From 83628a48b5e0be3b992a89333999b5ee174a75c4 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Wed, 17 Oct 2018 19:17:06 -0700
Subject: [PATCH] tools: do not lint commit message if var undefined

Check that $TRAVIS_COMMIT_RANGE is set before trying to lint commit
messages in Travis CI.

Refs: https://github.com/nodejs/node/pull/23572#issuecomment-430850382
Refs: https://github.com/nodejs/node/pull/22842#issuecomment-430850049
---
 .travis.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index fad2e7f0c77509..156d28298b4e58 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,7 +13,7 @@ matrix:
       script:
         - make lint
         # Lint the first commit in the PR.
-        - git log $TRAVIS_COMMIT_RANGE --pretty=format:'%h' --no-merges | tail -1 | xargs npx core-validate-commit --no-validate-metadata
+        - \[ -z "$TRAVIS_COMMIT_RANGE" \] || git log $TRAVIS_COMMIT_RANGE --pretty=format:'%h' --no-merges | tail -1 | xargs npx core-validate-commit --no-validate-metadata
     - name: "Test Suite"
       install:
         - ./configure