fix: Error when image file is on first commit... why?

scripts/run

@@ -88,20 +88,25 @@ optimizer() {
 }
 
 optimizer_git_image() {
+  first_commit_hash=$(git rev-list --max-parents=0 HEAD)
+
+  # https://stackoverflow.com/a/48999882/6429616
+  # install git alias amend-to with auto stash
+  check_git_command=`git config --global --list | grep amend-to | wc -c`
+  if [ "$check_git_command" -ne 187 ]; then
+    git config --global alias.amend-to '!f() { SHA=`git rev-parse "$1"`; git stash -k && git commit --fixup "$SHA" && GIT_SEQUENCE_EDITOR=true git rebase --interactive --autosquash "$SHA^" && git stash pop; }; f'
+  fi
+
   for file in $(git diff --name-only --diff-filter=M --ignore-submodules); do
-    last_commit=`git log -n 1 --pretty=format:%H -- $file`
+    last_file_update_commit_hash=`git log -n 1 --pretty=format:%H -- $file`
     current_size=`cat $file | wc -c`
-    old_size=`git cat-file -p $last_commit:$file | wc -c`
+    old_size=`git cat-file -p $last_file_update_commit_hash:$file | wc -c`
 
-    # https://stackoverflow.com/a/48999882/6429616
+    if [ "$first_commit_hash" == "$last_file_update_commit_hash" ]; then
-    check_git_command=`git config --global --list | grep amend-to | wc -c`
+      echo "💩 file '$file' is on first commit..."
-    if [ "$check_git_command" -ne 187 ]; then
+    elif [ "$current_size" -lt "$old_size" ]; then
-      git config --global alias.amend-to '!f() { SHA=`git rev-parse "$1"`; git stash -k && git commit --fixup "$SHA" && GIT_SEQUENCE_EDITOR=true git rebase --interactive --autosquash "$SHA^" && git stash pop; }; f'
-    fi
-
-    if [ "$current_size" -lt "$old_size" ]; then
       git add $file
-      git amend-to $last_commit
+      git amend-to $last_file_update_commit_hash
     fi
   done
 }