fix: do not call addChannelfor 2 merged branches configured with the same channel

lib/branches/normalize.js

@@ -1,4 +1,4 @@
-const {sortBy} = require('lodash');
+const {sortBy, isNil} = require('lodash');
 const semver = require('semver');
 const semverDiff = require('semver-diff');
 const {FIRST_RELEASE, RELEASE_TYPE} = require('../definitions/constants');
@@ -20,7 +20,7 @@ function maintenance({maintenance, release}) {
       ...rest,
       name,
       range: range || name,
-      channel: channel || name,
+      channel: isNil(channel) ? name : channel,
     })),
     'range'
   ).map(({name, range, tags, ...rest}, idx, branches) => {
@@ -83,7 +83,7 @@ function release({release}) {
     const diff = bound ? semverDiff(min, bound) : null;
     return {
       ...rest,
-      channel: idx === 0 ? channel : channel || name,
+      channel: idx === 0 ? channel : isNil(channel) ? name : channel,
       tags,
       type: 'release',
       name,
@@ -98,7 +98,7 @@ function prerelease({prerelease}) {
     const preid = prerelease === true ? name : prerelease;
     return {
       ...rest,
-      channel: channel || name,
+      channel: isNil(channel) ? name : channel,
       type: 'prerelease',
       name,
       prerelease: preid,