]> git.cameronkatri.com Git - mandoc.git/blobdiff - term.c
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[mandoc.git] / term.c
diff --git a/term.c b/term.c
index 33f8f90027ac802912ebd69433a9e12b536aefa0..661508d985328894f510f73823898f249d68072a 100644 (file)
--- a/term.c
+++ b/term.c
@@ -1,15 +1,15 @@
-/*     $Id: term.c,v 1.237 2014/12/02 10:08:06 schwarze Exp $ */
+/*     $Id: term.c,v 1.268 2017/06/08 12:54:58 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2010-2014 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 #include "main.h"
 
 static size_t           cond_width(const struct termp *, int, int *);
-static void             adjbuf(struct termp *p, size_t);
+static void             adjbuf(struct termp_col *, size_t);
 static void             bufferc(struct termp *, char);
 static void             encode(struct termp *, const char *, size_t);
 static void             encode1(struct termp *, int);
+static void             endline(struct termp *);
 
 
 void
 term_free(struct termp *p)
 {
-
-       free(p->buf);
+       for (p->tcol = p->tcols; p->tcol < p->tcols + p->maxtcol; p->tcol++)
+               free(p->tcol->buf);
+       free(p->tcols);
+       free(p->fontq);
        free(p);
 }
 
 void
 term_begin(struct termp *p, term_margin head,
-               term_margin foot, const void *arg)
+               term_margin foot, const struct roff_meta *arg)
 {
 
        p->headf = head;
@@ -77,75 +80,59 @@ term_end(struct termp *p)
  *    the next column.  However, if less than p->trailspace blanks,
  *    which can be 0, 1, or 2, remain to the right margin, the line
  *    will be broken.
+ *  - TERMP_BRTRSP: Consider trailing whitespace significant
+ *    when deciding whether the chunk fits or not.
  *  - TERMP_BRIND: If the chunk does not fit and the output line has
  *    to be broken, start the next line at the right margin instead
  *    of at the offset.  Used together with TERMP_NOBREAK for the tags
  *    in various kinds of tagged lists.
- *  - TERMP_DANGLE: Do not break the output line at the right margin,
+ *  - TERMP_HANG: Do not break the output line at the right margin,
  *    append the next chunk after it even if this one is too long.
  *    To be used together with TERMP_NOBREAK.
- *  - TERMP_HANG: Like TERMP_DANGLE, and also suppress padding before
- *    the next chunk if this column is not full.
+ *  - TERMP_NOPAD: Start writing at the current position,
+ *    do not pad with blank characters up to the offset.
  */
 void
 term_flushln(struct termp *p)
 {
-       size_t           i;     /* current input position in p->buf */
-       int              ntab;  /* number of tabs to prepend */
        size_t           vis;   /* current visual position on output */
        size_t           vbl;   /* number of blanks to prepend to output */
        size_t           vend;  /* end of word visual position on output */
        size_t           bp;    /* visual right border position */
        size_t           dv;    /* temporary for visual pos calculations */
-       size_t           j;     /* temporary loop index for p->buf */
+       size_t           j;     /* temporary loop index for p->tcol->buf */
        size_t           jhy;   /* last hyph before overflow w/r/t j */
        size_t           maxvis; /* output position of visible boundary */
-       size_t           rmargin; /* the rightmost of the two margins */
-
-       /*
-        * First, establish the maximum columns of "visible" content.
-        * This is usually the difference between the right-margin and
-        * an indentation, but can be, for tagged lists or columns, a
-        * small set of values.
-        *
-        * The following unsigned-signed subtractions look strange,
-        * but they are actually correct.  If the int p->overstep
-        * is negative, it gets sign extended.  Subtracting that
-        * very large size_t effectively adds a small number to dv.
-        */
-       rmargin = p->rmargin > p->offset ? p->rmargin : p->offset;
-       dv = p->rmargin - p->offset;
-       maxvis = (int)dv > p->overstep ? dv - (size_t)p->overstep : 0;
-
-       if (p->flags & TERMP_NOBREAK) {
-               dv = p->maxrmargin > p->offset ?
-                    p->maxrmargin - p->offset : 0;
-               bp = (int)dv > p->overstep ?
-                    dv - (size_t)p->overstep : 0;
-       } else
-               bp = maxvis;
-
-       /*
-        * Calculate the required amount of padding.
-        */
-       vbl = p->offset + p->overstep > p->viscol ?
-             p->offset + p->overstep - p->viscol : 0;
+       int              ntab;  /* number of tabs to prepend */
 
+       vbl = (p->flags & TERMP_NOPAD) || p->tcol->offset < p->viscol ?
+           0 : p->tcol->offset - p->viscol;
+       if (p->minbl && vbl < p->minbl)
+               vbl = p->minbl;
+       maxvis = p->tcol->rmargin > p->viscol + vbl ?
+           p->tcol->rmargin - p->viscol - vbl : 0;
+       bp = !(p->flags & TERMP_NOBREAK) ? maxvis :
+           p->maxrmargin > p->viscol + vbl ?
+           p->maxrmargin - p->viscol - vbl : 0;
        vis = vend = 0;
-       i = 0;
 
-       while (i < p->col) {
+       if (p->lasttcol == 0)
+               p->tcol->col = 0;
+       while (p->tcol->col < p->lastcol) {
+
                /*
                 * Handle literal tab characters: collapse all
                 * subsequent tabs into a single huge set of spaces.
                 */
+
                ntab = 0;
-               while (i < p->col && '\t' == p->buf[i]) {
-                       vend = (vis / p->tabwidth + 1) * p->tabwidth;
+               while (p->tcol->col < p->lastcol &&
+                   p->tcol->buf[p->tcol->col] == '\t') {
+                       vend = term_tab_next(vis);
                        vbl += vend - vis;
                        vis = vend;
                        ntab++;
-                       i++;
+                       p->tcol->col++;
                }
 
                /*
@@ -155,83 +142,90 @@ term_flushln(struct termp *p)
                 * space is printed according to regular spacing rules).
                 */
 
-               for (j = i, jhy = 0; j < p->col; j++) {
-                       if (' ' == p->buf[j] || '\t' == p->buf[j])
+               jhy = 0;
+               for (j = p->tcol->col; j < p->lastcol; j++) {
+                       if (p->tcol->buf[j] == ' ' || p->tcol->buf[j] == '\t')
                                break;
 
-                       /* Back over the the last printed character. */
-                       if (8 == p->buf[j]) {
+                       /* Back over the last printed character. */
+                       if (p->tcol->buf[j] == '\b') {
                                assert(j);
-                               vend -= (*p->width)(p, p->buf[j - 1]);
+                               vend -= (*p->width)(p, p->tcol->buf[j - 1]);
                                continue;
                        }
 
                        /* Regular word. */
                        /* Break at the hyphen point if we overrun. */
                        if (vend > vis && vend < bp &&
-                           (ASCII_HYPH == p->buf[j] ||
-                            ASCII_BREAK == p->buf[j]))
+                           (p->tcol->buf[j] == ASCII_HYPH||
+                            p->tcol->buf[j] == ASCII_BREAK))
                                jhy = j;
 
                        /*
                         * Hyphenation now decided, put back a real
                         * hyphen such that we get the correct width.
                         */
-                       if (ASCII_HYPH == p->buf[j])
-                               p->buf[j] = '-';
+                       if (p->tcol->buf[j] == ASCII_HYPH)
+                               p->tcol->buf[j] = '-';
 
-                       vend += (*p->width)(p, p->buf[j]);
+                       vend += (*p->width)(p, p->tcol->buf[j]);
                }
 
                /*
                 * Find out whether we would exceed the right margin.
                 * If so, break to the next line.
                 */
-               if (vend > bp && 0 == jhy && vis > 0) {
+
+               if (vend > bp && jhy == 0 && vis > 0 &&
+                   (p->flags & TERMP_BRNEVER) == 0) {
+                       if (p->lasttcol)
+                               return;
+
+                       endline(p);
                        vend -= vis;
-                       (*p->endline)(p);
-                       p->viscol = 0;
-                       if (TERMP_BRIND & p->flags) {
-                               vbl = rmargin;
-                               vend += rmargin - p->offset;
-                       } else
-                               vbl = p->offset;
 
-                       /* use pending tabs on the new line */
+                       /* Use pending tabs on the new line. */
 
-                       if (0 < ntab)
-                               vbl += ntab * p->tabwidth;
+                       vbl = 0;
+                       while (ntab--)
+                               vbl = term_tab_next(vbl);
 
-                       /*
-                        * Remove the p->overstep width.
-                        * Again, if p->overstep is negative,
-                        * sign extension does the right thing.
-                        */
+                       /* Re-establish indentation. */
 
-                       bp += (size_t)p->overstep;
-                       p->overstep = 0;
+                       if (p->flags & TERMP_BRIND)
+                               vbl += p->tcol->rmargin;
+                       else
+                               vbl += p->tcol->offset;
+                       maxvis = p->tcol->rmargin > vbl ?
+                           p->tcol->rmargin - vbl : 0;
+                       bp = !(p->flags & TERMP_NOBREAK) ? maxvis :
+                           p->maxrmargin > vbl ?  p->maxrmargin - vbl : 0;
                }
 
-               /* Write out the [remaining] word. */
-               for ( ; i < p->col; i++) {
-                       if (vend > bp && jhy > 0 && i > jhy)
+               /*
+                * Write out the rest of the word.
+                */
+
+               for ( ; p->tcol->col < p->lastcol; p->tcol->col++) {
+                       if (vend > bp && jhy > 0 && p->tcol->col > jhy)
                                break;
-                       if ('\t' == p->buf[i])
+                       if (p->tcol->buf[p->tcol->col] == '\t')
                                break;
-                       if (' ' == p->buf[i]) {
-                               j = i;
-                               while (i < p->col && ' ' == p->buf[i])
-                                       i++;
-                               dv = (i - j) * (*p->width)(p, ' ');
+                       if (p->tcol->buf[p->tcol->col] == ' ') {
+                               j = p->tcol->col;
+                               while (p->tcol->col < p->lastcol &&
+                                   p->tcol->buf[p->tcol->col] == ' ')
+                                       p->tcol->col++;
+                               dv = (p->tcol->col - j) * (*p->width)(p, ' ');
                                vbl += dv;
                                vend += dv;
                                break;
                        }
-                       if (ASCII_NBRSP == p->buf[i]) {
+                       if (p->tcol->buf[p->tcol->col] == ASCII_NBRSP) {
                                vbl += (*p->width)(p, ' ');
                                continue;
                        }
-                       if (ASCII_BREAK == p->buf[i])
+                       if (p->tcol->buf[p->tcol->col] == ASCII_BREAK)
                                continue;
 
                        /*
@@ -245,11 +239,13 @@ term_flushln(struct termp *p)
                                vbl = 0;
                        }
 
-                       (*p->letter)(p, p->buf[i]);
-                       if (8 == p->buf[i])
-                               p->viscol -= (*p->width)(p, p->buf[i-1]);
+                       (*p->letter)(p, p->tcol->buf[p->tcol->col]);
+                       if (p->tcol->buf[p->tcol->col] == '\b')
+                               p->viscol -= (*p->width)(p,
+                                   p->tcol->buf[p->tcol->col - 1]);
                        else
-                               p->viscol += (*p->width)(p, p->buf[i]);
+                               p->viscol += (*p->width)(p,
+                                   p->tcol->buf[p->tcol->col]);
                }
                vis = vend;
        }
@@ -258,43 +254,45 @@ term_flushln(struct termp *p)
         * If there was trailing white space, it was not printed;
         * so reset the cursor position accordingly.
         */
+
        if (vis > vbl)
                vis -= vbl;
        else
                vis = 0;
 
-       p->col = 0;
-       p->overstep = 0;
+       p->col = p->lastcol = 0;
+       p->minbl = p->trailspace;
+       p->flags &= ~(TERMP_BACKAFTER | TERMP_BACKBEFORE | TERMP_NOPAD);
 
-       if ( ! (TERMP_NOBREAK & p->flags)) {
-               p->viscol = 0;
-               (*p->endline)(p);
-               return;
-       }
-
-       if (TERMP_HANG & p->flags) {
-               p->overstep = (int)(vis - maxvis +
-                   p->trailspace * (*p->width)(p, ' '));
+       /* Trailing whitespace is significant in some columns. */
 
-               /*
-                * If we have overstepped the margin, temporarily move
-                * it to the right and flag the rest of the line to be
-                * shorter.
-                * If there is a request to keep the columns together,
-                * allow negative overstep when the column is not full.
-                */
-               if (p->trailspace && p->overstep < 0)
-                       p->overstep = 0;
-               return;
-
-       } else if (TERMP_DANGLE & p->flags)
-               return;
+       if (vis && vbl && (TERMP_BRTRSP & p->flags))
+               vis += vbl;
 
        /* If the column was overrun, break the line. */
-       if (maxvis < vis + p->trailspace * (*p->width)(p, ' ')) {
-               (*p->endline)(p);
-               p->viscol = 0;
+       if ((p->flags & TERMP_NOBREAK) == 0 ||
+           ((p->flags & TERMP_HANG) == 0 &&
+            vis + p->trailspace * (*p->width)(p, ' ') > maxvis))
+               endline(p);
+}
+
+static void
+endline(struct termp *p)
+{
+       if ((p->flags & (TERMP_NEWMC | TERMP_ENDMC)) == TERMP_ENDMC) {
+               p->mc = NULL;
+               p->flags &= ~TERMP_ENDMC;
        }
+       if (p->mc != NULL) {
+               if (p->viscol && p->maxrmargin >= p->viscol)
+                       (*p->advance)(p, p->maxrmargin - p->viscol + 1);
+               p->flags |= TERMP_NOBUF | TERMP_NOSPACE;
+               term_word(p, p->mc);
+               p->flags &= ~(TERMP_NOBUF | TERMP_NEWMC);
+       }
+       p->viscol = 0;
+       p->minbl = 0;
+       (*p->endline)(p);
 }
 
 /*
@@ -307,7 +305,7 @@ term_newln(struct termp *p)
 {
 
        p->flags |= TERMP_NOSPACE;
-       if (p->col || p->viscol)
+       if (p->lastcol || p->viscol)
                term_flushln(p);
 }
 
@@ -323,12 +321,14 @@ term_vspace(struct termp *p)
 
        term_newln(p);
        p->viscol = 0;
+       p->minbl = 0;
        if (0 < p->skipvsp)
                p->skipvsp--;
        else
                (*p->endline)(p);
 }
 
+/* Swap current and previous font; for \fP and .ft P */
 void
 term_fontlast(struct termp *p)
 {
@@ -339,6 +339,7 @@ term_fontlast(struct termp *p)
        p->fontq[p->fonti] = f;
 }
 
+/* Set font, save current, discard previous; for \f, .ft, .B etc. */
 void
 term_fontrepl(struct termp *p, enum termfont f)
 {
@@ -347,38 +348,31 @@ term_fontrepl(struct termp *p, enum termfont f)
        p->fontq[p->fonti] = f;
 }
 
+/* Set font, save previous. */
 void
 term_fontpush(struct termp *p, enum termfont f)
 {
 
-       assert(p->fonti + 1 < 10);
        p->fontl = p->fontq[p->fonti];
-       p->fontq[++p->fonti] = f;
-}
-
-const void *
-term_fontq(struct termp *p)
-{
-
-       return(&p->fontq[p->fonti]);
-}
-
-enum termfont
-term_fonttop(struct termp *p)
-{
-
-       return(p->fontq[p->fonti]);
+       if (++p->fonti == p->fontsz) {
+               p->fontsz += 8;
+               p->fontq = mandoc_reallocarray(p->fontq,
+                   p->fontsz, sizeof(*p->fontq));
+       }
+       p->fontq[p->fonti] = f;
 }
 
+/* Flush to make the saved pointer current again. */
 void
-term_fontpopq(struct termp *p, const void *key)
+term_fontpopq(struct termp *p, int i)
 {
 
-       while (p->fonti >= 0 && key < (void *)(p->fontq + p->fonti))
-               p->fonti--;
-       assert(p->fonti >= 0);
+       assert(i >= 0);
+       if (p->fonti > i)
+               p->fonti = i;
 }
 
+/* Pop one font off the stack. */
 void
 term_fontpop(struct termp *p)
 {
@@ -395,37 +389,34 @@ term_fontpop(struct termp *p)
 void
 term_word(struct termp *p, const char *word)
 {
+       struct roffsu    su;
        const char       nbrsp[2] = { ASCII_NBRSP, 0 };
        const char      *seq, *cp;
        int              sz, uc;
-       size_t           ssz;
+       size_t           csz, lsz, ssz;
        enum mandoc_esc  esc;
 
-       if ( ! (TERMP_NOSPACE & p->flags)) {
-               if ( ! (TERMP_KEEP & p->flags)) {
-                       bufferc(p, ' ');
-                       if (TERMP_SENTENCE & p->flags)
+       if ((p->flags & TERMP_NOBUF) == 0) {
+               if ((p->flags & TERMP_NOSPACE) == 0) {
+                       if ((p->flags & TERMP_KEEP) == 0) {
                                bufferc(p, ' ');
-               } else
-                       bufferc(p, ASCII_NBRSP);
+                               if (p->flags & TERMP_SENTENCE)
+                                       bufferc(p, ' ');
+                       } else
+                               bufferc(p, ASCII_NBRSP);
+               }
+               if (p->flags & TERMP_PREKEEP)
+                       p->flags |= TERMP_KEEP;
+               if (p->flags & TERMP_NONOSPACE)
+                       p->flags |= TERMP_NOSPACE;
+               else
+                       p->flags &= ~TERMP_NOSPACE;
+               p->flags &= ~(TERMP_SENTENCE | TERMP_NONEWLINE);
+               p->skipvsp = 0;
        }
-       if (TERMP_PREKEEP & p->flags)
-               p->flags |= TERMP_KEEP;
-
-       if ( ! (p->flags & TERMP_NONOSPACE))
-               p->flags &= ~TERMP_NOSPACE;
-       else
-               p->flags |= TERMP_NOSPACE;
-
-       p->flags &= ~(TERMP_SENTENCE | TERMP_NONEWLINE);
 
        while ('\0' != *word) {
                if ('\\' != *word) {
-                       if (TERMP_SKIPCHAR & p->flags) {
-                               p->flags &= ~TERMP_SKIPCHAR;
-                               word++;
-                               continue;
-                       }
                        if (TERMP_NBRWORD & p->flags) {
                                if (' ' == *word) {
                                        encode(p, nbrsp, 1);
@@ -456,12 +447,11 @@ term_word(struct termp *p, const char *word)
                        break;
                case ESCAPE_SPECIAL:
                        if (p->enc == TERMENC_ASCII) {
-                               cp = mchars_spec2str(p->symtab,
-                                   seq, sz, &ssz);
+                               cp = mchars_spec2str(seq, sz, &ssz);
                                if (cp != NULL)
                                        encode(p, cp, ssz);
                        } else {
-                               uc = mchars_spec2cp(p->symtab, seq, sz);
+                               uc = mchars_spec2cp(seq, sz);
                                if (uc > 0)
                                        encode1(p, uc);
                        }
@@ -476,7 +466,6 @@ term_word(struct termp *p, const char *word)
                        term_fontrepl(p, TERMFONT_BI);
                        continue;
                case ESCAPE_FONT:
-                       /* FALLTHROUGH */
                case ESCAPE_FONTROMAN:
                        term_fontrepl(p, TERMFONT_NONE);
                        continue;
@@ -484,13 +473,104 @@ term_word(struct termp *p, const char *word)
                        term_fontlast(p);
                        continue;
                case ESCAPE_NOSPACE:
-                       if (TERMP_SKIPCHAR & p->flags)
-                               p->flags &= ~TERMP_SKIPCHAR;
-                       else if ('\0' == *word)
+                       if (p->flags & TERMP_BACKAFTER)
+                               p->flags &= ~TERMP_BACKAFTER;
+                       else if (*word == '\0')
                                p->flags |= (TERMP_NOSPACE | TERMP_NONEWLINE);
                        continue;
+               case ESCAPE_HORIZ:
+                       if (a2roffsu(seq, &su, SCALE_EM) == NULL)
+                               continue;
+                       uc = term_hspan(p, &su) / 24;
+                       if (uc > 0)
+                               while (uc-- > 0)
+                                       bufferc(p, ASCII_NBRSP);
+                       else if (p->col > (size_t)(-uc))
+                               p->col += uc;
+                       else {
+                               uc += p->col;
+                               p->col = 0;
+                               if (p->tcol->offset > (size_t)(-uc)) {
+                                       p->ti += uc;
+                                       p->tcol->offset += uc;
+                               } else {
+                                       p->ti -= p->tcol->offset;
+                                       p->tcol->offset = 0;
+                               }
+                       }
+                       continue;
+               case ESCAPE_HLINE:
+                       if ((seq = a2roffsu(seq, &su, SCALE_EM)) == NULL)
+                               continue;
+                       uc = term_hspan(p, &su) / 24;
+                       if (uc <= 0) {
+                               if (p->tcol->rmargin <= p->tcol->offset)
+                                       continue;
+                               lsz = p->tcol->rmargin - p->tcol->offset;
+                       } else
+                               lsz = uc;
+                       if (*seq == '\0')
+                               uc = -1;
+                       else if (*seq == '\\') {
+                               seq++;
+                               esc = mandoc_escape(&seq, &cp, &sz);
+                               switch (esc) {
+                               case ESCAPE_UNICODE:
+                                       uc = mchars_num2uc(cp + 1, sz - 1);
+                                       break;
+                               case ESCAPE_NUMBERED:
+                                       uc = mchars_num2char(cp, sz);
+                                       break;
+                               case ESCAPE_SPECIAL:
+                                       uc = mchars_spec2cp(cp, sz);
+                                       break;
+                               default:
+                                       uc = -1;
+                                       break;
+                               }
+                       } else
+                               uc = *seq;
+                       if (uc < 0x20 || (uc > 0x7E && uc < 0xA0))
+                               uc = '_';
+                       if (p->enc == TERMENC_ASCII) {
+                               cp = ascii_uc2str(uc);
+                               csz = term_strlen(p, cp);
+                               ssz = strlen(cp);
+                       } else
+                               csz = (*p->width)(p, uc);
+                       while (lsz >= csz) {
+                               if (p->enc == TERMENC_ASCII)
+                                       encode(p, cp, ssz);
+                               else
+                                       encode1(p, uc);
+                               lsz -= csz;
+                       }
+                       continue;
                case ESCAPE_SKIPCHAR:
-                       p->flags |= TERMP_SKIPCHAR;
+                       p->flags |= TERMP_BACKAFTER;
+                       continue;
+               case ESCAPE_OVERSTRIKE:
+                       cp = seq + sz;
+                       while (seq < cp) {
+                               if (*seq == '\\') {
+                                       mandoc_escape(&seq, NULL, NULL);
+                                       continue;
+                               }
+                               encode1(p, *seq++);
+                               if (seq < cp) {
+                                       if (p->flags & TERMP_BACKBEFORE)
+                                               p->flags |= TERMP_BACKAFTER;
+                                       else
+                                               p->flags |= TERMP_BACKBEFORE;
+                               }
+                       }
+                       /* Trim trailing backspace/blank pair. */
+                       if (p->lastcol > 2 &&
+                           (p->tcol->buf[p->lastcol - 1] == ' ' ||
+                            p->tcol->buf[p->lastcol - 1] == '\t'))
+                               p->lastcol -= 2;
+                       if (p->col > p->lastcol)
+                               p->col = p->lastcol;
                        continue;
                default:
                        continue;
@@ -515,25 +595,28 @@ term_word(struct termp *p, const char *word)
 }
 
 static void
-adjbuf(struct termp *p, size_t sz)
+adjbuf(struct termp_col *c, size_t sz)
 {
-
-       if (0 == p->maxcols)
-               p->maxcols = 1024;
-       while (sz >= p->maxcols)
-               p->maxcols <<= 2;
-
-       p->buf = mandoc_reallocarray(p->buf, p->maxcols, sizeof(int));
+       if (c->maxcols == 0)
+               c->maxcols = 1024;
+       while (c->maxcols <= sz)
+               c->maxcols <<= 2;
+       c->buf = mandoc_reallocarray(c->buf, c->maxcols, sizeof(*c->buf));
 }
 
 static void
 bufferc(struct termp *p, char c)
 {
-
-       if (p->col + 1 >= p->maxcols)
-               adjbuf(p, p->col + 1);
-
-       p->buf[p->col++] = c;
+       if (p->flags & TERMP_NOBUF) {
+               (*p->letter)(p, c);
+               return;
+       }
+       if (p->col + 1 >= p->tcol->maxcols)
+               adjbuf(p->tcol, p->col + 1);
+       if (p->lastcol <= p->col || (c != ' ' && c != ASCII_NBRSP))
+               p->tcol->buf[p->col] = c;
+       if (p->lastcol < ++p->col)
+               p->lastcol = p->col;
 }
 
 /*
@@ -546,28 +629,44 @@ encode1(struct termp *p, int c)
 {
        enum termfont     f;
 
-       if (TERMP_SKIPCHAR & p->flags) {
-               p->flags &= ~TERMP_SKIPCHAR;
+       if (p->flags & TERMP_NOBUF) {
+               (*p->letter)(p, c);
                return;
        }
 
-       if (p->col + 6 >= p->maxcols)
-               adjbuf(p, p->col + 6);
+       if (p->col + 7 >= p->tcol->maxcols)
+               adjbuf(p->tcol, p->col + 7);
 
-       f = term_fonttop(p);
+       f = (c == ASCII_HYPH || c > 127 || isgraph(c)) ?
+           p->fontq[p->fonti] : TERMFONT_NONE;
 
-       if (TERMFONT_UNDER == f || TERMFONT_BI == f) {
-               p->buf[p->col++] = '_';
-               p->buf[p->col++] = 8;
+       if (p->flags & TERMP_BACKBEFORE) {
+               if (p->tcol->buf[p->col - 1] == ' ' ||
+                   p->tcol->buf[p->col - 1] == '\t')
+                       p->col--;
+               else
+                       p->tcol->buf[p->col++] = '\b';
+               p->flags &= ~TERMP_BACKBEFORE;
+       }
+       if (f == TERMFONT_UNDER || f == TERMFONT_BI) {
+               p->tcol->buf[p->col++] = '_';
+               p->tcol->buf[p->col++] = '\b';
        }
-       if (TERMFONT_BOLD == f || TERMFONT_BI == f) {
-               if (ASCII_HYPH == c)
-                       p->buf[p->col++] = '-';
+       if (f == TERMFONT_BOLD || f == TERMFONT_BI) {
+               if (c == ASCII_HYPH)
+                       p->tcol->buf[p->col++] = '-';
                else
-                       p->buf[p->col++] = c;
-               p->buf[p->col++] = 8;
+                       p->tcol->buf[p->col++] = c;
+               p->tcol->buf[p->col++] = '\b';
+       }
+       if (p->lastcol <= p->col || (c != ' ' && c != ASCII_NBRSP))
+               p->tcol->buf[p->col] = c;
+       if (p->lastcol < ++p->col)
+               p->lastcol = p->col;
+       if (p->flags & TERMP_BACKAFTER) {
+               p->flags |= TERMP_BACKBEFORE;
+               p->flags &= ~TERMP_BACKAFTER;
        }
-       p->buf[p->col++] = c;
 }
 
 static void
@@ -575,45 +674,46 @@ encode(struct termp *p, const char *word, size_t sz)
 {
        size_t            i;
 
-       if (TERMP_SKIPCHAR & p->flags) {
-               p->flags &= ~TERMP_SKIPCHAR;
-               return;
-       }
-
-       /*
-        * Encode and buffer a string of characters.  If the current
-        * font mode is unset, buffer directly, else encode then buffer
-        * character by character.
-        */
-
-       if (TERMFONT_NONE == term_fonttop(p)) {
-               if (p->col + sz >= p->maxcols)
-                       adjbuf(p, p->col + sz);
+       if (p->flags & TERMP_NOBUF) {
                for (i = 0; i < sz; i++)
-                       p->buf[p->col++] = word[i];
+                       (*p->letter)(p, word[i]);
                return;
        }
 
-       /* Pre-buffer, assuming worst-case. */
-
-       if (p->col + 1 + (sz * 5) >= p->maxcols)
-               adjbuf(p, p->col + 1 + (sz * 5));
+       if (p->col + 2 + (sz * 5) >= p->tcol->maxcols)
+               adjbuf(p->tcol, p->col + 2 + (sz * 5));
 
        for (i = 0; i < sz; i++) {
                if (ASCII_HYPH == word[i] ||
                    isgraph((unsigned char)word[i]))
                        encode1(p, word[i]);
-               else
-                       p->buf[p->col++] = word[i];
+               else {
+                       if (p->lastcol <= p->col ||
+                           (word[i] != ' ' && word[i] != ASCII_NBRSP))
+                               p->tcol->buf[p->col] = word[i];
+                       p->col++;
+
+                       /*
+                        * Postpone the effect of \z while handling
+                        * an overstrike sequence from ascii_uc2str().
+                        */
+
+                       if (word[i] == '\b' &&
+                           (p->flags & TERMP_BACKBEFORE)) {
+                               p->flags &= ~TERMP_BACKBEFORE;
+                               p->flags |= TERMP_BACKAFTER;
+                       }
+               }
        }
+       if (p->lastcol < p->col)
+               p->lastcol = p->col;
 }
 
 void
 term_setwidth(struct termp *p, const char *wstr)
 {
        struct roffsu    su;
-       size_t           width;
-       int              iop;
+       int              iop, width;
 
        iop = 0;
        width = 0;
@@ -630,7 +730,7 @@ term_setwidth(struct termp *p, const char *wstr)
                default:
                        break;
                }
-               if (a2roffsu(wstr, &su, SCALE_MAX))
+               if (a2roffsu(wstr, &su, SCALE_MAX) != NULL)
                        width = term_hspan(p, &su);
                else
                        iop = 0;
@@ -642,7 +742,7 @@ size_t
 term_len(const struct termp *p, size_t sz)
 {
 
-       return((*p->width)(p, ' ') * sz);
+       return (*p->width)(p, ' ') * sz;
 }
 
 static size_t
@@ -651,9 +751,9 @@ cond_width(const struct termp *p, int c, int *skip)
 
        if (*skip) {
                (*skip) = 0;
-               return(0);
+               return 0;
        } else
-               return((*p->width)(p, c));
+               return (*p->width)(p, c);
 }
 
 size_t
@@ -699,13 +799,11 @@ term_strlen(const struct termp *p, const char *cp)
                                break;
                        case ESCAPE_SPECIAL:
                                if (p->enc == TERMENC_ASCII) {
-                                       rhs = mchars_spec2str(p->symtab,
-                                           seq, ssz, &rsz);
+                                       rhs = mchars_spec2str(seq, ssz, &rsz);
                                        if (rhs != NULL)
                                                break;
                                } else {
-                                       uc = mchars_spec2cp(p->symtab,
-                                           seq, ssz);
+                                       uc = mchars_spec2cp(seq, ssz);
                                        if (uc > 0)
                                                sz += cond_width(p, uc, &skip);
                                }
@@ -713,6 +811,20 @@ term_strlen(const struct termp *p, const char *cp)
                        case ESCAPE_SKIPCHAR:
                                skip = 1;
                                continue;
+                       case ESCAPE_OVERSTRIKE:
+                               rsz = 0;
+                               rhs = seq + ssz;
+                               while (seq < rhs) {
+                                       if (*seq == '\\') {
+                                               mandoc_escape(&seq, NULL, NULL);
+                                               continue;
+                                       }
+                                       i = (*p->width)(p, *seq++);
+                                       if (rsz < i)
+                                               rsz = i;
+                               }
+                               sz += rsz;
+                               continue;
                        default:
                                continue;
                        }
@@ -755,58 +867,63 @@ term_strlen(const struct termp *p, const char *cp)
                case ASCII_HYPH:
                        sz += cond_width(p, '-', &skip);
                        cp++;
-                       /* FALLTHROUGH */
-               case ASCII_BREAK:
                        break;
                default:
                        break;
                }
        }
 
-       return(sz);
+       return sz;
 }
 
-size_t
+int
 term_vspan(const struct termp *p, const struct roffsu *su)
 {
        double           r;
+       int              ri;
 
        switch (su->unit) {
+       case SCALE_BU:
+               r = su->scale / 40.0;
+               break;
        case SCALE_CM:
-               r = su->scale * 2.0;
+               r = su->scale * 6.0 / 2.54;
+               break;
+       case SCALE_FS:
+               r = su->scale * 65536.0 / 40.0;
                break;
        case SCALE_IN:
                r = su->scale * 6.0;
                break;
+       case SCALE_MM:
+               r = su->scale * 0.006;
+               break;
        case SCALE_PC:
                r = su->scale;
                break;
        case SCALE_PT:
-               r = su->scale / 8.0;
+               r = su->scale / 12.0;
                break;
-       case SCALE_MM:
-               r = su->scale / 1000.0;
+       case SCALE_EN:
+       case SCALE_EM:
+               r = su->scale * 0.6;
                break;
        case SCALE_VS:
                r = su->scale;
                break;
        default:
-               r = su->scale - 1.0;
-               break;
+               abort();
        }
-
-       if (r < 0.0)
-               r = 0.0;
-       return((size_t)(r + 0.0005));
+       ri = r > 0.0 ? r + 0.4995 : r - 0.4995;
+       return ri < 66 ? ri : 1;
 }
 
-size_t
+/*
+ * Convert a scaling width to basic units, rounding down.
+ */
+int
 term_hspan(const struct termp *p, const struct roffsu *su)
 {
-       double           v;
 
-       v = (*p->hspan)(p, su);
-       if (v < 0.0)
-               v = 0.0;
-       return((size_t)(v + 0.0005));
+       return (*p->hspan)(p, su);
 }