1 files changed, 2 insertions, 3 deletions
diff --git a/scripts/environment.js b/scripts/environment.js
index 0468be3720..cb533a74a8 100755
--- a/scripts/environment.js
+++ b/scripts/environment.js
@@ -7,6 +7,7 @@ const github = require('@octokit/rest')();
 const {execSync} = require('child_process');
 
 const pr = process.env['CIRCLE_PULL_REQUEST'];
+const head = process.env['CIRCLE_SHA1'] || 'HEAD';
 if (pr) {
     const number = +pr.match(/\/(\d+)\/?$/)[1];
     return github.pullRequests.get({
@@ -15,17 +16,15 @@ if (pr) {
         number
     }).then(({data}) => {
         const base = data.base.ref;
-        const head = process.env['CIRCLE_SHA1'];
         const mergeBase = execSync(`git merge-base origin/${base} ${head}`).toString().trim();
 
         console.log(`export CIRCLE_TARGET_BRANCH=${base}`);
         console.log(`export CIRCLE_MERGE_BASE=${mergeBase}`);
     });
 } else {
-    const head = process.env['CIRCLE_SHA1'];
     for (const sha of execSync(`git rev-list --max-count=10 ${head}`).toString().trim().split('\n')) {
         const base = execSync(`git branch -r --contains ${sha} origin/master origin/release-*`).toString().split('\n')[0].trim().replace(/^origin\//, '');
-        if (base) {
+        if (base.match(/^(master|release-[a-z]+)$/)) {
             const mergeBase = execSync(`git merge-base origin/${base} ${head}`).toString().trim();
             console.log(`export CIRCLE_TARGET_BRANCH=${base}`);
             console.log(`export CIRCLE_MERGE_BASE=${mergeBase}`);