diff --git a/git-flow b/git-flow
index 7f8c90c..84adc05 100755
--- a/git-flow
+++ b/git-flow
@@ -19,11 +19,6 @@
 fi
 
 export GITFLOW_DIR=$(dirname "$0")
-export GIT_DIR=$(git rev-parse --git-dir)
-export MASTER_BRANCH=$(git config --get gitflow.branch.master || echo master)
-export DEVELOP_BRANCH=$(git config --get gitflow.branch.develop || echo develop)
-export ORIGIN=$(git config --get gitflow.origin || echo origin)
-export README=$(git config --get gitflow.readme || echo README)
 
 usage() {
 	echo "usage: git flow <subcommand>"
@@ -62,10 +57,6 @@
 		exit 1
 	fi
 
-	if ! git rev-parse --git-dir >/dev/null; then
-		die "Not a git repository"
-	fi
-
 	# run command
 	. "$GITFLOW_DIR/git-flow-$SUBCOMMAND"
 	FLAGS_PARENT="git flow $SUBCOMMAND"
diff --git a/git-flow-feature b/git-flow-feature
index d65da94..d005648 100644
--- a/git-flow-feature
+++ b/git-flow-feature
@@ -12,7 +12,10 @@
 # Copyright (c) 2010 by Benedikt Böhm
 #
 
-PREFIX=$(git config --get gitflow.prefix.feature || echo feature/)
+gitflow_require_git_repo
+gitflow_require_initialized
+gitflow_load_settings
+PREFIX=$(git config --get gitflow.prefix.feature)
 
 usage() {
 	echo "usage: git flow feature [list] [-v]"
@@ -35,7 +38,7 @@
 	local feature_branches
 	local current_branch
 	local short_names
-	feature_branches=$(echo "$LOCAL_BRANCHES" | grep "^$PREFIX")
+	feature_branches=$(echo "$(gitflow_local_branches)" | grep "^$PREFIX")
 	if [ -z "$feature_branches" ]; then
 		warn "No feature branches exist."
 		exit 0
@@ -184,7 +187,7 @@
 	gitflow_require_branch "$BRANCH"
 
 	# detect if we're restoring from a merge conflict
-	if [ -f "$GIT_DIR/.gitflow/MERGE_BASE" ]; then
+	if [ -f "$DOT_GIT_DIR/.gitflow/MERGE_BASE" ]; then
 		#
 		# TODO: detect that we're working on the correct branch here!
 		# The user need not necessarily have given the same $NAME twice here
@@ -195,20 +198,20 @@
 		# exit code for "unmerged changes in working tree", which we should
 		# actually be testing for here
 		if gitflow_test_clean_working_tree; then
-			FINISH_BASE=$(cat "$GIT_DIR/.gitflow/MERGE_BASE")
+			FINISH_BASE=$(cat "$DOT_GIT_DIR/.gitflow/MERGE_BASE")
 
 			# Since the working tree is now clean, either the user did a
 			# succesfull merge manually, or the merge was cancelled.
 			# We detect this using gitflow_is_branch_merged_into()
 			if gitflow_is_branch_merged_into "$BRANCH" "$FINISH_BASE"; then
-				rm -f "$GIT_DIR/.gitflow/MERGE_BASE"
+				rm -f "$DOT_GIT_DIR/.gitflow/MERGE_BASE"
 				helper_finish_cleanup
 				exit 0
 			else
 				# If the user cancelled the merge and decided to wait until later,
 				# that's fine. But we have to acknowledge this by removing the
 				# MERGE_BASE file and continuing normal execution of the finish
-				rm -f "$GIT_DIR/.gitflow/MERGE_BASE"
+				rm -f "$DOT_GIT_DIR/.gitflow/MERGE_BASE"
 			fi
 		else
 			echo
@@ -231,7 +234,7 @@
 		git fetch -q "$ORIGIN" "$BRANCH"
 	fi
 
-	if has "$ORIGIN/$BRANCH" "$REMOTE_BRANCHES"; then
+	if has "$ORIGIN/$BRANCH" "$(gitflow_remote_branches)"; then
 		gitflow_require_branches_equal "$BRANCH" "$ORIGIN/$BRANCH"
 	fi
 	gitflow_require_branches_equal "$DEVELOP_BRANCH" "$ORIGIN/$DEVELOP_BRANCH"
@@ -258,8 +261,8 @@
 	if [ $? -ne 0 ]; then
 		# oops.. we have a merge conflict!
 		# write the given $DEVELOP_BRANCH to a temporary file (we need it later)
-		mkdir -p "$GIT_DIR/.gitflow"
-		echo "$DEVELOP_BRANCH" > "$GIT_DIR/.gitflow/MERGE_BASE"
+		mkdir -p "$DOT_GIT_DIR/.gitflow"
+		echo "$DEVELOP_BRANCH" > "$DOT_GIT_DIR/.gitflow/MERGE_BASE"
 		echo
 		echo "There were merge conflicts. To resolve the merge conflict manually, use:"
 		echo "    git mergetool"
diff --git a/git-flow-hotfix b/git-flow-hotfix
index 9def3af..347b811 100644
--- a/git-flow-hotfix
+++ b/git-flow-hotfix
@@ -12,8 +12,11 @@
 # Copyright (c) 2010 by Benedikt Böhm
 #
 
+gitflow_require_git_repo
+gitflow_require_initialized
+gitflow_load_settings
 VERSION_PREFIX=$(git config --get gitflow.prefix.versiontag)
-PREFIX=$(git config --get gitflow.prefix.hotfix || echo hotfix/)
+PREFIX=$(git config --get gitflow.prefix.hotfix)
 
 usage() {
 	echo "usage: git flow hotfix [list] [-v]"
@@ -32,7 +35,7 @@
 	local hotfix_branches
 	local current_branch
 	local short_names
-	hotfix_branches=$(echo "$LOCAL_BRANCHES" | grep "^$PREFIX")
+	hotfix_branches=$(echo "$(gitflow_local_branches)" | grep "^$PREFIX")
 	if [ -z "$hotfix_branches" ]; then
 		warn "No hotfix branches exist."
 		exit 0
@@ -113,7 +116,7 @@
 }
 
 require_no_existing_hotfix_branches() {
-	local hotfix_branches=$(echo "$LOCAL_BRANCHES" | grep "^$PREFIX")
+	local hotfix_branches=$(echo "$(gitflow_local_branches)" | grep "^$PREFIX")
 	local first_branch=$(echo ${hotfix_branches} | head -n1)
 	first_branch=${first_branch#$PREFIX}
 	[ -z "$hotfix_branches" ] || \
diff --git a/git-flow-init b/git-flow-init
index 4c43b31..364420a 100644
--- a/git-flow-init
+++ b/git-flow-init
@@ -16,59 +16,219 @@
 	echo "usage: git flow init"
 }
 
+parse_args() {
+	# parse options
+	FLAGS "$@" || exit $?
+	eval set -- "${FLAGS_ARGV}"
+}
+
 # Default entry when no SUBACTION is given
 cmd_default() {
-	echo
-	echo "Summary of actions:"
+	DEFINE_boolean force false 'force setting of gitflow branches, even if already configured' f
+	parse_args "$@"
 
 	if ! git rev-parse --git-dir >/dev/null 2>&1; then
-		git init --quiet
-		echo "- A new git repository at $PWD was created"
-	fi
-
-	if ! git rev-parse --quiet --verify HEAD >/dev/null 2>&1; then
-		touch "$README"
-		git add "$README"
-		git commit --quiet -m "initial commit"
-		if [ "$MASTER_BRANCH" != "master" ]; then
-			git branch -m master "$MASTER_BRANCH"
-		fi
-		echo "- An initial commit was created at branch '$MASTER_BRANCH'"
-	fi
-
-	if ! git rev-parse --verify "$MASTER_BRANCH" >/dev/null 2>&1; then
-		die "Cannot find your master branch. Try: git branch -m <mymaster> $MASTER_BRANCH"
-	fi
-
-	gitflow_require_clean_working_tree
-
-	if git remote | grep -q "$ORIGIN"; then
-		git fetch -q "$ORIGIN"
-		gitflow_require_branches_equal "$MASTER_BRANCH" "$ORIGIN/$MASTER_BRANCH"
-	fi
-
-	if git rev-parse --verify "$DEVELOP_BRANCH" >/dev/null 2>&1; then
-		gitflow_require_branches_equal "$DEVELOP_BRANCH" "$ORIGIN/$DEVELOP_BRANCH"
+		git init
 	else
-		git checkout -q -b "$DEVELOP_BRANCH" "$MASTER_BRANCH"
-		echo "- A new branch '$DEVELOP_BRANCH' was created"
-		echo "- You are now on branch '$DEVELOP_BRANCH'"
+		# assure that we are not working in a repo with local changes
+		git_repo_is_headless || gitflow_require_clean_working_tree
 	fi
 
-	if ! git remote | grep -q "$ORIGIN"; then
-		if [ "$1" = "" ]; then
-			echo "- No remote location was added. Try: git remote add $ORIGIN <url>"
+	# running git flow init on an already initialized repo is fine
+	if gitflow_is_initialized && ! flag force; then
+		warn "Already initialized for gitflow."
+		warn "To force reinitialization, use: git flow init -f"
+		exit 0
+	fi
+
+	local branch_count
+	local answer
+
+	# add a master branch if no such branch exists yet
+	local master_branch
+	if gitflow_has_master_configured && ! flag force; then
+		master_branch=$(git config --get gitflow.branch.master)
+	else
+		# Two cases are distinguished:
+		# 1. A fresh git repo (without any branches)
+		#    We will create a new master/develop branch for the user
+		# 2. Some branches do already exist
+		#    We will disallow creation of new master/develop branches and
+		#    rather allow to use existing branches for git-flow.
+		local default_suggestion
+		local should_check_existence
+		branch_count=$(gitflow_local_branches | wc -l)
+		if [ "$branch_count" -eq 0 ]; then
+			echo "No branches exist yet. Base branches must be created now."
+			should_check_existence=NO
+			default_suggestion=master
 		else
-			git remote add "$ORIGIN" "$1"
-			echo "- A new remote location '$1' was added"
+			echo
+			echo "Which branch should be used for bringing forth production releases?"
+			gitflow_local_branches | sed 's/^.*$/   - &/g'
+
+			should_check_existence=YES
+			default_suggestion=
+			for guess in 'production' 'main' 'master'; do
+				if gitflow_local_branch_exists "$guess"; then
+					default_suggestion="$guess"
+					break
+				fi
+			done
 		fi
+
+		echo "Branch name for production releases: [$default_suggestion] \c"
+		read answer
+		master_branch=${answer:-$default_suggestion}
+
+		# check existence in case of an already existing repo
+		if [ "$should_check_existence" = "YES" ]; then
+			gitflow_local_branch_exists "$master_branch" || \
+				die "Local branch '$master_branch' does not exist."
+		fi
+
+		# store the name of the master branch
+		git config gitflow.branch.master "$master_branch"
 	fi
 
+	# add a develop branch if no such branch exists yet
+	local develop_branch
+	if gitflow_has_develop_configured && ! flag force; then
+		develop_branch=$(git config --get gitflow.branch.develop)
+	else
+		# Again, the same two cases as with the master selection are
+		# considered (fresh repo or repo that contains branches)
+		local default_suggestion
+		local should_check_existence
+		branch_count=$(gitflow_local_branches | grep -v "^${master_branch}\$" | wc -l)
+		if [ "$branch_count" -eq 0 ]; then
+			should_check_existence=NO
+			default_suggestion=develop
+		else
+			echo
+			echo "Which branch should be used for integration of the \"next release\"?"
+			gitflow_local_branches | grep -v "^${master_branch}\$" | sed 's/^.*$/   - &/g'
+
+			should_check_existence=YES
+			default_suggestion=
+			for guess in 'develop' 'int' 'integration' 'master'; do
+				if gitflow_local_branch_exists "$guess"; then
+					default_suggestion="$guess"
+					break
+				fi
+			done
+		fi
+
+		echo "Branch name for \"next release\" development: [$default_suggestion] \c"
+		read answer
+		develop_branch=${answer:-$default_suggestion}
+
+		if [ "$master_branch" = "$develop_branch" ]; then
+			die "Production and integration branches should differ."
+		fi
+
+		# check existence in case of an already existing repo
+		if [ "$should_check_existence" = "YES" ]; then
+			gitflow_local_branch_exists "$develop_branch" || \
+				die "Local branch '$develop_branch' does not exist."
+		fi
+
+		# store the name of the develop branch
+		git config gitflow.branch.develop "$develop_branch"
+	fi
+
+	# Creation of HEAD
+	# ----------------
+	# We create a HEAD now, if it does not exist yet (in a fresh repo). We need
+	# it to be able to create new branches.
+	local created_gitflow_branch=0
+	if ! git rev-parse --quiet --verify HEAD >/dev/null 2>&1; then
+		git symbolic-ref HEAD "refs/heads/$master_branch"
+		git commit --allow-empty --quiet -m "Initial commit"
+		created_gitflow_branch=1
+	fi
+
+	# Creation of master
+	# ------------------
+	# At this point, there always is a master branch: either it existed already
+	# (and was picked interactively as the production branch) or it has just
+	# been created in a fresh repo
+
+	# Creation of develop
+	# -------------------
+	# The develop branch possibly does not exist yet.  This is the case when,
+	# in a git init'ed repo with one or more commits, master was picked as the
+	# default production branch and develop was "created".  We should create
+	# the develop branch now in that case (we base it on master, of course)
+	if ! gitflow_local_branch_exists "$develop_branch"; then
+		git branch "$develop_branch" "$master_branch"
+		created_gitflow_branch=1
+	fi
+
+	# assert the gitflow repo has been correctly initialized
+	gitflow_is_initialized
+
+	# switch to develop branch if its newly created
+	if [ $created_gitflow_branch -eq 1 ]; then
+		git checkout -q "$develop_branch"
+	fi
+
+	# finally, ask the user for naming conventions (branch and tag prefixes)
 	echo
+	echo "How to name your supporting branch prefixes?"
 
-	if git remote | grep -q "$ORIGIN"; then
-		git push "$ORIGIN" "$MASTER_BRANCH" "$DEVELOP_BRANCH"
+	local prefix
+
+	# Feature branches
+	if ! git config --get gitflow.prefix.feature >/dev/null 2>&1 || flag force; then
+		default_suggestion=$(git config --get gitflow.prefix.feature || echo feature/)
+		echo "Feature branches? [$default_suggestion] \c"
+		read answer
+		[ "$answer" = "-" ] && prefix= || prefix=${answer:-$default_suggestion}
+		git config gitflow.prefix.feature "$prefix"
 	fi
+
+	# Release branches
+	if ! git config --get gitflow.prefix.release >/dev/null 2>&1 || flag force; then
+		default_suggestion=$(git config --get gitflow.prefix.release || echo release/)
+		echo "Release branches? [$default_suggestion] \c"
+		read answer
+		[ "$answer" = "-" ] && prefix= || prefix=${answer:-$default_suggestion}
+		git config gitflow.prefix.release "$prefix"
+	fi
+
+
+	# Hotfix branches
+	if ! git config --get gitflow.prefix.hotfix >/dev/null 2>&1 || flag force; then
+		default_suggestion=$(git config --get gitflow.prefix.hotfix || echo hotfix/)
+		echo "Hotfix branches? [$default_suggestion] \c"
+		read answer
+		[ "$answer" = "-" ] && prefix= || prefix=${answer:-$default_suggestion}
+		git config gitflow.prefix.hotfix "$prefix"
+	fi
+
+
+	# Support branches
+	if ! git config --get gitflow.prefix.support >/dev/null 2>&1 || flag force; then
+		default_suggestion=$(git config --get gitflow.prefix.support || echo support/)
+		echo "Support branches? [$default_suggestion] \c"
+		read answer
+		[ "$answer" = "-" ] && prefix= || prefix=${answer:-$default_suggestion}
+		git config gitflow.prefix.support "$prefix"
+	fi
+
+
+	# Version tag prefix
+	if ! git config --get gitflow.prefix.versiontag >/dev/null 2>&1 || flag force; then
+		default_suggestion=$(git config --get gitflow.prefix.versiontag || echo "")
+		echo "Version tag prefix? [$default_suggestion] \c"
+		read answer
+		[ "$answer" = "-" ] && prefix= || prefix=${answer:-$default_suggestion}
+		git config gitflow.prefix.versiontag "$prefix"
+	fi
+
+
+	# TODO: what to do with origin?
 }
 
 cmd_help() {
diff --git a/git-flow-release b/git-flow-release
index 602412e..9aedf3c 100644
--- a/git-flow-release
+++ b/git-flow-release
@@ -12,8 +12,11 @@
 # Copyright (c) 2010 by Benedikt Böhm
 #
 
+gitflow_require_git_repo
+gitflow_require_initialized
+gitflow_load_settings
 VERSION_PREFIX=$(git config --get gitflow.prefix.versiontag)
-PREFIX=$(git config --get gitflow.prefix.release || echo release/)
+PREFIX=$(git config --get gitflow.prefix.release)
 
 usage() {
 	echo "usage: git flow release [list] [-v]"
@@ -43,7 +46,7 @@
 	local release_branches
 	local current_branch
 	local short_names
-	release_branches=$(echo "$LOCAL_BRANCHES" | grep "^$PREFIX")
+	release_branches=$(echo "$(gitflow_local_branches)" | grep "^$PREFIX")
 	if [ -z "$release_branches" ]; then
 		warn "No release branches exist."
 		exit 0
@@ -119,7 +122,7 @@
 }
 
 require_no_existing_release_branches() {
-	local release_branches=$(echo "$LOCAL_BRANCHES" | grep "^$PREFIX")
+	local release_branches=$(echo "$(gitflow_local_branches)" | grep "^$PREFIX")
 	local first_branch=$(echo ${release_branches} | head -n1)
 	first_branch=${first_branch#$PREFIX}
 	[ -z "$release_branches" ] || \
diff --git a/git-flow-support b/git-flow-support
index 804a01d..8a8ac56 100644
--- a/git-flow-support
+++ b/git-flow-support
@@ -12,8 +12,11 @@
 # Copyright (c) 2010 by Benedikt Böhm
 #
 
+gitflow_require_git_repo
+gitflow_require_initialized
+gitflow_load_settings
 VERSION_PREFIX=$(git config --get gitflow.prefix.versiontag)
-PREFIX=$(git config --get gitflow.prefix.support || echo support/)
+PREFIX=$(git config --get gitflow.prefix.support)
 
 warn "note: The support subcommand is still very EXPERIMENTAL!"
 warn "note: DO NOT use it in a production situation."
@@ -34,7 +37,7 @@
 	local support_branches
 	local current_branch
 	local short_names
-	support_branches=$(echo "$LOCAL_BRANCHES" | grep "^$PREFIX")
+	support_branches=$(echo "$(gitflow_local_branches)" | grep "^$PREFIX")
 	if [ -z "$support_branches" ]; then
 		warn "No support branches exist."
 		exit 0
diff --git a/gitflow-common b/gitflow-common
index 8efc365..9702818 100644
--- a/gitflow-common
+++ b/gitflow-common
@@ -38,11 +38,46 @@
 # Git specific common functionality
 #
 
+# check if this repo has been inited for gitflow
+gitflow_has_master_configured() {
+	local master=$(git config --get gitflow.branch.master)
+	[ "$master" != "" ] && gitflow_local_branch_exists "$master"
+}
+
+gitflow_has_develop_configured() {
+	local develop=$(git config --get gitflow.branch.develop)
+	[ "$develop" != "" ] && gitflow_local_branch_exists "$develop"
+}
+
+gitflow_has_prefixes_configured() {
+	git config --get gitflow.prefix.feature >/dev/null 2>&1     && \
+	git config --get gitflow.prefix.release >/dev/null 2>&1     && \
+	git config --get gitflow.prefix.hotfix >/dev/null 2>&1      && \
+	git config --get gitflow.prefix.support >/dev/null 2>&1     && \
+	git config --get gitflow.prefix.versiontag >/dev/null 2>&1
+}
+
+gitflow_is_initialized() {
+	gitflow_has_master_configured                    && \
+	gitflow_has_develop_configured                   && \
+	[ "$(git config --get gitflow.branch.master)" !=    \
+	  "$(git config --get gitflow.branch.develop)" ] && \
+	gitflow_has_prefixes_configured
+}
+
 # get all available branches
-LOCAL_BRANCHES=$(git branch | sed 's/^[* ] //')
-REMOTE_BRANCHES=$(git branch -r | sed 's/^[* ] //')
-ALL_BRANCHES="$LOCAL_BRANCHES $REMOTE_BRANCHES"
-ALL_TAGS=$(git tag)
+gitflow_local_branches() { git branch | sed 's/^[* ] //'; }
+gitflow_remote_branches() { git branch -r | sed 's/^[* ] //'; }
+gitflow_all_branches() { ( git branch; git branch -r) | sed 's/^[* ] //'; }
+gitflow_all_tags() { git tag; }
+
+# loading settings that can be overridden using git config
+gitflow_load_settings() {
+	export DOT_GIT_DIR=$(git rev-parse --git-dir >/dev/null 2>&1)
+	export MASTER_BRANCH=$(git config --get gitflow.branch.master)
+	export DEVELOP_BRANCH=$(git config --get gitflow.branch.develop)
+	export ORIGIN=$(git config --get gitflow.origin || echo origin)
+}
 
 #
 # resolve_nameprefix
@@ -51,8 +86,8 @@
 # $1 = name prefix to resolve
 # $2 = branch prefix to use
 #
-# Searches branch names from LOCAL_BRANCHES to look for a unique branch
-# name whose name starts with the given name prefix.
+# Searches branch names from gitflow_local_branches() to look for a unique
+# branch name whose name starts with the given name prefix.
 #
 # There are multiple exit codes possible:
 # 0: The unambiguous full name of the branch is written to stdout
@@ -67,12 +102,12 @@
 	local num_matches
 
 	# first, check if there is a perfect match
-	if has "$LOCAL_BRANCHES" "$prefix$name"; then
+	if has "$(gitflow_local_branches)" "$prefix$name"; then
 		echo "$name"
 		return 0
 	fi
 
-	matches=$(echo "$LOCAL_BRANCHES" | grep "^$prefix$name")
+	matches=$(echo "$(gitflow_local_branches)" | grep "^$prefix$name")
 	num_matches=$(echo "$matches" | wc -l)
 	if [ -z "$matches" ]; then
 		# no prefix match, so take it literally
@@ -107,6 +142,22 @@
 	fi
 }
 
+gitflow_require_git_repo() {
+	if ! git rev-parse --git-dir >/dev/null 2>&1; then
+		die "fatal: Not a git repository"
+	fi
+}
+
+gitflow_require_initialized() {
+	if ! gitflow_is_initialized; then
+		die "fatal: Not a gitflow-enabled repo yet. Please run \"git flow init\" first."
+	fi
+}
+
+git_repo_is_headless() {
+	! git rev-parse --quiet --verify HEAD >/dev/null 2>&1
+}
+
 gitflow_require_clean_working_tree() {
 	gitflow_test_clean_working_tree
 	local result=$?
@@ -118,40 +169,48 @@
 	fi
 }
 
+gitflow_local_branch_exists() {
+	has $1 $(gitflow_local_branches)
+}
+
+gitflow_branch_exists() {
+	has $1 $(gitflow_all_branches)
+}
+
+gitflow_tag_exists() {
+	has $1 $(gitflow_all_tags)
+}
+
 gitflow_require_local_branch() {
-	if ! has $1 $LOCAL_BRANCHES; then
+	if ! gitflow_local_branch_exists; then
 		die "fatal: Local branch '$1' does not exist and is required."
 	fi
 }
 
 gitflow_require_remote_branch() {
-	if ! has $1 $REMOTE_BRANCHES; then
+	if ! has $1 $(gitflow_remote_branches); then
 		die "Remote branch '$1' does not exist and is required."
 	fi
 }
 
 gitflow_require_branch() {
-	if ! has $1 $ALL_BRANCHES; then
+	if ! has $1 $(gitflow_all_branches); then
 		die "Branch '$1' does not exist and is required."
 	fi
 }
 
 gitflow_require_branch_absent() {
-	if has $1 $ALL_BRANCHES; then
+	if has $1 $(gitflow_all_branches); then
 		die "Branch '$1' already exists. Pick another name."
 	fi
 }
 
 gitflow_require_tag_absent() {
-	if has $1 $ALL_TAGS; then
+	if has $1 $(gitflow_all_tags); then
 		die "Tag '$1' already exists. Pick another name."
 	fi
 }
 
-gitflow_tag_exists() {
-	has $1 $ALL_TAGS
-}
-
 #
 # gitflow_test_branches_equal()
 #
@@ -162,13 +221,16 @@
 # 1    First given branch needs fast-forwarding
 # 2    Second given branch needs fast-forwarding
 # 3    Branch needs a real merge
+# 4    There is no merge base, i.e. the branches have no common ancestors
 #
 gitflow_test_branches_equal() {
 	local commit1=$(git rev-parse "$1")
 	local commit2=$(git rev-parse "$2")
 	if [ "$commit1" != "$commit2" ]; then
 		local base=$(git merge-base "$commit1" "$commit2")
-		if [ "$commit1" = "$base" ]; then
+		if [ $? -ne 0 ]; then
+			return 4
+		elif [ "$commit1" = "$base" ]; then
 			return 1
 		elif [ "$commit2" = "$base" ]; then
 			return 2