[PATCH v2 2/2] Porcelain scripts: Rewrite cryptic "needs update" error message

[Ramkumar Ramachandra <artagnon@gmail.com>]

Although Git interally has the facility to differentiate between
porcelain and plubmbing commands and appropriately print errors,
several shell scripts invoke plubming commands triggering cryptic
plumbing errors to be displayed on a porcelain interface. This patch
replaces the "needs update" message in git-pull and git-rebase, when
`git update-index` is run, with a more friendly message.

Reported-by: Joshua Jensen <jjensen@workspacewhiz.com>
Cc: Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
---
 git-pull.sh                |    5 +----
 git-rebase--interactive.sh |   21 +++++----------------
 git-rebase.sh              |   14 +-------------
 3 files changed, 7 insertions(+), 33 deletions(-)

diff --git a/git-pull.sh b/git-pull.sh
index 8eb74d4..a15b545 100755
--- a/git-pull.sh
+++ b/git-pull.sh
@@ -201,10 +201,7 @@ test true = "$rebase" && {
 			die "updating an unborn branch with changes added to the index"
 		fi
 	else
-		git update-index --ignore-submodules --refresh &&
-		git diff-files --ignore-submodules --quiet &&
-		git diff-index --ignore-submodules --cached --quiet HEAD -- ||
-		die "refusing to pull with rebase: your working tree is not up-to-date"
+		require_clean_work_tree "pull with rebase"
 	fi
 	oldremoteref= &&
 	. git-parse-remote &&
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index a27952d..9546975 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -153,14 +153,6 @@ run_pre_rebase_hook () {
 	fi
 }
 
-require_clean_work_tree () {
-	# test if working tree is dirty
-	git rev-parse --verify HEAD > /dev/null &&
-	git update-index --ignore-submodules --refresh &&
-	git diff-files --quiet --ignore-submodules &&
-	git diff-index --cached --quiet HEAD --ignore-submodules -- ||
-	die "Working tree is dirty"
-}
 
 ORIG_REFLOG_ACTION="$GIT_REFLOG_ACTION"
 
@@ -557,12 +549,9 @@ do_next () {
 			exit "$status"
 		fi
 		# Run in subshell because require_clean_work_tree can die.
-		if ! (require_clean_work_tree)
+		if ! (require_clean_work_tree "rebase")
 		then
-			warn "Commit or stash your changes, and then run"
-			warn
-			warn "	git rebase --continue"
-			warn
+			warn "Then run git rebase --continue."
 			exit 1
 		fi
 		;;
@@ -740,7 +729,7 @@ do
 			die "Cannot read HEAD"
 		git update-index --ignore-submodules --refresh &&
 			git diff-files --quiet --ignore-submodules ||
-			die "Working tree is dirty"
+			die "Working tree is dirty. Please commit or stash your changes to proceed."
 
 		# do we have anything to commit?
 		if git diff-index --cached --quiet --ignore-submodules HEAD --
@@ -768,7 +757,7 @@ first and then run 'git rebase --continue' again."
 
 		record_in_rewritten "$(cat "$DOTEST"/stopped-sha)"
 
-		require_clean_work_tree
+		require_clean_work_tree "rebase"
 		do_rest
 		;;
 	--abort)
@@ -866,7 +855,7 @@ first and then run 'git rebase --continue' again."
 
 		comment_for_reflog start
 
-		require_clean_work_tree
+		require_clean_work_tree "rebase"
 
 		if test ! -z "$1"
 		then
diff --git a/git-rebase.sh b/git-rebase.sh
index 3335cee..c3ca8d5 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -416,19 +416,7 @@ else
 	fi
 fi
 
-# The tree must be really really clean.
-if ! git update-index --ignore-submodules --refresh > /dev/null; then
-	echo >&2 "cannot rebase: you have unstaged changes"
-	git diff-files --name-status -r --ignore-submodules -- >&2
-	exit 1
-fi
-diff=$(git diff-index --cached --name-status -r --ignore-submodules HEAD --)
-case "$diff" in
-?*)	echo >&2 "cannot rebase: your index contains uncommitted changes"
-	echo >&2 "$diff"
-	exit 1
-	;;
-esac
+require_clean_work_tree "rebase"
 
 if test -z "$rebase_root"
 then
-- 
1.7.2.2.409.gdbb11.dirty