When checking cross references with -Tlint, ultimately fall back to

looking in the current working directory.  Not a security issue
because the files are never open(2)ed, only access(2)ed.
Requested by jmc@ and inspired by mdoclint(1).

This cannot be perfect because it only works for files having the
exact filename ./pagename.sec - mandoc has no way to figure out
which files might contain a manual for multiple names, or that files
in autohell might be called ./pagename.man.in instead, or which
subdirectories might contain additional source files.  Also, it may
hide messages if you have bogus stuff lying around in the directory
where you run mandoc -Tlint.  But jmc@ considers it important, and
good enough for everyday use.

Also avoid leaking the memory for the file name while here.

diff --git a/main.c b/main.c
index efee75386a1f84ea05b2b6179844f59074370662..df0cdabee1ba075bbe8d886076e1eeea600b23a4 100644 (file)
--- a/main.c
+++ b/main.c
@@ -1,4 +1,4 @@
-/*     $Id: main.c,v 1.295 2017/07/01 12:02:31 schwarze Exp $ */
+/*     $Id: main.c,v 1.296 2017/07/01 12:54:07 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2012, 2014-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -663,14 +663,23 @@ fs_lookup(const struct manpaths *paths, size_t ipath,
        if (globres == 0)
                file = mandoc_strdup(*globinfo.gl_pathv);
        globfree(&globinfo);
-       if (globres != 0)
+       if (globres == 0)
+               goto found;
+       if (res != NULL || ipath + 1 != paths->sz)
                return 0;
 
+       mandoc_asprintf(&file, "%s.%s", name, sec);
+       globres = access(file, R_OK);
+       free(file);
+       return globres != -1;
+
 found:
        warnx("outdated mandoc.db lacks %s(%s) entry, run %s %s",
            name, sec, BINM_MAKEWHATIS, paths->paths[ipath]);
-       if (res == NULL)
+       if (res == NULL) {
+               free(file);
                return 1;
+       }
        *res = mandoc_reallocarray(*res, ++*ressz, sizeof(struct manpage));
        page = *res + (*ressz - 1);
        page->file = file;