From 82495bfc550a0a40935805fd2b4a7eff2fd1a625 Mon Sep 17 00:00:00 2001
From: Will McVicker <willmcvicker@google.com>
Date: Tue, 4 May 2021 11:24:46 -0700
Subject: [PATCH] build_slider.sh: Detect if git knows about
 aosp/android12-5.10

If the user hasn't fetched aosp/android12-5.10, then checking the
merge-base against that branch will fail since it doesn't know about it.
So make sure to check if we got a sha1 before comparing to the repo
aosp/ revision.

Fixes: ceb955851850 ("build_slider: Throw a warning when trying to build AOSP ToT")
Signed-off-by: Will McVicker <willmcvicker@google.com>
Change-Id: I549d3184be9048116331ef78aea3d15e88d53c03
---
 build_slider.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/build_slider.sh b/build_slider.sh
index b6131dba4eab..cfd49d4598f5 100755
--- a/build_slider.sh
+++ b/build_slider.sh
@@ -99,7 +99,7 @@ if [ "${EXPERIMENTAL_BUILD}" = "0" -a "${BUILD_KERNEL}" != "0" ]; then
     # Booting AOSP ToT does not always work; throw a warning to prevent this.
     REPO_SHA=$(git log -1 --pretty="format:%H" m/s-dev-gs-pixel-5.10)
     LOCAL_MERGE_BASE=$(git merge-base HEAD aosp/android12-5.10)
-    if [ "${REPO_SHA}" != "${LOCAL_MERGE_BASE}" ]; then
+    if [ -n "${LOCAL_MERGE_BASE}" -a "${REPO_SHA}" != "${LOCAL_MERGE_BASE}" ]; then
       echo "Your aosp/ directory appears to be synced to a point beyond the"
       echo "  latest AOSP merge point. This is not supported, currently, as"
       echo "  it is prone to errors. Please base any changes on"