[PATCH 13/14] pull --rebase: exit early when the working directory is dirty

[Paul Tan <pyokagan@gmail.com>]

Re-implement the behavior introduced by f9189cf (pull --rebase: exit
early when the working directory is dirty, 2008-05-21).

Signed-off-by: Paul Tan <pyokagan@gmail.com>
---
 builtin/pull.c  | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 t/t5520-pull.sh |  6 ++---
 2 files changed, 79 insertions(+), 4 deletions(-)

diff --git a/builtin/pull.c b/builtin/pull.c
index a0958a7..c8d673d 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -14,6 +14,8 @@
 #include "remote.h"
 #include "dir.h"
 #include "refs.h"
+#include "revision.h"
+#include "lockfile.h"
 
 /**
  * Given an option opt, where opt->value points to a char* and opt->defval is a
@@ -327,6 +329,73 @@ static int config_get_rebase(void)
 	return value;
 }
 
+/**
+ * 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);
+}
+
 struct known_remote {
 	struct known_remote *next;
 	struct remote *remote;
@@ -782,9 +851,15 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	if (get_sha1("HEAD", orig_head))
 		hashclr(orig_head);
 
-	if (opt_rebase)
+	if (opt_rebase) {
+		if (is_null_sha1(orig_head) && !is_cache_unborn())
+			die(_("Updating an unborn branch with changes added to the index."));
+
+		die_on_unclean_work_tree(prefix);
+
 		if (get_rebase_fork_point(rebase_fork_point, repo, *refspecs))
 			hashclr(rebase_fork_point);
+	}
 
 	if (run_fetch(repo, refspecs))
 		return 1;
diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
index 17254ee..62dbfb5 100755
--- a/t/t5520-pull.sh
+++ b/t/t5520-pull.sh
@@ -390,7 +390,7 @@ test_expect_success 'rebased upstream + fetch + pull --rebase' '
 
 '
 
-test_expect_failure 'pull --rebase dies early with dirty working directory' '
+test_expect_success 'pull --rebase dies early with dirty working directory' '
 
 	git checkout to-rebase &&
 	git update-ref refs/remotes/me/copy copy^ &&
@@ -420,7 +420,7 @@ test_expect_success 'pull --rebase works on branch yet to be born' '
 	test_cmp expect actual
 '
 
-test_expect_failure 'pull --rebase fails on unborn branch with staged changes' '
+test_expect_success 'pull --rebase fails on unborn branch with staged changes' '
 	test_when_finished "rm -rf empty_repo2" &&
 	git init empty_repo2 &&
 	(
@@ -492,7 +492,7 @@ test_expect_success 'git pull --rebase does not reapply old patches' '
 	)
 '
 
-test_expect_failure 'git pull --rebase against local branch' '
+test_expect_success 'git pull --rebase against local branch' '
 	git checkout -b copy2 to-rebase-orig &&
 	git pull --rebase . to-rebase &&
 	test "conflicting modification" = "$(cat file)" &&
-- 
2.1.4