git pull error fatal refusing to merge unrelated histories code example

Example 1: git unrelated histories

git merge upstream/master --allow-unrelated-histories

Example 2: fatal: refusing to merge unrelated histories

git pull origin master --allow-unrelated-histories
then when asked for merging vim editor opens click insert (i) type msg and :wq to save and exit

Example 3: refusing to merge unrelated histories git

I think its get sorted after using below command
>git pull --allow-unrelated-histories