Merge branch 'bc/repack'

* bc/repack:
  Documentation/git-repack.txt: document new -A behaviour
  let pack-objects do the writing of unreachable objects as loose objects
  add a force_object_loose() function
  builtin-gc.c: deprecate --prune, it now really has no effect
  git-gc: always use -A when manually repacking
  repack: modify behavior of -A option to leave unreferenced objects unpacked

Conflicts:

	builtin-pack-objects.c

7 files changed, 154 insertions, 34 deletions

diff --git a/Documentation/git-repack.txt b/Documentation/git-repack.txt
index d14ab5154f..f81a6607de 100644
--- a/Documentation/git-repack.txt
+++ b/Documentation/git-repack.txt
@@ -8,7 +8,7 @@ git-repack - Pack unpacked objects in a repository
 
 SYNOPSIS
 --------
-'git-repack' [-a] [-d] [-f] [-l] [-n] [-q] [--window=N] [--depth=N]
+'git-repack' [-a] [-A] [-d] [-f] [-l] [-n] [-q] [--window=N] [--depth=N]
 
 DESCRIPTION
 -----------
@@ -37,6 +37,18 @@ OPTIONS
 	leaves behind, but `git fsck --full` shows as
 	dangling.
 
+-A::
+	Same as `-a`, but any unreachable objects in a previous
+	pack become loose, unpacked objects, instead of being
+	left in the old pack.  Unreachable objects are never
+	intentionally added to a pack, even when repacking.
+	When used with '-d', this option
+	prevents unreachable objects from being immediately
+	deleted by way of being left in the old pack and then
+	removed.  Instead, the loose unreachable objects
+	will be pruned according to normal expiry rules
+	with the next linkgit:git-gc[1].
+
 -d::
 	After packing, if the newly created packs make some
 	existing packs redundant, remove the redundant packs.
diff --git a/builtin-gc.c b/builtin-gc.c
index f99ebc7926..48f7d95f97 100644
--- a/builtin-gc.c
+++ b/builtin-gc.c
@@ -219,7 +219,7 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 	char buf[80];
 
 	struct option builtin_gc_options[] = {
-		OPT_BOOLEAN(0, "prune", &prune, "prune unreferenced objects"),
+		OPT_BOOLEAN(0, "prune", &prune, "prune unreferenced objects (deprecated)"),
 		OPT_BOOLEAN(0, "aggressive", &aggressive, "be more thorough (increased runtime)"),
 		OPT_BOOLEAN(0, "auto", &auto_gc, "enable auto-gc mode"),
 		OPT_BOOLEAN('q', "quiet", &quiet, "suppress progress reports"),
@@ -249,24 +249,14 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 		/*
 		 * Auto-gc should be least intrusive as possible.
 		 */
-		prune = 0;
 		if (!need_to_gc())
 			return 0;
 		fprintf(stderr, "Auto packing your repository for optimum "
 			"performance. You may also\n"
 			"run \"git gc\" manually. See "
 			"\"git help gc\" for more information.\n");
-	} else {
-		/*
-		 * Use safer (for shared repos) "-A" option to
-		 * repack when not pruning. Auto-gc makes its
-		 * own decision.
-		 */
-		if (prune)
-			append_option(argv_repack, "-a", MAX_ADD);
-		else
-			append_option(argv_repack, "-A", MAX_ADD);
-	}
+	} else
+		append_option(argv_repack, "-A", MAX_ADD);
 
 	if (pack_refs && run_command_v_opt(argv_pack_refs, RUN_GIT_CMD))
 		return error(FAILED_RUN, argv_pack_refs[0]);
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index e20851e1c9..f43eb67016 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -28,7 +28,8 @@ git-pack-objects [{ -q | --progress | --all-progress }] \n\
 	[--window=N] [--window-memory=N] [--depth=N] \n\
 	[--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
 	[--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
-	[--stdout | base-name] [--include-tag] [--keep-unreachable] \n\
+	[--stdout | base-name] [--include-tag] \n\
+	[--keep-unreachable | --unpack-unreachable] \n\
 	[<ref-list | <object-list]";
 
 struct object_entry {
@@ -67,7 +68,7 @@ static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
 
 static int non_empty;
 static int reuse_delta = 1, reuse_object = 1;
-static int keep_unreachable, include_tag;
+static int keep_unreachable, unpack_unreachable, include_tag;
 static int local;
 static int incremental;
 static int allow_ofs_delta;
@@ -1946,6 +1947,32 @@ static void add_objects_in_unpacked_packs(struct rev_info *revs)
 	free(in_pack.array);
 }
 
+static void loosen_unused_packed_objects(struct rev_info *revs)
+{
+	struct packed_git *p;
+	uint32_t i;
+	const unsigned char *sha1;
+
+	for (p = packed_git; p; p = p->next) {
+		for (i = 0; i < revs->num_ignore_packed; i++) {
+			if (matches_pack_name(p, revs->ignore_packed[i]))
+				break;
+		}
+		if (revs->num_ignore_packed <= i)
+			continue;
+
+		if (open_pack_index(p))
+			die("cannot open pack index");
+
+		for (i = 0; i < p->num_objects; i++) {
+			sha1 = nth_packed_object_sha1(p, i);
+			if (!locate_object_entry(sha1))
+				if (force_object_loose(sha1, p->mtime))
+					die("unable to force loose object");
+		}
+	}
+}
+
 static void get_object_list(int ac, const char **av)
 {
 	struct rev_info revs;
@@ -1980,6 +2007,8 @@ static void get_object_list(int ac, const char **av)
 
 	if (keep_unreachable)
 		add_objects_in_unpacked_packs(&revs);
+	if (unpack_unreachable)
+		loosen_unused_packed_objects(&revs);
 }
 
 static int adjust_perm(const char *path, mode_t mode)
@@ -2114,6 +2143,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			keep_unreachable = 1;
 			continue;
 		}
+		if (!strcmp("--unpack-unreachable", arg)) {
+			unpack_unreachable = 1;
+			continue;
+		}
 		if (!strcmp("--include-tag", arg)) {
 			include_tag = 1;
 			continue;
@@ -2179,6 +2212,9 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	if (!pack_to_stdout && thin)
 		die("--thin cannot be used to build an indexable pack.");
 
+	if (keep_unreachable && unpack_unreachable)
+		die("--keep-unreachable and --unpack-unreachable are incompatible.");
+
 #ifdef THREADED_DELTA_SEARCH
 	if (!delta_search_threads)	/* --threads=0 means autodetect */
 		delta_search_threads = online_cpus();
diff --git a/cache.h b/cache.h
index 0f89f1569a..8db19cc253 100644
--- a/cache.h
+++ b/cache.h
@@ -521,6 +521,7 @@ extern void * read_sha1_file(const unsigned char *sha1, enum object_type *type,
 extern int hash_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1);
 extern int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
 extern int pretend_sha1_file(void *, unsigned long, enum object_type, unsigned char *);
+extern int force_object_loose(const unsigned char *sha1, time_t mtime);
 
 extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
 
diff --git a/git-repack.sh b/git-repack.sh
index 501519ab68..10f735cff5 100755
--- a/git-repack.sh
+++ b/git-repack.sh
@@ -8,7 +8,7 @@ OPTIONS_SPEC="\
 git-repack [options]
 --
 a               pack everything in a single pack
-A               same as -a, and keep unreachable objects too
+A               same as -a, and turn unreachable objects loose
 d               remove redundant packs, and run git-prune-packed
 f               pass --no-reuse-delta to git-pack-objects
 n               do not run git-update-server-info
@@ -23,7 +23,7 @@ max-pack-size=  maximum size of each packfile
 SUBDIRECTORY_OK='Yes'
 . git-sh-setup
 
-no_update_info= all_into_one= remove_redundant= keep_unreachable=
+no_update_info= all_into_one= remove_redundant= unpack_unreachable=
 local= quiet= no_reuse= extra=
 while test $# != 0
 do
@@ -31,7 +31,7 @@ do
 	-n)	no_update_info=t ;;
 	-a)	all_into_one=t ;;
 	-A)	all_into_one=t
-		keep_unreachable=--keep-unreachable ;;
+		unpack_unreachable=--unpack-unreachable ;;
 	-d)	remove_redundant=t ;;
 	-q)	quiet=-q ;;
 	-f)	no_reuse=--no-reuse-object ;;
@@ -79,9 +79,9 @@ case ",$all_into_one," in
 	if test -z "$args"
 	then
 		args='--unpacked --incremental'
-	elif test -n "$keep_unreachable"
+	elif test -n "$unpack_unreachable"
 	then
-		args="$args $keep_unreachable"
+		args="$args $unpack_unreachable"
 	fi
 	;;
 esac
diff --git a/sha1_file.c b/sha1_file.c
index 3516777bc7..141f5a713a 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -2102,26 +2102,16 @@ int hash_sha1_file(const void *buf, unsigned long len, const char *type,
 	return 0;
 }
 
-int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
+static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
+			      void *buf, unsigned long len, time_t mtime)
 {
-	int size, ret;
+	int fd, size, ret;
 	unsigned char *compressed;
 	z_stream stream;
-	unsigned char sha1[20];
 	char *filename;
 	static char tmpfile[PATH_MAX];
-	char hdr[32];
-	int fd, hdrlen;
 
-	/* Normally if we have it in the pack then we do not bother writing
-	 * it out into .git/objects/??/?{38} file.
-	 */
-	write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
 	filename = sha1_file_name(sha1);
-	if (returnsha1)
-		hashcpy(returnsha1, sha1);
-	if (has_sha1_file(sha1))
-		return 0;
 	fd = open(filename, O_RDONLY);
 	if (fd >= 0) {
 		/*
@@ -2182,9 +2172,53 @@ int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned cha
 		die("unable to write sha1 file");
 	free(compressed);
 
+	if (mtime) {
+		struct utimbuf utb;
+		utb.actime = mtime;
+		utb.modtime = mtime;
+		if (utime(tmpfile, &utb) < 0)
+			warning("failed utime() on %s: %s",
+				tmpfile, strerror(errno));
+	}
+
 	return move_temp_to_file(tmpfile, filename);
 }
 
+int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
+{
+	unsigned char sha1[20];
+	char hdr[32];
+	int hdrlen;
+
+	/* Normally if we have it in the pack then we do not bother writing
+	 * it out into .git/objects/??/?{38} file.
+	 */
+	write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
+	if (returnsha1)
+		hashcpy(returnsha1, sha1);
+	if (has_sha1_file(sha1))
+		return 0;
+	return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
+}
+
+int force_object_loose(const unsigned char *sha1, time_t mtime)
+{
+	struct stat st;
+	void *buf;
+	unsigned long len;
+	enum object_type type;
+	char hdr[32];
+	int hdrlen;
+
+	if (find_sha1_file(sha1, &st))
+		return 0;
+	buf = read_packed_sha1(sha1, &type, &len);
+	if (!buf)
+		return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
+	hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
+	return write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
+}
+
 /*
  * We need to unpack and recompress the object for writing
  * it out to a different file.
diff --git a/t/t7701-repack-unpack-unreachable.sh b/t/t7701-repack-unpack-unreachable.sh
new file mode 100755
index 0000000000..6a5211f187
--- /dev/null
+++ b/t/t7701-repack-unpack-unreachable.sh
@@ -0,0 +1,47 @@
+#!/bin/sh
+
+test_description='git-repack works correctly'
+
+. ./test-lib.sh
+
+test_expect_success '-A option leaves unreachable objects unpacked' '
+	echo content > file1 &&
+	git add . &&
+	git commit -m initial_commit &&
+	# create a transient branch with unique content
+	git checkout -b transient_branch &&
+	echo more content >> file1 &&
+	# record the objects created in the database for file, commit, tree
+	fsha1=$(git hash-object file1) &&
+	git commit -a -m more_content &&
+	csha1=$(git rev-parse HEAD^{commit}) &&
+	tsha1=$(git rev-parse HEAD^{tree}) &&
+	git checkout master &&
+	echo even more content >> file1 &&
+	git commit -a -m even_more_content &&
+	# delete the transient branch
+	git branch -D transient_branch &&
+	# pack the repo
+	git repack -A -d -l &&
+	# verify objects are packed in repository
+	test 3 = $(git verify-pack -v -- .git/objects/pack/*.idx |
+		   grep -e "^$fsha1 " -e "^$csha1 " -e "^$tsha1 " |
+		   sort | uniq | wc -l) &&
+	git show $fsha1 &&
+	git show $csha1 &&
+	git show $tsha1 &&
+	# now expire the reflog
+	sleep 1 &&
+	git reflog expire --expire-unreachable=now --all &&
+	# and repack
+	git repack -A -d -l &&
+	# verify objects are retained unpacked
+	test 0 = $(git verify-pack -v -- .git/objects/pack/*.idx |
+		   grep -e "^$fsha1 " -e "^$csha1 " -e "^$tsha1 " |
+		   sort | uniq | wc -l) &&
+	git show $fsha1 &&
+	git show $csha1 &&
+	git show $tsha1
+'
+
+test_done