[PATCH v3 4/9] revert: refactor checking parent in a check_parent() function

[Christian Couder <chriscool@tuxfamily.org>]

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 builtin/revert.c |   62 ++++++++++++++++++++++++++++++-----------------------
 1 files changed, 35 insertions(+), 27 deletions(-)

diff --git a/builtin/revert.c b/builtin/revert.c
index eff5268..a611960 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -244,6 +244,40 @@ static NORETURN void die_dirty_index(const char *me)
 	}
 }
 
+static struct commit * check_parent(struct commit *commit, int mainline)
+{
+	if (!commit->parents) {
+		if (action == REVERT)
+			die ("Cannot revert a root commit");
+		return NULL;
+	}
+
+	if (commit->parents->next) {
+		/* Reverting or cherry-picking a merge commit */
+		int cnt;
+		struct commit_list *p;
+
+		if (!mainline)
+			die("Commit %s is a merge but no -m option was given.",
+			    sha1_to_hex(commit->object.sha1));
+
+		for (cnt = 1, p = commit->parents;
+		     cnt != mainline && p;
+		     cnt++)
+			p = p->next;
+		if (cnt != mainline || !p)
+			die("Commit %s does not have parent %d",
+			    sha1_to_hex(commit->object.sha1), mainline);
+		return p->item;
+	}
+
+	if (0 < mainline)
+		die("Mainline was specified but commit %s is not a merge.",
+		    sha1_to_hex(commit->object.sha1));
+
+	return commit->parents->item;
+}
+
 static int revert_or_cherry_pick(int argc, const char **argv)
 {
 	unsigned char head[20];
@@ -286,33 +320,7 @@ static int revert_or_cherry_pick(int argc, const char **argv)
 
 	index_fd = hold_locked_index(&index_lock, 1);
 
-	if (!commit->parents) {
-		if (action == REVERT)
-			die ("Cannot revert a root commit");
-		parent = NULL;
-	}
-	else if (commit->parents->next) {
-		/* Reverting or cherry-picking a merge commit */
-		int cnt;
-		struct commit_list *p;
-
-		if (!mainline)
-			die("Commit %s is a merge but no -m option was given.",
-			    sha1_to_hex(commit->object.sha1));
-
-		for (cnt = 1, p = commit->parents;
-		     cnt != mainline && p;
-		     cnt++)
-			p = p->next;
-		if (cnt != mainline || !p)
-			die("Commit %s does not have parent %d",
-			    sha1_to_hex(commit->object.sha1), mainline);
-		parent = p->item;
-	} else if (0 < mainline)
-		die("Mainline was specified but commit %s is not a merge.",
-		    sha1_to_hex(commit->object.sha1));
-	else
-		parent = commit->parents->item;
+	parent = check_parent(commit, mainline);
 
 	if (!(message = commit->buffer))
 		die ("Cannot get commit message for %s",
-- 
1.7.0.315.gbc198