From db1de759a9caed5f77b9b550ce0085833a1eb05b Mon Sep 17 00:00:00 2001
From: "Miss Islington (bot)"
 <31488909+miss-islington@users.noreply.github.com>
Date: Sun, 11 Feb 2018 14:21:32 -0800
Subject: [PATCH] Fix AppVeyor doc short-circuit (GH-5634)

(cherry picked from commit 6ea20fc719dcaf102d2cefa1786f0421514f7a58)
---
 .github/appveyor.yml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/.github/appveyor.yml b/.github/appveyor.yml
index 6e6a078a103267..e26969664ec29c 100644
--- a/.github/appveyor.yml
+++ b/.github/appveyor.yml
@@ -14,12 +14,15 @@ before_build:
       } elseif (!$env:APPVEYOR_PULL_REQUEST_HEAD_COMMIT) {
         echo 'Not a PR, doing full build.'
       } else {
-        $mergebase = git merge-base $env:APPVEYOR_PULL_REQUEST_HEAD_COMMIT $env:APPVEYOR_REPO_BRANCH
+        git fetch -q origin +refs/heads/$env:APPVEYOR_REPO_BRANCH
+        $mergebase = git merge-base HEAD FETCH_HEAD
         $changes = git diff --name-only HEAD $mergebase | grep -vE '(\.rst$)|(^Doc)|(^Misc)'
         If (!$changes) {
           echo 'Only docs were updated, stopping build process.'
           Exit-AppveyorBuild
         }
+        echo 'Doing full build due to non-doc changes in these files:'
+        echo $changes
       }