chore: update the default sha (#896)

action.yml

@@ -46,7 +46,6 @@ inputs:
   sha:
     description: "Specify a different commit SHA used for comparing changes"
     required: false
-    default: ${{ github.sha }}
   base_sha:
     description: "Specify a different base commit SHA used for comparing changes"
     required: false
@@ -174,6 +173,7 @@ runs:
         GITHUB_SERVER_URL: ${{ github.server_url }}
         GITHUB_REPOSITORY: ${{ github.repository }}
         GITHUB_REF: ${{ github.ref }}
+        GITHUB_SHA: ${{ github.sha }}
         GITHUB_BASE_REF: ${{ github.base_ref }}
         GITHUB_HEAD_REF: ${{ github.head_ref }}
         GITHUB_WORKSPACE: ${{ github.workspace }}

diff-sha.sh

@@ -54,6 +54,11 @@ if [[ -z $GITHUB_BASE_REF ]]; then
   echo "Running on a push event..."
   TARGET_BRANCH=$GITHUB_REFNAME
   CURRENT_BRANCH=$TARGET_BRANCH
+
+  echo "Fetching remote refs..."
+
+  # shellcheck disable=SC2086
+  git fetch $EXTRA_ARGS -u --progress --deepen="$INPUT_FETCH_DEPTH" origin "$CURRENT_BRANCH" 1>/dev/null 2>&1
 
   echo "::debug::Getting HEAD SHA..."
   if [[ -n "$INPUT_UNTIL" ]]; then
@@ -68,8 +73,6 @@ if [[ -z $GITHUB_BASE_REF ]]; then
     if [[ -z $INPUT_SHA ]]; then
       CURRENT_SHA=$(git rev-list -n 1 HEAD) && exit_status=$? || exit_status=$?
     else
-      # shellcheck disable=SC2086
-      git fetch $EXTRA_ARGS -u --progress --deepen="$INPUT_FETCH_DEPTH" origin "$CURRENT_BRANCH" 1>/dev/null 2>&1
       CURRENT_SHA=$INPUT_SHA; exit_status=$?
     fi
   fi
@@ -131,8 +134,6 @@ if [[ -z $GITHUB_BASE_REF ]]; then
       fi
     fi
   else
-    # shellcheck disable=SC2086
-    git fetch $EXTRA_ARGS -u --progress --deepen="$INPUT_FETCH_DEPTH" origin "$CURRENT_BRANCH" 1>/dev/null 2>&1
     PREVIOUS_SHA=$INPUT_BASE_SHA
   fi
 
@@ -174,10 +175,6 @@ else
       CURRENT_SHA=$(git rev-list -n 1 HEAD) && exit_status=$? || exit_status=$?
     else
       CURRENT_SHA=$INPUT_SHA; exit_status=$?
-
-      if [[ "$CURRENT_SHA" == "$GITHUB_EVENT_PULL_REQUEST_HEAD_SHA" ]]; then
-        CURRENT_SHA=$(git rev-list -n 1 HEAD) && exit_status=$? || exit_status=$?
-      fi
     fi
   fi