1 files changed, 9 insertions, 2 deletions

diff --git a/bin/get-package-updates b/bin/get-package-updates
index 1248fec..708b5ff 100755
--- a/bin/get-package-updates
+++ b/bin/get-package-updates
@@ -242,9 +242,16 @@ for repo in ${repo_names}; do
         git -C "${repo_path}" rev-parse HEAD
       )'"
     else
-      eval "new_repo_revisions__${repo}='$(
+      new_rev=$(
         git -C "${repo_path}" rev-list -n1 --until "${date_time}" HEAD
-      )'"
+      )
+      eval 'old_rev="${old_repo_revisions__'"${repo}"'}"'
+      # do not go backwards in time
+      # shellcheck disable=SC2154
+      if ! git -C "${repo_path}" merge-base --is-ancestor "${old_rev}" "${new_rev}"; then
+        new_rev="${old_rev}"
+      fi
+      eval "new_repo_revisions__${repo}='${new_rev}'"
     fi
   else
     eval 'new_repo_revisions__'"${repo}"'="${old_repo_revisions__'"${repo}"'}"'