[PATCH 1/2] sh-setup: Write a new require_clean_work_tree function

[Ramkumar Ramachandra <artagnon@gmail.com>]

Write a new require_clean_work_tree function to error out when working
tree contains unstaged changes or index contains uncommitted changes.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
---
 git-sh-setup.sh |   23 +++++++++++++++++++++++
 1 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/git-sh-setup.sh b/git-sh-setup.sh
index 6131670..3a337da 100644
--- a/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@ -145,6 +145,29 @@ require_work_tree () {
 	die "fatal: $0 cannot be used without a working tree."
 }
 
+require_clean_work_tree () {
+	# Update the index
+	git update-index -q --ignore-submodules --refresh
+
+	# Disallow unstaged changes in the working tree
+	if ! git diff-files --quiet --ignore-submodules --
+	then
+		echo >&2 "cannot $1: you have unstaged changes."
+		echo >&2 "Please commit or stash them."
+		git diff-files --name-status -r --ignore-submodules -- >&2
+		exit 1
+	fi
+
+	# Disallow uncommitted changes in the index
+	if ! git diff-index --cached --quiet --ignore-submodules HEAD --
+	then
+		echo >&2 "cannot $1: your index contains uncommitted changes."
+		echo >&2 "Please commit or stash them."
+		git diff-index --cached --name-status -r --ignore-submodules HEAD -- >&2
+		exit 1
+	fi
+}
+
 get_author_ident_from_commit () {
 	pick_author_script='
 	/^author /{
-- 
1.7.2.2.409.gdbb11.dirty