diff options
author | Ingo Schwarze <schwarze@openbsd.org> | 2022-08-15 18:12:30 +0000 |
---|---|---|
committer | Ingo Schwarze <schwarze@openbsd.org> | 2022-08-15 18:12:30 +0000 |
commit | 6ecd9c5caba944d910343802c058940234492e5a (patch) | |
tree | 6fe94640b4da8a1edda86aa430d5214b2eb33c59 /term.c | |
parent | ffa876e5886e09f94c3fe78fbef3cc7ebcd8a611 (diff) | |
download | mandoc-6ecd9c5caba944d910343802c058940234492e5a.tar.gz |
Distinguish between escape sequences that produce no output
whatsoever (for example \fR) and escape sequences that produce
invisible zero-width output (for example \&). No, i'm not joking,
groff does make that distinction, and it has consequences in some
situations, for example for vertical spacing in no-fill mode.
Heirloom and Plan 9 behaviour is subtly different, but in case of
doubt, we want to follow groff.
While this fixes the behaviour for the majority of escape sequences,
in particular for those most likely to occur in practice, it is not
perfect yet because some of the more exotic ESCAPE_IGNORE sequences
are actually of the "no output whatsoever" type but treated
as "invisible zero-width" for now. With the new ASCII_NBRZW mechanism
in place, switching them over one by one when the need arises will
no longer be very difficult.
Diffstat (limited to 'term.c')
-rw-r--r-- | term.c | 22 |
1 files changed, 16 insertions, 6 deletions
@@ -208,7 +208,6 @@ term_flushln(struct termp *p) return; endline(p); - p->viscol = 0; /* * Normally, start the next line at the same indentation @@ -314,6 +313,8 @@ term_fill(struct termp *p, size_t *nbr, size_t *vbr, size_t vtarget) vis = term_tab_next(vis); vis -= p->tcol->taboff; break; + case ASCII_NBRZW: /* Non-breakable zero-width. */ + break; case ASCII_NBRSP: /* Non-breakable space. */ p->tcol->buf[ic] = ' '; /* FALLTHROUGH */ @@ -365,6 +366,7 @@ term_field(struct termp *p, size_t vbl, size_t nbr) switch (p->tcol->buf[ic]) { case '\n': case ASCII_BREAK: + case ASCII_NBRZW: continue; case '\t': case ' ': @@ -571,18 +573,23 @@ term_word(struct termp *p, const char *word) break; case ESCAPE_NUMBERED: uc = mchars_num2char(seq, sz); - if (uc < 0) - continue; - break; + if (uc >= 0) + break; + bufferc(p, ASCII_NBRZW); + continue; case ESCAPE_SPECIAL: if (p->enc == TERMENC_ASCII) { cp = mchars_spec2str(seq, sz, &ssz); if (cp != NULL) encode(p, cp, ssz); + else + bufferc(p, ASCII_NBRZW); } else { uc = mchars_spec2cp(seq, sz); if (uc > 0) encode1(p, uc); + else + bufferc(p, ASCII_NBRZW); } continue; case ESCAPE_UNDEF: @@ -744,6 +751,9 @@ term_word(struct termp *p, const char *word) if (p->col > p->tcol->lastcol) p->col = p->tcol->lastcol; continue; + case ESCAPE_IGNORE: + bufferc(p, ASCII_NBRZW); + continue; default: continue; } @@ -935,8 +945,8 @@ term_strlen(const struct termp *p, const char *cp) int ssz, skip, uc; const char *seq, *rhs; enum mandoc_esc esc; - static const char rej[] = { '\\', ASCII_NBRSP, ASCII_HYPH, - ASCII_BREAK, '\0' }; + static const char rej[] = { '\\', ASCII_NBRSP, ASCII_NBRZW, + ASCII_BREAK, ASCII_HYPH, '\0' }; /* * Account for escaped sequences within string length |