Fix default bw weights with new consensus method

See #14881

changes/14881

@@ -0,0 +1,4 @@
+  o Minor bugfixes (consensus weight):
+    - Add new consensus method that initializes bw weights to 1 instead of 0. This
+      prevents a zero weight from making it all the way to the end (happens in
+      small testing networks) and causing an error. Fixes bug 14881.

src/or/dirvote.c

@@ -1367,6 +1367,11 @@ networkstatus_compute_consensus(smartlist_t *votes,
     consensus_method = MAX_SUPPORTED_CONSENSUS_METHOD;
   }
 
+  if (consensus_method >= MIN_METHOD_FOR_INIT_BW_WEIGHTS_ONE) {
+    G = M = E = D = 1;
+    T = 4;
+  }
+
   /* Compute medians of time-related things, and figure out how many
    * routers we might need to talk about. */
   {

src/or/dirvote.h

@@ -55,7 +55,7 @@
 #define MIN_SUPPORTED_CONSENSUS_METHOD 13
 
 /** The highest consensus method that we currently support. */
-#define MAX_SUPPORTED_CONSENSUS_METHOD 25
+#define MAX_SUPPORTED_CONSENSUS_METHOD 26
 
 /** Lowest consensus method where microdesc consensuses omit any entry
  * with no microdesc. */
@@ -111,6 +111,10 @@
  * entries. */
 #define MIN_METHOD_FOR_RS_PROTOCOLS 25
 
+/** Lowest consensus method where authorities initialize bandwidth weights to 1
+ * instead of 0. See #14881 */
+#define MIN_METHOD_FOR_INIT_BW_WEIGHTS_ONE 26
+
 /** Default bandwidth to clip unmeasured bandwidths to using method >=
  * MIN_METHOD_TO_CLIP_UNMEASURED_BW.  (This is not a consensus method; do not
  * get confused with the above macros.) */