From cd541a68b38cead87f5fa69d5331c467bce71656 Mon Sep 17 00:00:00 2001
From: Daniel Barkalow <barkalow@iabervon.org>
Date: Mon, 6 Jun 2005 16:38:26 -0400
Subject: [PATCH] [PATCH] Generic support for pulling refs

This adds support to pull.c for requesting a reference and writing it to a
file. All of the git-*-pull programs get stubs for now.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 http-pull.c  |  5 +++++
 local-pull.c |  5 +++++
 pull.c       | 49 ++++++++++++++++++++++++++++++++++++++++---------
 pull.h       |  8 ++++++++
 ssh-pull.c   |  5 +++++
 5 files changed, 63 insertions(+), 9 deletions(-)

diff --git a/http-pull.c b/http-pull.c
index ec7f66af8f..f49525c002 100644
--- a/http-pull.c
+++ b/http-pull.c
@@ -92,6 +92,11 @@ int fetch(unsigned char *sha1)
 	return 0;
 }
 
+int fetch_ref(char *ref, unsigned char *sha1)
+{
+	return -1;
+}
+
 int main(int argc, char **argv)
 {
 	char *commit_id;
diff --git a/local-pull.c b/local-pull.c
index afdba9f527..8bfe67b407 100644
--- a/local-pull.c
+++ b/local-pull.c
@@ -73,6 +73,11 @@ int fetch(unsigned char *sha1)
 	return -1;
 }
 
+int fetch_ref(char *ref, unsigned char *sha1)
+{
+	return -1;
+}
+
 static const char *local_pull_usage = 
 "git-local-pull [-c] [-t] [-a] [-l] [-s] [-n] [-v] [-d] [--recover] commit-id path";
 
diff --git a/pull.c b/pull.c
index f4f1d8fcd3..395ca45328 100644
--- a/pull.c
+++ b/pull.c
@@ -3,6 +3,11 @@
 #include "cache.h"
 #include "commit.h"
 #include "tree.h"
+#include "refs.h"
+
+const char *write_ref = NULL;
+
+const unsigned char *current_ref = NULL;
 
 int get_tree = 0;
 int get_history = 0;
@@ -110,16 +115,42 @@ static int process_commit(unsigned char *sha1)
 	return 0;
 }
 
+static int interpret_target(char *target, unsigned char *sha1)
+{
+	if (!get_sha1_hex(target, sha1))
+		return 0;
+	if (!check_ref_format(target)) {
+		if (!fetch_ref(target, sha1)) {
+			return 0;
+		}
+	}
+	return -1;
+}
+
+
 int pull(char *target)
 {
-	int retval;
 	unsigned char sha1[20];
-	retval = get_sha1_hex(target, sha1);
-	if (retval)
-		return retval;
-	retval = make_sure_we_have_it(commitS, sha1);
-	if (retval)
-		return retval;
-	memcpy(current_commit_sha1, sha1, 20);
-	return process_commit(sha1);
+	int fd = -1;
+
+	if (write_ref && current_ref) {
+		fd = lock_ref_sha1(write_ref, current_ref);
+		if (fd < 0)
+			return -1;
+	}
+
+	if (interpret_target(target, sha1))
+		return error("Could not interpret %s as something to pull",
+			     target);
+	if (process_commit(sha1))
+		return -1;
+	
+	if (write_ref) {
+		if (current_ref) {
+			write_ref_sha1(write_ref, fd, sha1);
+		} else {
+			write_ref_sha1_unlocked(write_ref, sha1);
+		}
+	}
+	return 0;
 }
diff --git a/pull.h b/pull.h
index 30086fdb12..bd5e7bdeb3 100644
--- a/pull.h
+++ b/pull.h
@@ -4,6 +4,14 @@
 /** To be provided by the particular implementation. **/
 extern int fetch(unsigned char *sha1);
 
+extern int fetch_ref(char *ref, unsigned char *sha1);
+
+/** If set, the ref filename to write the target value to. **/
+extern const char *write_ref;
+
+/** If set, the hash that the current value of write_ref must be. **/
+extern const unsigned char *current_ref;
+
 /** Set to fetch the target tree. */
 extern int get_tree;
 
diff --git a/ssh-pull.c b/ssh-pull.c
index 3556d89a33..a426342590 100644
--- a/ssh-pull.c
+++ b/ssh-pull.c
@@ -39,6 +39,11 @@ int get_version(void)
 	return 0;
 }
 
+int fetch_ref(char *ref, unsigned char *sha1)
+{
+	return -1;
+}
+
 int main(int argc, char **argv)
 {
 	char *commit_id;
-- 
2.11.4.GIT