Merge branch 'js/clone-dissociate' into maint

"git clone --dissociate" runs a big "git repack" process at the
end, and it helps to close file descriptors that are open on the
packs and their idx files before doing so on filesystems that
cannot remove a file that is still open.

* js/clone-dissociate:
  clone --dissociate: avoid locking pack files
  sha1_file.c: add a function to release all packs
  sha1_file: consolidate code to close a pack's file descriptor
  t5700: demonstrate a Windows file locking issue with `git clone --dissociate`

Author: gitster

builtin/clone.c

@@ -1064,8 +1064,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	transport_unlock_pack(transport);
 	transport_disconnect(transport);
 
-	if (option_dissociate)
+	if (option_dissociate) {
+		close_all_packs();
 		dissociate_from_references();
+	}
 
 	junk_mode = JUNK_LEAVE_REPO;
 	err = checkout();

cache.h

@@ -1282,6 +1282,7 @@ extern void close_pack_index(struct packed_git *);
 
 extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, unsigned long *);
 extern void close_pack_windows(struct packed_git *);
+extern void close_all_packs(void);
 extern void unuse_pack(struct pack_window **);
 extern void free_pack_by_name(const char *);
 extern void clear_delta_base_cache(void);

sha1_file.c

@@ -786,6 +786,37 @@ void close_pack_windows(struct packed_git *p)
 	}
 }
 
+static int close_pack_fd(struct packed_git *p)
+{
+	if (p->pack_fd < 0)
+		return 0;
+
+	close(p->pack_fd);
+	pack_open_fds--;
+	p->pack_fd = -1;
+
+	return 1;
+}
+
+static void close_pack(struct packed_git *p)
+{
+	close_pack_windows(p);
+	close_pack_fd(p);
+	close_pack_index(p);
+}
+
+void close_all_packs(void)
+{
+	struct packed_git *p;
+
+	for (p = packed_git; p; p = p->next)
+		if (p->do_not_close)
+			die("BUG! Want to close pack marked 'do-not-close'");
+		else
+			close_pack(p);
+}
+
+
 /*
  * The LRU pack is the one with the oldest MRU window, preferring packs
  * with no used windows, or the oldest mtime if it has no windows allocated.
@@ -853,12 +884,8 @@ static int close_one_pack(void)
 		find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
 	}
 
-	if (lru_p) {
-		close(lru_p->pack_fd);
-		pack_open_fds--;
-		lru_p->pack_fd = -1;
-		return 1;
-	}
+	if (lru_p)
+		return close_pack_fd(lru_p);
 
 	return 0;
 }
@@ -898,12 +925,7 @@ void free_pack_by_name(const char *pack_name)
 		p = *pp;
 		if (strcmp(pack_name, p->pack_name) == 0) {
 			clear_delta_base_cache();
-			close_pack_windows(p);
-			if (p->pack_fd != -1) {
-				close(p->pack_fd);
-				pack_open_fds--;
-			}
-			close_pack_index(p);
+			close_pack(p);
 			free(p->bad_object_sha1);
 			*pp = p->next;
 			if (last_found_pack == p)
@@ -1037,11 +1059,7 @@ static int open_packed_git(struct packed_git *p)
 {
 	if (!open_packed_git_1(p))
 		return 0;
-	if (p->pack_fd != -1) {
-		close(p->pack_fd);
-		pack_open_fds--;
-		p->pack_fd = -1;
-	}
+	close_pack_fd(p);
 	return -1;
 }
 
@@ -1107,11 +1125,8 @@ unsigned char *use_pack(struct packed_git *p,
 					p->pack_name,
 					strerror(errno));
 			if (!win->offset && win->len == p->pack_size
-				&& !p->do_not_close) {
-				close(p->pack_fd);
-				pack_open_fds--;
-				p->pack_fd = -1;
-			}
+				&& !p->do_not_close)
+				close_pack_fd(p);
 			pack_mmap_calls++;
 			pack_open_windows++;
 			if (pack_mapped > peak_pack_mapped)

t/t5700-clone-reference.sh

@@ -188,5 +188,26 @@ test_expect_success 'clone and dissociate from reference' '
 	test_must_fail git -C R fsck &&
 	git -C S fsck
 '
+test_expect_success 'clone, dissociate from partial reference and repack' '
+	rm -fr P Q R &&
+	git init P &&
+	(
+		cd P &&
+		test_commit one &&
+		git repack &&
+		test_commit two &&
+		git repack
+	) &&
+	git clone --bare P Q &&
+	(
+		cd P &&
+		git checkout -b second &&
+		test_commit three &&
+		git repack
+	) &&
+	git clone --bare --dissociate --reference=P Q R &&
+	ls R/objects/pack/*.pack >packs.txt &&
+	test_line_count = 1 packs.txt
+'
 
 test_done