man.cgi: clean exit when absent or empty manpath.conf

[Sébastien Marie]

Hi,

Starting to play with man.cgi (src/usr.bin/mandoc/cgi.c), it seems that
man.cgi will segfault if configuration file is absent or empty.

Here a patch that display error message and 505, like when MAN_DIR is
invalid.

Note: the segfault occurs in cgi.c:224 (http_parse), that assume
req->p is not NULL (req->q.manpath = req->p[0]).

The diff use the same style that when MAN_DIR is invalid (cgi.c:917), but that 
could
be improved using err(3) ?

Thanks.
-- 
Sébastien Marie


Index: cgi.c
===================================================================
RCS file: /cvs/src/usr.bin/mandoc/cgi.c,v
retrieving revision 1.13
diff -u -p -r1.13 cgi.c
--- cgi.c       13 Jul 2014 15:38:06 -0000      1.13
+++ cgi.c       18 Jul 2014 06:43:14 -0000
@@ -966,8 +968,12 @@ pathgen(struct req *req)
        char    *dp;
        size_t   dpsz;
 
-       if (NULL == (fp = fopen("manpath.conf", "r")))
-               return;
+       if (NULL == (fp = fopen("manpath.conf", "r"))) {
+               fprintf(stderr, "manpath.conf not found in MAN_DIR (%s)\n",
+                                                   MAN_DIR);
+               pg_error_internal();
+               exit(EXIT_FAILURE);
+       }
 
        while (NULL != (dp = fgetln(fp, &dpsz))) {
                if ('\n' == dp[dpsz - 1])
@@ -975,5 +981,11 @@ pathgen(struct req *req)
                req->p = mandoc_realloc(req->p,
                    (req->psz + 1) * sizeof(char *));
                req->p[req->psz++] = mandoc_strndup(dp, dpsz);
+       }
+
+       if ( req->p == NULL ) {
+               fprintf(stderr, "empty manpath.conf\n");
+               pg_error_internal();
+               exit(EXIT_FAILURE);
        }
 }