[tor-commits] [tor/master] Routerset config parsing: represent empty sets as NULL.

[asn at torproject.org]

commit 2074fed6642713bcdfdc76f379956e97663ab8d0
Author: Nick Mathewson <nickm at torproject.org>
Date:   Wed Aug 28 11:51:16 2019 -0400

    Routerset config parsing: represent empty sets as NULL.
    
    routerset_t has two representations of an empty routerset: NULL, and
    a set containing no elements.  But some of our config code assumes
    that empty routersets are represented as NULL.  So let's give it
    what it assumes.
    
    Fixes bug 31495. Bugfix on e16b90b88a76; but not in any released
    Tor.
---
 src/feature/nodelist/routerset.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/feature/nodelist/routerset.c b/src/feature/nodelist/routerset.c
index 76777847e..12965ad0d 100644
--- a/src/feature/nodelist/routerset.c
+++ b/src/feature/nodelist/routerset.c
@@ -479,6 +479,10 @@ routerset_kv_parse(void *target, const config_line_t *line, char **errmsg,
     *errmsg = tor_strdup("Invalid router list.");
     return -1;
   } else {
+    if (routerset_is_empty(rs)) {
+      /* Represent empty sets as NULL. */
+      routerset_free(rs);
+    }
     *p = rs;
     return 0;
   }
@@ -507,8 +511,10 @@ routerset_copy(void *dest, const void *src, const void *params)
   routerset_t **output = (routerset_t**)dest;
   const routerset_t *input = *(routerset_t**)src;
   routerset_free(*output); // sets *output to NULL
-  *output = routerset_new();
-  routerset_union(*output, input);
+  if (! routerset_is_empty(input)) {
+    *output = routerset_new();
+    routerset_union(*output, input);
+  }
   return 0;
 }