From 6669c27376766fc79ac4ad27c3ad2b59320e5740 Mon Sep 17 00:00:00 2001
From: Eric Van Norman <ericvn@us.ibm.com>
Date: Wed, 16 Jun 2021 16:37:32 -0500
Subject: [PATCH] Update to use first commit's parent sha to find file
 differences

---
 tools/check_release_notes.sh | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/tools/check_release_notes.sh b/tools/check_release_notes.sh
index c651d31b9fb..a0e9bd438b6 100755
--- a/tools/check_release_notes.sh
+++ b/tools/check_release_notes.sh
@@ -72,7 +72,7 @@ get_opts() {
             shift 2
             ;;
         --base-sha)
-            PULL_BASE_SHA="$2"
+            base_sha="$2"
             shift 2
             ;;
         --pr-head-sha)
@@ -122,11 +122,6 @@ validate_opts() {
         exit 1
     fi
 
-    if [ -z "${PULL_BASE_SHA:-}" ]; then
-        echo "PULL_BASE_SHA not specified. This must match the base SHA for the pull request."
-        exit 1
-    fi
-
     if [ -z "${REPO_PATH:-}" ]; then
         echo "REPO_PATH not specified. Using current working directory."
         REPO_PATH=$(pwd)
@@ -134,12 +129,17 @@ validate_opts() {
         echo "Using REPO_PATH ${REPO_PATH}"
     fi
 
+        if [ -z "${base_sha:-}" ]; then
+        echo "base-sha not specified. Calculating from the PULL_NUMBER"
+        base_sha=$(curl -s -H "Accept: application/vnd.github.v3+json" https://api.github.com/repos/"${REPO_OWNER}"/"${REPO_NAME}"/pulls/"${PULL_NUMBER}"/commits | jq -r '.[0].parents[0].sha')
+        echo "base_sha: ""${base_sha}"""
+    fi
 }
 
 # Curl the GitHub API to get a list of files for the specified PR. If files are
 # found, exit. We might eventually want to validate the data here.
 checkForFiles() {
-    echo "Checking files from pull request ${REPO_OWNER}/${REPO_NAME}#${PULL_NUMBER} head SHA: ${PULL_PULL_SHA} destination branch: ${PULL_BASE_REF}, base SHA: ${PULL_BASE_SHA}"
+    echo "Checking files from pull request ${REPO_OWNER}/${REPO_NAME}#${PULL_NUMBER} head SHA: ${PULL_PULL_SHA} destination branch: ${PULL_BASE_REF}, base SHA: ${base_sha}"
 
     pushd "${REPO_PATH}"
 
@@ -149,7 +149,7 @@ checkForFiles() {
     popd
 
     set +e
-    "${GEN_RELEASE_NOTES_PATH}"/gen-release-notes --oldBranch "${PULL_BASE_SHA}" --newBranch "${PULL_PULL_SHA}" --templates "${GEN_RELEASE_NOTES_PATH}"/templates --notes ./releasenotes/notes --validateOnly
+    "${GEN_RELEASE_NOTES_PATH}"/gen-release-notes --oldBranch "${base_sha}" --newBranch "${PULL_PULL_SHA}" --templates "${GEN_RELEASE_NOTES_PATH}"/templates --notes ./releasenotes/notes --validateOnly
     returnCode=$?
     set -e
 
@@ -183,7 +183,7 @@ function validateNotes() {
     popd
 
     local errorOccurred=0
-    git diff-tree -r --diff-filter=AMR --name-only --relative=releasenotes/notes "${PULL_BASE_SHA}" "${PULL_PULL_SHA}" | \
+    git diff-tree -r --diff-filter=AMR --name-only --relative=releasenotes/notes "${base_sha}" "${PULL_PULL_SHA}" | \
     {
     set +e
     while read -r line; do