[WIP PATCH 14/22] Make rewrite_parents public to other part of git

[Bo Yang <struggleyb.nku@gmail.com>]

The function rewrite_one is used to rewrite a single
parent of the current commit, and is used by rewrite_parents
to rewrite all the parents.

Decouple the dependence between them by making rewrite_one
a callback function that is passed to rewrite_parents. Then
export rewrite_parents for reuse by the line history browser.

We will use this function in line.c.

Signed-off-by: Bo Yang <struggleyb.nku@gmail.com>
---
 revision.c |   13 ++++---------
 revision.h |   10 ++++++++++
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/revision.c b/revision.c
index 25c9a94..fb08978 100644
--- a/revision.c
+++ b/revision.c
@@ -1893,12 +1893,6 @@ int prepare_revision_walk(struct rev_info *revs)
 	return 0;
 }
 
-enum rewrite_result {
-	rewrite_one_ok,
-	rewrite_one_noparents,
-	rewrite_one_error
-};
-
 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
 {
 	struct commit_list *cache = NULL;
@@ -1920,12 +1914,13 @@ static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp
 	}
 }
 
-static int rewrite_parents(struct rev_info *revs, struct commit *commit)
+int rewrite_parents(struct rev_info *revs, struct commit *commit,
+	rewrite_parent_fn_t rewrite_parent)
 {
 	struct commit_list **pp = &commit->parents;
 	while (*pp) {
 		struct commit_list *parent = *pp;
-		switch (rewrite_one(revs, &parent->item)) {
+		switch (rewrite_parent(revs, &parent->item)) {
 		case rewrite_one_ok:
 			break;
 		case rewrite_one_noparents:
@@ -1993,7 +1988,7 @@ enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
 	if (action == commit_show &&
 	    !revs->show_all &&
 	    revs->prune && revs->dense && want_ancestry(revs)) {
-		if (rewrite_parents(revs, commit) < 0)
+		if (rewrite_parents(revs, commit, rewrite_one) < 0)
 			return commit_error;
 	}
 	return action;
diff --git a/revision.h b/revision.h
index e4b6adf..e625c3d 100644
--- a/revision.h
+++ b/revision.h
@@ -200,4 +200,14 @@ enum commit_action {
 extern enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit);
 extern enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit);
 
+enum rewrite_result {
+	rewrite_one_ok,
+	rewrite_one_noparents,
+	rewrite_one_error
+};
+
+typedef enum rewrite_result (*rewrite_parent_fn_t)(struct rev_info *revs, struct commit **pp);
+
+extern int rewrite_parents(struct rev_info *revs, struct commit *commit,
+	rewrite_parent_fn_t rewrite_parent);
 #endif
-- 
1.7.0.2.273.gc2413.dirty