Merge pull request #641 from tj/fix_pull_request_upstream

pull_request: should use detected upstream instead of hardcore origin

Author: hemanth

bin/git-pull-request

@@ -41,16 +41,22 @@ test -z "$user" && abort "git config user.email required"
 # branch
 
 branch=${1-$(git symbolic-ref HEAD | sed 's/refs\/heads\///')}
+remote=$(git config branch."$branch".remote)
+if [ -z "$remote" ]; then
+    echo 'no upstream found, push to origin as default'
+    remote="origin"
+fi
+[ "$remote" == "." ] && abort "the upstream should be a remote branch."
 
 # make sure it's pushed
 
-git push origin "$branch" || abort "failed to push $branch"
+git push "$remote" "$branch" || abort "failed to push $branch"
 
-origin=$(git config remote.origin.url)
-if [[ $origin == git@* ]]; then
-    project=${origin##*:}
+remote_url=$(git config remote."$remote".url)
+if [[ "$remote_url" == git@* ]]; then
+    project=${remote_url##*:}
 else
-    project=${origin#https://*/}
+    project=${remote_url#https://*/}
 fi
 project=${project%.git}