[PATCH/RFC/GSoC 09/17] rebase-common: implement cache_has_unstaged_changes()

[Paul Tan <pyokagan@gmail.com>]

In the upcoming git-rebase-to-C rewrite, it is a common operation to
check if the worktree has unstaged changes, so that it can complain that
the worktree is dirty.

builtin/pull.c already implements this function. Move it to
rebase-common.c so that it can be shared between all rebase backends and
git-pull.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
---
 builtin/pull.c  | 19 ++-----------------
 rebase-common.c | 14 ++++++++++++++
 rebase-common.h |  5 +++++
 3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/builtin/pull.c b/builtin/pull.c
index 10eff03..9e65dc9 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -17,6 +17,7 @@
 #include "revision.h"
 #include "tempfile.h"
 #include "lockfile.h"
+#include "rebase-common.h"
 
 enum rebase_type {
 	REBASE_INVALID = -1,
@@ -306,22 +307,6 @@ static enum rebase_type config_get_rebase(void)
 }
 
 /**
- * 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)
@@ -355,7 +340,7 @@ static void die_on_unclean_work_tree(const char *prefix)
 	update_index_if_able(&the_index, lock_file);
 	rollback_lock_file(lock_file);
 
-	if (has_unstaged_changes(prefix)) {
+	if (cache_has_unstaged_changes()) {
 		error(_("Cannot pull with rebase: You have unstaged changes."));
 		do_die = 1;
 	}
diff --git a/rebase-common.c b/rebase-common.c
index 97b0687..61be8f1 100644
--- a/rebase-common.c
+++ b/rebase-common.c
@@ -4,6 +4,7 @@
 #include "run-command.h"
 #include "refs.h"
 #include "lockfile.h"
+#include "revision.h"
 
 void refresh_and_write_cache(unsigned int flags)
 {
@@ -15,6 +16,19 @@ void refresh_and_write_cache(unsigned int flags)
 		die(_("unable to write index file"));
 }
 
+int cache_has_unstaged_changes(void)
+{
+	struct rev_info rev_info;
+	int result;
+
+	init_revisions(&rev_info, NULL);
+	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);
+}
+
 void rebase_options_init(struct rebase_options *opts)
 {
 	oidclr(&opts->onto);
diff --git a/rebase-common.h b/rebase-common.h
index 4586f03..9d14e25 100644
--- a/rebase-common.h
+++ b/rebase-common.h
@@ -6,6 +6,11 @@
  */
 void refresh_and_write_cache(unsigned int);
 
+/**
+ * Returns 1 if there are unstaged changes, 0 otherwise.
+ */
+int cache_has_unstaged_changes(void);
+
 /* common rebase backend options */
 struct rebase_options {
 	struct object_id onto;
-- 
2.7.0