Reduce false positives for the "no blank before trailing delimiter" message.

This brings us down to one false positive for about every 18 pages.

diff --git a/usr.bin/mandoc/mdoc_validate.c b/usr.bin/mandoc/mdoc_validate.c
index ec5ff27..4fe4f25 100644 (file)
--- a/usr.bin/mandoc/mdoc_validate.c
+++ b/usr.bin/mandoc/mdoc_validate.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: mdoc_validate.c,v 1.248 2017/06/10 01:48:31 schwarze Exp $ */
+/*     $OpenBSD: mdoc_validate.c,v 1.249 2017/06/10 16:53:58 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -410,9 +410,17 @@ static void
 post_delim(POST_ARGS)
 {
        const struct roff_node  *nch;
-       const char              *lc;
+       const char              *lc, *cp;
+       int                      nw;
        enum mdelim              delim;
+       enum roff_tok            tok;
 
+       /*
+        * Find candidates: at least two bytes,
+        * the last one a closing or middle delimiter.
+        */
+
+       tok = mdoc->last->tok;
        nch = mdoc->last->last;
        if (nch == NULL || nch->type != ROFFT_TEXT)
                return;
@@ -422,9 +430,74 @@ post_delim(POST_ARGS)
        delim = mdoc_isdelim(lc);
        if (delim == DELIM_NONE || delim == DELIM_OPEN)
                return;
+
+       /*
+        * Reduce false positives by allowing various cases.
+        */
+
+       /* Escaped delimiters. */
+       if (lc > nch->string + 1 && lc[-2] == '\\' &&
+           (lc[-1] == '&' || lc[-1] == 'e'))
+               return;
+
+       /* Specific byte sequences. */
+       switch (*lc) {
+       case ')':
+               for (cp = lc; cp >= nch->string; cp--)
+                       if (*cp == '(')
+                               return;
+               break;
+       case '.':
+               if (lc > nch->string + 1 && lc[-2] == '.' && lc[-1] == '.')
+                       return;
+               if (lc[-1] == '.')
+                       return;
+               break;
+       case ';':
+               if (tok == MDOC_Vt)
+                       return;
+               break;
+       case '?':
+               if (lc[-1] == '?')
+                       return;
+               break;
+       case ']':
+               for (cp = lc; cp >= nch->string; cp--)
+                       if (*cp == '[')
+                               return;
+               break;
+       case '|':
+               if (lc == nch->string + 1 && lc[-1] == '|')
+                       return;
+       default:
+               break;
+       }
+
+       /* Exactly two non-alphanumeric bytes. */
+       if (lc == nch->string + 1 && !isalnum((unsigned char)lc[-1]))
+               return;
+
+       /* At least three alphabetic words with a sentence ending. */
+       if (strchr("!.:?", *lc) != NULL && (tok == MDOC_Em ||
+           tok == MDOC_Li || tok == MDOC_No || tok == MDOC_Po ||
+           tok == MDOC_Pq || tok == MDOC_Sy)) {
+               nw = 0;
+               for (cp = lc - 1; cp >= nch->string; cp--) {
+                       if (*cp == ' ') {
+                               nw++;
+                               if (cp > nch->string && cp[-1] == ',')
+                                       cp--;
+                       } else if (isalpha((unsigned int)*cp)) {
+                               if (nw > 1)
+                                       return;
+                       } else
+                               break;
+               }
+       }
+
        mandoc_vmsg(MANDOCERR_DELIM, mdoc->parse,
            nch->line, nch->pos + (lc - nch->string),
-           "%s%s %s", roff_name[mdoc->last->tok],
+           "%s%s %s", roff_name[tok],
            nch == mdoc->last->child ? "" : " ...", nch->string);
 }