bin/48438: mandoc(1) fails to handle nested double quote correctly.

[tsugutomo.enami%jp.sony.com@localhost]

>Number:         48438
>Category:       bin
>Synopsis:       mandoc(1) fails to handle nested double quote correctly.
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Dec 10 08:45:00 +0000 2013
>Originator:     enami tsugutomo
>Release:        NetBSD 6.1_STABLE
>Organization:
>Environment:
System: NetBSD sigtrap.sm.sony.co.jp 6.1_STABLE NetBSD 6.1_STABLE (GENERIC) 
#44: Mon Oct 21 17:13:31 JST 2013 
enami%sigtrap.sm.sony.co.jp@localhost:/home/enami/src/netbsd-6/obj.amd64/sys/arch/amd64/compile/GENERIC
 amd64
Architecture: x86_64
Machine: amd64
>Description:
mandoc(1) fails to handle nested double quote correctly.

>How-To-Repeat:

% cd /usr/src
% for c in 'nroff -mandoc' mandoc; do $c usr.bin/jot/jot.1; done | grep grep
           grep `jot -s "" -b . 80`
           grep `jot -s """" -b . 80`
%

The former is correct output by nroff -mandoc and the latter is incorrect
output by mandoc command.

>Fix:

Skip double qoute inside double quote like mandoc_getarg() does.

Index: dist/mdoc_argv.c
===================================================================
RCS file: /cvsroot/src/external/bsd/mdocml/dist/mdoc_argv.c,v
retrieving revision 1.4
diff -u -r1.4 mdoc_argv.c
--- dist/mdoc_argv.c    3 Apr 2013 14:50:26 -0000       1.4
+++ dist/mdoc_argv.c    10 Dec 2013 08:39:42 -0000
@@ -550,6 +550,7 @@
         */
 
        if (MDOC_PHRASELIT & m->flags || '\"' == buf[*pos]) {
+               int pairs = 0;
                if ( ! (MDOC_PHRASELIT & m->flags))
                        *v = &buf[++(*pos)];
 
@@ -557,11 +558,14 @@
                        m->flags |= MDOC_PHRASELIT;
 
                for ( ; buf[*pos]; (*pos)++) {
+                       if (pairs)
+                               buf[*pos - pairs] = buf[*pos];
                        if ('\"' != buf[*pos])
                                continue;
                        if ('\"' != buf[*pos + 1])
                                break;
                        (*pos)++;
+                       pairs++;
                }
 
                if ('\0' == buf[*pos]) {
@@ -572,7 +576,7 @@
                }
 
                m->flags &= ~MDOC_PHRASELIT;
-               buf[(*pos)++] = '\0';
+               buf[(*pos)++ - pairs] = '\0';
 
                if ('\0' == buf[*pos])
                        return(ARGS_QWORD);