1 files changed, 21 insertions, 72 deletions

diff --git a/builtin/pull.c b/builtin/pull.c
index 398aae16c0..3ecb881b0b 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -17,6 +17,7 @@
 #include "revision.h"
 #include "tempfile.h"
 #include "lockfile.h"
+#include "wt-status.h"
 
 enum rebase_type {
 	REBASE_INVALID = -1,
@@ -326,73 +327,6 @@ static int git_pull_config(const char *var, const char *value, void *cb)
 }
 
 /**
- * Returns 1 if there are unstaged changes, 0 otherwise.
- */
-static int has_unstaged_changes(const char *prefix)
-{
-	struct rev_info rev_info;
-	int result;
-
-	init_revisions(&rev_info, prefix);
-	DIFF_OPT_SET(&rev_info.diffopt, IGNORE_SUBMODULES);
-	DIFF_OPT_SET(&rev_info.diffopt, QUICK);
-	diff_setup_done(&rev_info.diffopt);
-	result = run_diff_files(&rev_info, 0);
-	return diff_result_code(&rev_info.diffopt, result);
-}
-
-/**
- * Returns 1 if there are uncommitted changes, 0 otherwise.
- */
-static int has_uncommitted_changes(const char *prefix)
-{
-	struct rev_info rev_info;
-	int result;
-
-	if (is_cache_unborn())
-		return 0;
-
-	init_revisions(&rev_info, prefix);
-	DIFF_OPT_SET(&rev_info.diffopt, IGNORE_SUBMODULES);
-	DIFF_OPT_SET(&rev_info.diffopt, QUICK);
-	add_head_to_pending(&rev_info);
-	diff_setup_done(&rev_info.diffopt);
-	result = run_diff_index(&rev_info, 1);
-	return diff_result_code(&rev_info.diffopt, result);
-}
-
-/**
- * If the work tree has unstaged or uncommitted changes, dies with the
- * appropriate message.
- */
-static void die_on_unclean_work_tree(const char *prefix)
-{
-	struct lock_file *lock_file = xcalloc(1, sizeof(*lock_file));
-	int do_die = 0;
-
-	hold_locked_index(lock_file, 0);
-	refresh_cache(REFRESH_QUIET);
-	update_index_if_able(&the_index, lock_file);
-	rollback_lock_file(lock_file);
-
-	if (has_unstaged_changes(prefix)) {
-		error(_("Cannot pull with rebase: You have unstaged changes."));
-		do_die = 1;
-	}
-
-	if (has_uncommitted_changes(prefix)) {
-		if (do_die)
-			error(_("Additionally, your index contains uncommitted changes."));
-		else
-			error(_("Cannot pull with rebase: Your index contains uncommitted changes."));
-		do_die = 1;
-	}
-
-	if (do_die)
-		exit(1);
-}
-
-/**
  * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
  * into merge_heads.
  */
@@ -875,7 +809,8 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 			die(_("Updating an unborn branch with changes added to the index."));
 
 		if (!autostash)
-			die_on_unclean_work_tree(prefix);
+			require_clean_work_tree(N_("pull with rebase"),
+				_("please commit or stash them."), 1, 0);
 
 		if (get_rebase_fork_point(rebase_fork_point, repo, *refspecs))
 			hashclr(rebase_fork_point);
@@ -922,10 +857,24 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 		if (merge_heads.nr > 1)
 			die(_("Cannot merge multiple branches into empty head."));
 		return pull_into_void(*merge_heads.sha1, curr_head);
-	} else if (opt_rebase) {
-		if (merge_heads.nr > 1)
-			die(_("Cannot rebase onto multiple branches."));
+	}
+	if (opt_rebase && merge_heads.nr > 1)
+		die(_("Cannot rebase onto multiple branches."));
+
+	if (opt_rebase) {
+		struct commit_list *list = NULL;
+		struct commit *merge_head, *head;
+
+		head = lookup_commit_reference(orig_head);
+		commit_list_insert(head, &list);
+		merge_head = lookup_commit_reference(merge_heads.sha1[0]);
+		if (is_descendant_of(merge_head, list)) {
+			/* we can fast-forward this without invoking rebase */
+			opt_ff = "--ff-only";
+			return run_merge();
+		}
 		return run_rebase(curr_head, *merge_heads.sha1, rebase_fork_point);
-	} else
+	} else {
 		return run_merge();
+	}
 }