-1, term.bot);
+	tsetdirt(top, bot-n);
+	tclearregion(0, bot-n+1, term.col-1, bot, 1);
 
-	for (i = term.bot; i >= orig+n; i--) {
+	for (i = bot; i >= top+n; i--) {
 		temp = term.line[i];
 		term.line[i] = term.line[i-n];
 		term.line[i-n] = temp;
 	}
 
-	if (term.scr == 0)
-		selscroll(orig, n);
+	if (sel.ob.x != -1 && sel.alt == IS_SET(MODE_ALTSCREEN))
+		selscroll(top, bot, n);
 }
 
 void
-tscrollup(int orig, int n, int copyhist)
+tscrollup(int top, int bot, int n, int mode)
 {
-	int i;
+	int i, j, s;
+	int alt = IS_SET(MODE_ALTSCREEN);
+	int savehist = !alt && top == 0 && mode != SCROLL_NOSAVEHIST;
 	Line temp;
 
-	LIMIT(n, 0, term.bot-orig+1);
-
-	if (copyhist) {
-		term.histi = (term.histi + 1) % HISTSIZE;
-		temp = term.hist[term.histi];
-		term.hist[term.histi] = term.line[orig];
-		term.line[orig] = temp;
+	if (n <= 0)
+		return;
+	n = MIN(n, bot-top+1);
+
+	if (savehist) {
+		for (i = 0; i < n; i++) {
+			term.histi = (term.histi + 1) % HISTSIZE;
+			temp = term.hist[term.histi];
+			for (j = 0; j < term.col; j++)
+				tclearglyph(&temp[j], 1);
+			term.hist[term.histi] = term.line[i];
+			term.line[i] = temp;
+		}
+		term.histf = MIN(term.histf + n, HISTSIZE);
+		s = n;
+		if (term.scr) {
+			j = term.scr;
+			term.scr = MIN(j + n, HISTSIZE);
+			s = j + n - term.scr;
+		}
+		if (mode != SCROLL_RESIZE)
+			tfulldirt();
+	} else {
+		tclearregion(0, top, term.col-1, top+n-1, 1);
+		tsetdirt(top+n, bot);
 	}
 
-	if (term.scr > 0 && term.scr < HISTSIZE)
-		term.scr = MIN(term.scr + n, HISTSIZE-1);
-
-	tclearregion(0, orig, term.col-1, orig+n-1);
-	tsetdirt(orig+n, term.bot);
-
-	for (i = orig; i <= term.bot-n; i++) {
+	for (i = top; i <= bot-n; i++) {
 		temp = term.line[i];
 		term.line[i] = term.line[i+n];
 		term.line[i+n] = temp;
 	}
 
-	if (term.scr == 0)
-		selscroll(orig, -n);
+	if (sel.ob.x != -1 && sel.alt == alt) {
+		if (!savehist) {
+			selscroll(top, bot, -n);
+		} else if (s > 0) {
+			selmove(-s);
+			if (-term.scr + sel.nb.y < -term.histf)
+				selremove();
+		}
+	}
 }
 
 void
-selscroll(int orig, int n)
+selmove(int n)
 {
-	if (sel.ob.x == -1)
-		return;
+	sel.ob.y += n, sel.nb.y += n;
+	sel.oe.y += n, sel.ne.y += n;
+}
 
-	if (BETWEEN(sel.nb.y, orig, term.bot) != BETWEEN(sel.ne.y, orig, term.bot)) {
+void
+selscroll(int top, int bot, int n)
+{
+	/* turn absolute coordinates into relative */
+	top += term.scr, bot += term.scr;
+
+	if (BETWEEN(sel.nb.y, top, bot) != BETWEEN(sel.ne.y, top, 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) {
+	} else if (BETWEEN(sel.nb.y, top, bot)) {
+		selmove(n);
+		if (sel.nb.y < top || sel.ne.y > bot)
 			selclear();
-		} else {
-			selnormalize();
-		}
 	}
 }
 
@@ -1187,7 +1350,7 @@ tnewline(int first_col)
 	int y = term.c.y;
 
 	if (y == term.bot) {
-		tscrollup(term.top, 1, 1);
+		tscrollup(term.top, term.bot, 1, SCROLL_SAVEHIST);
 	} else {
 		y++;
 	}
@@ -1282,13 +1445,28 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
 	term.dirty[y] = 1;
 	term.line[y][x] = *attr;
 	term.line[y][x].u = u;
+        term.line[y][x].mode |= ATTR_SET;
 
 	if (isboxdraw(u))
 		term.line[y][x].mode |= ATTR_BOXDRAW;
 }
 
 void
-tclearregion(int x1, int y1, int x2, int y2)
+tclearglyph(Glyph *gp, int usecurattr)
+{
+      if (usecurattr) {
+            gp->fg = term.c.attr.fg;
+            gp->bg = term.c.attr.bg;
+      } else {
+            gp->fg = defaultfg;
+            gp->bg = defaultbg;
+      }
+      gp->mode =ATTR_NULL;
+      gp->u = ' ';
+}
+
+void
+tclearregion(int x1, int y1, int x2, int y2, int usecurattr)
 {
 	int x, y, temp;
 	Glyph *gp;
@@ -1298,71 +1476,68 @@ tclearregion(int x1, int y1, int x2, int y2)
 	if (y1 > y2)
 		temp = y1, y1 = y2, y2 = temp;
 
-	LIMIT(x1, 0, term.col-1);
-	LIMIT(x2, 0, term.col-1);
-	LIMIT(y1, 0, term.row-1);
-	LIMIT(y2, 0, term.row-1);
+        /* regionselected() takes relative coordinates */
+        if (regionselected(x1+term.scr, y1+term.scr, x2+term.scr, y2+term.scr))
+                selremove();
 
 	for (y = y1; y <= y2; y++) {
 		term.dirty[y] = 1;
-		for (x = x1; x <= x2; x++) {
-			gp = &term.line[y][x];
-			if (selected(x, y))
-				selclear();
-			gp->fg = term.c.attr.fg;
-			gp->bg = term.c.attr.bg;
-			gp->mode = 0;
-			gp->u = ' ';
-		}
+                for (x = x1; x <= x2; x++)
+                        tclearglyph(&term.line[y][x], usecurattr);
 	}
 }
 
 void
 tdeletechar(int n)
 {
-	int dst, src, size;
-	Glyph *line;
-
-	LIMIT(n, 0, term.col - term.c.x);
+        int src, dst, size;
+        Line line;
 
+        if (n <= 0)
+                return;
 	dst = term.c.x;
-	src = term.c.x + n;
+	src = MIN(term.c.x + n,term.col);
 	size = term.col - src;
-	line = term.line[term.c.y];
 
-	memmove(&line[dst], &line[src], size * sizeof(Glyph));
-	tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
+        if (size > 0) { /* otherwise src would point beyond the array
+                           https://stackoverflow.com/questions/29844298 */
+                line = term.line[term.c.y];
+                memmove(&line[dst], &line[src], size + sizeof(Glyph));
+        }
+        tclearregion(dst + size, term.c.y, term.col - 1, term.c.y, 1);
 }
 
 void
 tinsertblank(int n)
 {
-	int dst, src, size;
-	Glyph *line;
+	int src, dst, size;
+	Line line;
 
-	LIMIT(n, 0, term.col - term.c.x);
-
-	dst = term.c.x + n;
+        if (n <= 0)
+                return;
+        dst= MIN(term.c.x + n, term.col);
 	src = term.c.x;
 	size = term.col - dst;
-	line = term.line[term.c.y];
 
-	memmove(&line[dst], &line[src], size * sizeof(Glyph));
-	tclearregion(src, term.c.y, dst - 1, term.c.y);
+        if (size > 0) { /* otherwise dst would point beyond the array */
+                line = term.line[term.c.y];
+                memmove(&line[dst], &line[src], size * sizeof(Glyph));
+        }
+        tclearregion(src, term.c.y, dst - 1, term.c.y, 1);
 }
 
 void
 tinsertblankline(int n)
 {
 	if (BETWEEN(term.c.y, term.top, term.bot))
-		tscrolldown(term.c.y, n, 0);
+		tscrolldown(term.c.y, n);
 }
 
 void
 tdeleteline(int n)
 {
 	if (BETWEEN(term.c.y, term.top, term.bot))
-		tscrollup(term.c.y, n, 0);
+		tscrollup(term.c.y, term.bot, n, SCROLL_NOSAVEHIST);
 }
 
 int32_t
@@ -1536,7 +1711,7 @@ tsetscroll(int t, int b)
 void
 tsetmode(int priv, int set, const int *args, int narg)
 {
-	int alt; const int *lim;
+	const int *lim;
 
 	for (lim = args + narg; args < lim; ++args) {
 		if (priv) {
@@ -1597,25 +1772,18 @@ tsetmode(int priv, int set, const int *args, int narg)
 				xsetmode(set, MODE_8BIT);
 				break;
 			case 1049: /* swap screen & set/restore cursor as xterm */
-				if (!allowaltscreen)
-					break;
-				tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
-				/* FALLTHROUGH */
 			case 47: /* swap screen */
-			case 1047:
+			case 1047: /* swap screen, clearing alternate screen */
 				if (!allowaltscreen)
 					break;
-				alt = IS_SET(MODE_ALTSCREEN);
-				if (alt) {
-					tclearregion(0, 0, term.col-1,
-							term.row-1);
-				}
-				if (set ^ alt) /* set is always 1 or 0 */
-					tswapscreen();
-				if (*args != 1049)
-					break;
-				/* FALLTHROUGH */
+				if (set)
+					tloadaltscreen(*args == 1049, *args == 1049);
+				else
+					tloaddefscreen(*args == 1047, *args == 1049);
+				break;
 			case 1048:
+				if (!allowaltscreen)
+          break;
 				tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
 				break;
 			case 2004: /* 2004: bracketed paste mode */
@@ -1667,7 +1835,7 @@ void
 csihandle(void)
 {
 	char buf[40];
-	int len;
+	int n, x;
 
 	switch (csiescseq.mode[0]) {
 	default:
@@ -1765,20 +1933,30 @@ csihandle(void)
 	case 'J': /* ED -- Clear screen */
 		switch (csiescseq.arg[0]) {
 		case 0: /* below */
-			tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
+			tclearregion(term.c.x, term.c.y, term.col-1, term.c.y, 1);
 			if (term.c.y < term.row-1) {
-				tclearregion(0, term.c.y+1, term.col-1,
-						term.row-1);
+				tclearregion(0, term.c.y+1, term.col-1, term.row-1, 1);
 			}
 			break;
 		case 1: /* above */
-			if (term.c.y > 1)
-				tclearregion(0, 0, term.col-1, term.c.y-1);
-			tclearregion(0, term.c.y, term.c.x, term.c.y);
+			if (term.c.y >= 1)
+				tclearregion(0, 0, term.col-1, term.c.y-1, 1);
+			tclearregion(0, term.c.y, term.c.x, term.c.y, 1);
 			break;
 		case 2: /* all */
-			tclearregion(0, 0, term.col-1, term.row-1);
-			break;
+			if (IS_SET(MODE_ALTSCREEN)) {
+  			tclearregion(0, 0, term.col-1, term.row-1, 1);
+  			break;
+      }
+			/* vte does this:
+			tscrollup(0, term.row-1, term.row, SCROLL_SAVEHIST); */
+      
+			/* alacritty does this: */
+			for (n = term.row-1; n >= 0 && tlinelen(term.line[n]) == 0; n--);
+			if (n >= 0)
+				tscrollup(0, term.row-1, n+1, SCROLL_SAVEHIST);
+			tscrollup(0, term.row-1, term.row-n-1, SCROLL_NOSAVEHIST);
+      break;
 		default:
 			goto unknown;
 		}
@@ -1786,24 +1964,24 @@ csihandle(void)
 	case 'K': /* EL -- Clear line */
 		switch (csiescseq.arg[0]) {
 		case 0: /* right */
-			tclearregion(term.c.x, term.c.y, term.col-1,
-					term.c.y);
+			tclearregion(term.c.x, term.c.y, term.col-1, term.c.y, 1);
 			break;
 		case 1: /* left */
-			tclearregion(0, term.c.y, term.c.x, term.c.y);
+			tclearregion(0, term.c.y, term.c.x, term.c.y, 1);
 			break;
 		case 2: /* all */
-			tclearregion(0, term.c.y, term.col-1, term.c.y);
+			tclearregion(0, term.c.y, term.col-1, term.c.y, 1);
 			break;
 		}
 		break;
 	case 'S': /* SU -- Scroll <n> line up */
 		DEFAULT(csiescseq.arg[0], 1);
-		tscrollup(term.top, csiescseq.arg[0], 0);
+		/* xterm, urxvt, alacritty save this in history */
+		tscrollup(term.top, term.bot, csiescseq.arg[0], SCROLL_SAVEHIST);
 		break;
 	case 'T': /* SD -- Scroll <n> line down */
 		DEFAULT(csiescseq.arg[0], 1);
-		tscrolldown(term.top, csiescseq.arg[0], 0);
+		tscrolldown(term.top, csiescseq.arg[0]);
 		break;
 	case 'L': /* IL -- Insert <n> blank lines */
 		DEFAULT(csiescseq.arg[0], 1);
@@ -1817,9 +1995,11 @@ csihandle(void)
 		tdeleteline(csiescseq.arg[0]);
 		break;
 	case 'X': /* ECH -- Erase <n> char */
+		if (csiescseq.arg[0] < 0)
+			return;
 		DEFAULT(csiescseq.arg[0], 1);
-		tclearregion(term.c.x, term.c.y,
-				term.c.x + csiescseq.arg[0] - 1, term.c.y);
+		x = MIN(term.c.x + csiescseq.arg[0], term.col) - 1;
+		tclearregion(term.c.x, term.c.y, x, term.c.y, 1);
 		break;
 	case 'P': /* DCH -- Delete <n> char */
 		DEFAULT(csiescseq.arg[0], 1);
@@ -1841,9 +2021,9 @@ csihandle(void)
 		break;
 	case 'n': /* DSR – Device Status Report (cursor position) */
 		if (csiescseq.arg[0] == 6) {
-			len = snprintf(buf, sizeof(buf), "\033[%i;%iR",
+			n = snprintf(buf, sizeof(buf), "\033[%i;%iR",
 					term.c.y+1, term.c.x+1);
-			ttywrite(buf, len, 0);
+			ttywrite(buf, n, 0);
 		}
 		break;
 	case 'r': /* DECSTBM -- Set Scrolling Region */
@@ -2163,16 +2343,8 @@ tdumpsel(void)
 void
 tdumpline(int n)
 {
-	char buf[UTF_SIZ];
-	const Glyph *bp, *end;
-
-	bp = &term.line[n][0];
-	end = &bp[MIN(tlinelen(n), term.col) - 1];
-	if (bp != end || bp->u != ' ') {
-		for ( ; bp <= end; ++bp)
-			tprinter(buf, utf8encode(bp->u, buf));
-	}
-	tprinter("\n", 1);
+	char str[(term.col + 1) * UTF_SIZ];
+  tprinter(str, tgetline(str, &term.line[n][0]));
 }
 
 void
@@ -2393,7 +2565,7 @@ eschandle(uchar ascii)
 		return 0;
 	case 'D': /* IND -- Linefeed */
 		if (term.c.y == term.bot) {
-			tscrollup(term.top, 1, 1);
+			tscrollup(term.top, term.bot, 1, SCROLL_SAVEHIST);
 		} else {
 			tmoveto(term.c.x, term.c.y+1);
 		}
@@ -2406,7 +2578,7 @@ eschandle(uchar ascii)
 		break;
 	case 'M': /* RI -- Reverse index */
 		if (term.c.y == term.top) {
-			tscrolldown(term.top, 1, 1);
+			tscrolldown(term.top, 1);
 		} else {
 			tmoveto(term.c.x, term.c.y-1);
 		}
@@ -2547,7 +2719,8 @@ check_control_code:
 		 */
 		return;
 	}
-	if (selected(term.c.x, term.c.y))
+	/* selected() takes relative coordinates */
+	if (selected(term.c.x + term.scr, term.c.y + term.scr))
 		selclear();
 
 	gp = &term.line[term.c.y][term.c.x];
@@ -2582,6 +2755,7 @@ check_control_code:
 	if (term.c.x+width < term.col) {
 		tmoveto(term.c.x+width, term.c.y);
 	} else {
+		term.wrapcwidth[IS_SET(MODE_ALTSCREEN)] = width;
 		term.c.state |= CURSOR_WRAPNEXT;
 	}
 }
@@ -2619,93 +2793,275 @@ twrite(const char *buf, int buflen, int show_ctrl)
 }
 
 void
-tresize(int col, int row)
+treflow(int col, int row)
 {
 	int i, j;
-	int minrow = MIN(row, term.row);
-	int mincol = MIN(col, term.col);
-	int *bp;
-	TCursor c;
-
-	if (col < 1 || row < 1) {
-		fprintf(stderr,
-		        "tresize: error resizing to %dx%d\n", col, row);
-		return;
+	int oce, nce, bot, scr;
+	int ox = 0, oy = -term.histf, nx = 0, ny = -1, len;
+	int cy = -1; /* proxy for new y coordinate of cursor */
+	int nlines;
+	Line *buf, line;
+
+	/* y coordinate of cursor line end */
+	for (oce = term.c.y; oce < term.row - 1 &&
+	                     tiswrapped(term.line[oce]); oce++);
+
+	nlines = term.histf + oce + 1;
+	if (col < term.col) {
+		/* each line can take this many lines after reflow */
+		j = (term.col + col - 1) / col;
+		nlines = j * nlines;
+		if (nlines > HISTSIZE + RESIZEBUFFER + row) {
+			nlines = HISTSIZE + RESIZEBUFFER + row;
+			oy = -(nlines / j - oce - 1);
+		}
 	}
+	buf = xmalloc(nlines * sizeof(Line));
+	do {
+		if (!nx)
+			buf[++ny] = xmalloc(col * sizeof(Glyph));
+		if (!ox) {
+			line = TLINEABS(oy);
+			len = tlinelen(line);
+		}
+		if (oy == term.c.y) {
+			if (!ox)
+				len = MAX(len, term.c.x + 1);
+			/* update cursor */
+			if (cy < 0 && term.c.x - ox < col - nx) {
+				term.c.x = nx + term.c.x - ox, cy = ny;
+				UPDATEWRAPNEXT(0, col);
+			}
+		}
+		/* get reflowed lines in buf */
+		if (col - nx > len - ox) {
+			memcpy(&buf[ny][nx], &line[ox], (len-ox) * sizeof(Glyph));
+			nx += len - ox;
+			if (len == 0 || !(line[len - 1].mode & ATTR_WRAP)) {
+				for (j = nx; j < col; j++)
+					tclearglyph(&buf[ny][j], 0);
+				nx = 0;
+			} else if (nx > 0) {
+				buf[ny][nx - 1].mode &= ~ATTR_WRAP;
+			}
+			ox = 0, oy++;
+		} else if (col - nx == len - ox) {
+			memcpy(&buf[ny][nx], &line[ox], (col-nx) * sizeof(Glyph));
+			ox = 0, oy++, nx = 0;
+		} else/* if (col - nx < len - ox) */ {
+			memcpy(&buf[ny][nx], &line[ox], (col-nx) * sizeof(Glyph));
+    	ox += col - nx;
+			buf[ny][col - 1].mode |= ATTR_WRAP;
+			nx = 0;
+		}
+	} while (oy <= oce);
+	if (nx)
+		for (j = nx; j < col; j++)
+			tclearglyph(&buf[ny][j], 0);
 
-	/*
-	 * slide screen to keep cursor where we expect it -
-	 * tscrollup would work here, but we can optimize to
-	 * memmove because we're freeing the earlier lines
-	 */
-	for (i = 0; i <= term.c.y - row; i++) {
+	/* free extra lines */
+	for (i = row; i < term.row; i++)
 		free(term.line[i]);
-		free(term.alt[i]);
+	/* resize to new height */
+	term.line = xrealloc(term.line, row * sizeof(Line));
+
+	bot = MIN(ny, row - 1);
+	scr = MAX(row - term.row, 0);
+	/* update y coordinate of cursor line end */
+	nce = MIN(oce + scr, bot);
+	/* update cursor y coordinate */
+	term.c.y = nce - (ny - cy);
+	if (term.c.y < 0) {
+		j = nce, nce = MIN(nce + -term.c.y, bot);
+		term.c.y += nce - j;
+		while (term.c.y < 0) {
+			free(buf[ny--]);
+			term.c.y++;
+		}
 	}
-	/* ensure that both src and dst are not NULL */
-	if (i > 0) {
-		memmove(term.line, term.line + i, row * sizeof(Line));
-		memmove(term.alt, term.alt + i, row * sizeof(Line));
+	/* allocate new rows */
+	for (i = row - 1; i > nce; i--) {
+		term.line[i] = xmalloc(col * sizeof(Glyph));
+		for (j = 0; j < col; j++)
+			tclearglyph(&term.line[i][j], 0);
 	}
-	for (i += row; i < term.row; i++) {
+	/* fill visible area */
+	for (/*i = nce */; i >= term.row; i--, ny--)
+		term.line[i] = buf[ny];
+	for (/*i = term.row - 1 */; i >= 0; i--, ny--) {
 		free(term.line[i]);
-		free(term.alt[i]);
+		term.line[i] = buf[ny];
+	}
+	/* fill lines in history buffer and update term.histf */
+	for (/*i = -1 */; ny >= 0 && i >= -HISTSIZE; i--, ny--) {
+		j = (term.histi + i + 1 + HISTSIZE) % HISTSIZE;
+		free(term.hist[j]);
+		term.hist[j] = buf[ny];
+	}
+	term.histf = -i - 1;
+	term.scr = MIN(term.scr, term.histf);
+	/* resize rest of the history lines */
+	for (/*i = -term.histf - 1 */; i >= -HISTSIZE; i--) {
+		j = (term.histi + i + 1 + HISTSIZE) % HISTSIZE;
+		term.hist[j] = xrealloc(term.hist[j], col * sizeof(Glyph));
 	}
+	free(buf);
+}
 
-	/* resize to new height */
-	term.line = xrealloc(term.line, row * sizeof(Line));
-	term.alt  = xrealloc(term.alt,  row * sizeof(Line));
-	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
-	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
+void
+rscrolldown(int n)
+{
+	int i;
+	Line temp;
 
-	for (i = 0; i < HISTSIZE; i++) {
-		term.hist[i] = xrealloc(term.hist[i], col * sizeof(Glyph));
-		for (j = mincol; j < col; j++) {
-			term.hist[i][j] = term.c.attr;
-			term.hist[i][j].u = ' ';
-		}
-	}
+	/* can never be true as of now
+	if (IS_SET(MODE_ALTSCREEN))
+		return; */
 
-	/* resize each row to new width, zero-pad if needed */
-	for (i = 0; i < minrow; i++) {
-		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
-		term.alt[i]  = xrealloc(term.alt[i],  col * sizeof(Glyph));
-	}
+	if ((n = MIN(n, term.histf)) <= 0)
+		return;
 
-	/* allocate any new rows */
-	for (/* i = minrow */; i < row; i++) {
-		term.line[i] = xmalloc(col * sizeof(Glyph));
-		term.alt[i] = xmalloc(col * sizeof(Glyph));
+	for (i = term.c.y + n; i >= n; i--) {
+		temp = term.line[i];
+		term.line[i] = term.line[i-n];
+		term.line[i-n] = temp;
+	}
+	for (/*i = n - 1 */; i >= 0; i--) {
+		temp = term.line[i];
+		term.line[i] = term.hist[term.histi];
+		term.hist[term.histi] = temp;
+		term.histi = (term.histi - 1 + HISTSIZE) % HISTSIZE;
 	}
+	term.c.y += n;
+	term.histf -= n;
+	if ((i = term.scr - n) >= 0) {
+		term.scr = i;
+	} else {
+		term.scr = 0;
+		if (sel.ob.x != -1 && !sel.alt)
+			selmove(-i);
+	}
+}
+
+void
+tresize(int col, int row)
+{
+	int *bp;
+
+	/* col and row are always MAX(_, 1)
+	if (col < 1 || row < 1) {
+		fprintf(stderr, "tresize: error resizing to %dx%d\n", col, row);
+		return;
+	} */
+
+	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
+	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
 	if (col > term.col) {
 		bp = term.tabs + term.col;
-
 		memset(bp, 0, sizeof(*term.tabs) * (col - term.col));
 		while (--bp > term.tabs && !*bp)
 			/* nothing */ ;
 		for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
 			*bp = 1;
 	}
-	/* update terminal size */
-	term.col = col;
-	term.row = row;
-	/* reset scrolling region */
-	tsetscroll(0, row-1);
-	/* make use of the LIMIT in tmoveto */
-	tmoveto(term.c.x, term.c.y);
-	/* Clearing both screens (it makes dirty all lines) */
-	c = term.c;
-	for (i = 0; i < 2; i++) {
-		if (mincol < col && 0 < minrow) {
-			tclearregion(mincol, 0, col - 1, minrow - 1);
+
+	if (IS_SET(MODE_ALTSCREEN))
+		tresizealt(col, row);
+	else
+		tresizedef(col, row);
+}
+
+void
+tresizedef(int col, int row)
+{
+	int i, j;
+
+	/* return if dimensions haven't changed */
+	if (term.col == col && term.row == row) {
+		tfulldirt();
+		return;
+	}
+	if (col != term.col) {
+		if (!sel.alt)
+			selremove();
+		treflow(col, row);
+	} else {
+		/* slide screen up if otherwise cursor would get out of the screen */
+		if (term.c.y >= row) {
+			tscrollup(0, term.row - 1, term.c.y - row + 1, SCROLL_RESIZE);
+			term.c.y = row - 1;
 		}
-		if (0 < col && minrow < row) {
-			tclearregion(0, minrow, col - 1, row - 1);
+		for (i = row; i < term.row; i++)
+			free(term.line[i]);
+
+		/* resize to new height */
+		term.line = xrealloc(term.line, row * sizeof(Line));
+		/* allocate any new rows */
+		for (i = term.row; i < row; i++) {
+			term.line[i] = xmalloc(col * sizeof(Glyph));
+			for (j = 0; j < col; j++)
+				tclearglyph(&term.line[i][j], 0);
 		}
-		tswapscreen();
-		tcursor(CURSOR_LOAD);
+		/* scroll down as much as height has increased */
+		rscrolldown(row - term.row);
+	}
+	/* update terminal size */
+	term.col = col, term.row = row;
+	/* reset scrolling region */
+	term.top = 0, term.bot = row - 1;
+	/* dirty all lines */
+	tfulldirt();
+}
+
+void
+tresizealt(int col, int row)
+{
+	int i, j;
+
+	/* return if dimensions haven't changed */
+	if (term.col == col && term.row == row) {
+		tfulldirt();
+		return;
+	}
+	if (sel.alt)
+		selremove();
+	/* slide screen up if otherwise cursor would get out of the screen */
+	for (i = 0; i <= term.c.y - row; i++)
+		free(term.line[i]);
+	if (i > 0) {
+		/* ensure that both src and dst are not NULL */
+		memmove(term.line, term.line + i, row * sizeof(Line));
+		term.c.y = row - 1;
+	}
+	for (i += row; i < term.row; i++)
+		free(term.line[i]);
+	/* resize to new height */
+	term.line = xrealloc(term.line, row * sizeof(Line));
+	/* resize to new width */
+	for (i = 0; i < MIN(row, term.row); i++) {
+		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
+		for (j = term.col; j < col; j++)
+			tclearglyph(&term.line[i][j], 0);
 	}
-	term.c = c;
+	/* allocate any new rows */
+	for (/*i = MIN(row, term.row) */; i < row; i++) {
+		term.line[i] = xmalloc(col * sizeof(Glyph));
+		for (j = 0; j < col; j++)
+			tclearglyph(&term.line[i][j], 0);
+	}
+	/* update cursor */
+	if (term.c.x >= col) {
+		term.c.state &= ~CURSOR_WRAPNEXT;
+		term.c.x = col - 1;
+	} else {
+		UPDATEWRAPNEXT(1, col);
+	}
+	/* update terminal size */
+	term.col = col, term.row = row;
+	/* reset scrolling region */
+	term.top = 0, term.bot = row - 1;
+	/* dirty all lines */
+	tfulldirt();
 }
 
 void
@@ -2745,9 +3101,8 @@ draw(void)
 		cx--;
 
 	drawregion(0, 0, term.col, term.row);
-	if (term.scr == 0)
-		xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
-				term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
+	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;
 	xfinishdraw();
diff --git a/st.h b/st.h
index dd83696..5057ceb 100644
--- a/st.h
+++ b/st.h
@@ -22,18 +22,20 @@
 
 enum glyph_attribute {
 	ATTR_NULL       = 0,
-	ATTR_BOLD       = 1 << 0,
-	ATTR_FAINT      = 1 << 1,
-	ATTR_ITALIC     = 1 << 2,
-	ATTR_UNDERLINE  = 1 << 3,
-	ATTR_BLINK      = 1 << 4,
-	ATTR_REVERSE    = 1 << 5,
-	ATTR_INVISIBLE  = 1 << 6,
-	ATTR_STRUCK     = 1 << 7,
-	ATTR_WRAP       = 1 << 8,
-	ATTR_WIDE       = 1 << 9,
-	ATTR_WDUMMY     = 1 << 10,
-	ATTR_BOXDRAW    = 1 << 11,
+	ATTR_SET        = 1 << 0,
+	ATTR_BOLD       = 1 << 1,
+	ATTR_FAINT      = 1 << 2,
+	ATTR_ITALIC     = 1 << 3,
+	ATTR_UNDERLINE  = 1 << 4,
+	ATTR_BLINK      = 1 << 5,
+	ATTR_REVERSE    = 1 << 6,
+	ATTR_INVISIBLE  = 1 << 7,
+	ATTR_STRUCK     = 1 << 8,
+	ATTR_WRAP       = 1 << 9,
+	ATTR_WIDE       = 1 << 10,
+	ATTR_WDUMMY     = 1 << 11,
+	ATTR_SELECTED   = 1 << 12,
+        ATTR_BOXDRAW    = 1 << 13,
 	ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
 };
 
@@ -93,6 +95,7 @@ void copyurl(const Arg *);
 
 int tattrset(int);
 void tnew(int, int);
+int tisaltscreen(void);
 void tresize(int, int);
 void tsetdirtattr(int);
 void ttyhangup(void);