• Upload mybranch to origin
• Merge to master through PR
• Checkout mybranch and add commit
• git prune-merged -s prunes upstream branch for mybranch
• checkout mybranch and upload

Result:

$ git upload
Push to existing branch @{upstream}
fatal: remote part of refspec is not a valid name in mybranch:@{upstream}

Expected: New remote branch created and uploaded to

Version: 2d342f7 - (HEAD -> lovef.code/target-branches, origin/lovef.code/target-branches) target branches