libxfs-apply: Add option to only import patches into guilt stack

The script automatically detects the existence of a guilt stack, but
only conflict resolution mechanisms so far are either skip the patch or
fail the process.

It's easier to fix conflicts if all the patches are stacked in guilt, so
add an option to stack all the patches into guilt, without applying them,
for post-processing and conflict resolution in case automatic import fails.

stgit doesn't seem to have a way to import patches into its stack, so,
there is no similar patch aiming stgit.

The order of commits added to $commit_list also needs to be reversed
when only importing patches to the guilt stack.

Signed-off-by: Carlos Maiolino <cem@kernel.org>

tools/libxfs-apply

diff --git a/tools/libxfs-apply b/tools/libxfs-apply
index aa2530f..2b65684 100755
--- a/tools/libxfs-apply
+++ b/tools/libxfs-apply
@@ -9,7 +9,7 @@
 	echo $*
 	echo
 	echo "Usage:"
-	echo "	libxfs-apply [--verbose] --sob <name/email> --source <repodir> --commit <commit_id>"
+	echo "	libxfs-apply [--import-only] [--verbose] --sob <name/email> --source <repodir> --commit <commit_id>"
 	echo "	libxfs-apply --patch <patchfile>"
 	echo
 	echo "libxfs-apply should be run in the destination git repository."
@@ -67,6 +67,7 @@
 PATCH=
 COMMIT_ID=
 VERBOSE=
+IMPORT_ONLY=
 GUILT=0
 STGIT=0
 
@@ -76,6 +77,7 @@
 	--patch)	PATCH=$2; shift ;;
 	--commit)	COMMIT_ID=$2 ; shift ;;
 	--sob)		SIGNED_OFF_BY=$2 ; shift ;;
+	--import-only)	IMPORT_ONLY=true ;;
 	--verbose)	VERBOSE=true ;;
 	*)		usage ;;
 	esac
@@ -99,6 +101,10 @@
 	GUILT=1
 fi
 
+if [ -n $IMPORT_ONLY -a $GUILT -ne 1 ]; then
+	usage "--import_only can only be used with a guilt stack"
+fi
+
 # Are we using stgit? This works even if no patch is applied.
 stg top &> /dev/null
 if [ $? -eq 0 ]; then
@@ -359,6 +365,11 @@
 		fi
 
 		guilt import -P $_patch_name $_new_patch.2
+
+		if [ -n "$IMPORT_ONLY" ]; then
+			return;
+		fi
+
 		guilt push
 		if [ $? -eq 0 ]; then
 			guilt refresh
@@ -443,10 +454,17 @@
 	hashr="$hashr -- libxfs"
 fi
 
+# When using --import-only, the commit list should be in reverse order.
+if [ "$GUILT" -eq 1 -a -n "$IMPORT_ONLY" ]; then
+	commit_list=`git rev-list --no-merges $hashr`
+else
+	commit_list=`git rev-list --no-merges $hashr | tac`
+fi
+
 # grab and echo the list of commits for confirmation
 echo "Commits to apply:"
-commit_list=`git rev-list --no-merges $hashr | tac`
 git log --oneline --no-merges $hashr |tac
+
 read -r -p "Proceed [y|N]? " response
 if [ -z "$response" -o "$response" != "y" ]; then
 	fail "Aborted!"