git-refresh

#!/bin/bash

# Refresh tracking branch from its remote repo

RED_ON="\033[0;41m"
RED_OFF="\033[0m"
ERROR="${RED_ON}ERROR${RED_OFF}"

while (( "$#" )); do

    if [ "$1" == "-q" ]; then
	query_only="yes"
    elif [ "$1" == "-f" ]; then
	force_it="yes"
    elif [[ "$1" != -* ]] && [[ $l_branch == "" ]]; then
	l_branch="$1"
    else
	echo "Unexpected argument: $1"
	echo
	echo "Refresh tracking branch from its repo."
	echo "Syntax: git-refresh [-f] [branch]"
	echo "        git-refresh -q [branch]"
	echo
	echo "If no branch is given, current branch is used."
	echo "-f     Force. Otherwise only fast-forward."
	echo "-q     Query tracked remote branch."
	exit 1
    fi
    
    shift
done

curr_branch="$(git rev-parse --symbolic-full-name --abbrev-ref HEAD)"

if [[ "$l_branch" = "" ]]; then
    l_branch=$curr_branch
fi
if [ "$l_branch" = "HEAD" ]; then
    echo -e "$ERROR: Detached head"
    exit 1
fi


remote="$(git config branch.$l_branch.remote)"

if [ "$remote" == "" ]; then
    echo -e "$ERROR: Branch '$l_branch' is not tracking"
    exit 1
fi

full_r_branch="$(git config branch.$l_branch.merge)"

if [[ $full_r_branch =~ refs/heads/(.+) ]]; then
    r_branch=${BASH_REMATCH[1]}
    echo "'$l_branch' is tracking '$r_branch' at '$remote'"
else
    echo -e "$ERROR: Unknown remote branch format: '$full_r_branch'"
    exit 1
fi

if [ "$query_only" == "yes" ] ; then exit 1 ; fi

echo "git fetch $remote $r_branch"
if ! git fetch --no-tags $remote +$r_branch:refs/remotes/$remote/$r_branch ; then
    echo -e "$ERROR: Failed to fetch '$remote/$r_branch'"
    exit 1
fi

if [[ "$l_branch" == "$curr_branch" ]]; then
    if [ "$force_it" == "yes" ]; then
	git reset --hard refs/remotes/$remote/$r_branch || exit 1
	method="reset --hard"
    else
	git merge --ff-only refs/remotes/$remote/$r_branch || exit 1
	method="fast-forward"
    fi
else
    # Other branch
    if ! git-is-merged $l_branch refs/remotes/$remote/$r_branch > /dev/null ; then
	if [[ "$force_it" != "yes" ]]; then
	    echo -e "$ERROR: Cannot fast-forward '$l_branch' to '$remote/$r_branch'"
	    exit 1
	fi
	method="branch -f"
    else
	method="fast-forward"
    fi
    git branch -f $l_branch refs/remotes/$remote/$r_branch || exit 1
fi

echo
echo "Branch '$l_branch' was successfully refreshed from '$remote/$r_branch' (by $method)"
echo