[PATCH/RFC 1/2] fetch-pack: new option to read refs from stdin

[Ivan Todoroski <grnch_lists@gmx.net>]

>From c4bb55f9f27569faa368d823ca6fe4b236e37cd6 Mon Sep 17 00:00:00 2001
From: Ivan Todoroski <grnch@gmx.net>
Date: Sat, 24 Mar 2012 15:13:05 +0100
Subject: [PATCH/RFC 1/2] fetch-pack: new option to read refs from stdin

---
 Documentation/git-fetch-pack.txt |    9 ++++++++
 builtin/fetch-pack.c             |   44 ++++++++++++++++++++++++++++++++++++--
 fetch-pack.h                     |    3 ++-
 3 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/Documentation/git-fetch-pack.txt b/Documentation/git-fetch-pack.txt
index ed1bdaacd1..7cd7c785bc 100644
--- a/Documentation/git-fetch-pack.txt
+++ b/Documentation/git-fetch-pack.txt
@@ -32,6 +32,15 @@ OPTIONS
 --all::
 	Fetch all remote refs.
 
+--stdin::
+	Take the list of refs from stdin, one per line. If there
+	are refs specified on the command line in addition to this
+	option, then the refs from stdin are processed after those
+	on the command line.
+	If '--stateless-rpc' is specified together with this option
+	then the list of refs must be in packet format (pkt-line)
+	with a flush packet terminating the list.
+
 -q::
 --quiet::
 	Pass '-q' flag to 'git unpack-objects'; this makes the
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index a4d3e90a86..3c4c193e45 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -23,7 +23,7 @@ static struct fetch_pack_args args = {
 };
 
 static const char fetch_pack_usage[] =
-"git fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
+"git fetch-pack [--all] [--stdin] [--quiet|-q] [--keep|-k] [--thin] [--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
 
 #define COMPLETE	(1U << 0)
 #define COMMON		(1U << 1)
@@ -896,7 +896,7 @@ static void fetch_pack_setup(void)
 
 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 {
-	int i, ret, nr_heads;
+	int i, ret, nr_heads, alloc_heads;
 	struct ref *ref = NULL;
 	char *dest = NULL, **heads;
 	int fd[2];
@@ -941,6 +941,10 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 				args.fetch_all = 1;
 				continue;
 			}
+			if (!strcmp("--stdin", arg)) {
+				args.refs_from_stdin = 1;
+				continue;
+			}
 			if (!strcmp("-v", arg)) {
 				args.verbose = 1;
 				continue;
@@ -972,6 +976,42 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 	if (!dest)
 		usage(fetch_pack_usage);
 
+	if (args.refs_from_stdin) {
+		char ref[1000];
+		/* copy refs from cmdline to new growable list */
+		int size = nr_heads * sizeof(*heads);
+		heads = memcpy(xmalloc(size), heads, size);
+		alloc_heads = nr_heads;
+		/* append refs from stdin to ones from cmdline */
+		for (;;) {
+			if (args.stateless_rpc) {
+				/* read using pkt-line in stateless RPC mode,
+				   flush packet signifies end of refs */
+				int n = packet_read_line(0, ref, sizeof(ref));
+				if (!n)
+					break;
+				if (ref[n-1] == '\n')
+					ref[n-1] = '\0';
+			}
+			else {
+				int n;
+				if (!fgets(ref, sizeof(ref), stdin)) {
+					if (ferror(stdin))
+						die_errno("cannot read ref");
+					if (feof(stdin))
+						break;
+				}
+				n = strlen(ref);
+				if (ref[n-1] == '\n')
+					ref[n-1] = '\0';
+				else if (!feof(stdin))
+					die("ref too long on stdin");
+			}
+			ALLOC_GROW(heads, nr_heads + 1, alloc_heads);
+			heads[nr_heads++] = xstrdup(ref);
+		}
+	}
+
 	if (args.stateless_rpc) {
 		conn = NULL;
 		fd[0] = 0;
diff --git a/fetch-pack.h b/fetch-pack.h
index 0608edae3f..292d69389e 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h
@@ -13,7 +13,8 @@ struct fetch_pack_args {
 		verbose:1,
 		no_progress:1,
 		include_tag:1,
-		stateless_rpc:1;
+		stateless_rpc:1,
+		refs_from_stdin:1;
 };
 
 struct ref *fetch_pack(struct fetch_pack_args *args,
-- 
1.7.9.4.16.gd24fa.dirty