[PATCH 10/27] sha1_file: add repository argument to link_alt_odb_entry

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

From: Stefan Beller <sbeller@google.com>

Add a repository argument to allow the link_alt_odb_entry caller to be
more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

Since the implementation does not yet work with other repositories,
use a wrapper macro to enforce that the caller passes in
the_repository as the first argument. It would be more appealing to
use BUILD_ASSERT_OR_ZERO to enforce this, but that doesn't work
because it requires a compile-time constant and common compilers like
gcc 4.8.4 do not consider "r == the_repository" a compile-time
constant.

This and the following three patches add repository arguments to
link_alt_odb_entry, read_info_alternates, link_alt_odb_entries
and prepare_alt_odb. Three out of the four functions are found
in a recursive call chain, calling each other, and one of them
accesses the repositories `objectdir` (which was migrated; it
was an obvious choice) and `ignore_env` (which we need to keep in
the repository struct for clarify); hence we will pass through the
repository unlike just the object store object + the ignore_env flag.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sha1_file.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/sha1_file.c b/sha1_file.c
index 097c372d03..7c0ace646a 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -391,8 +391,9 @@ static int alt_odb_usable(struct raw_object_store *o,
  * terminating NUL.
  */
 static void read_info_alternates(const char * relative_base, int depth);
-static int link_alt_odb_entry(const char *entry, const char *relative_base,
-	int depth, const char *normalized_objdir)
+#define link_alt_odb_entry(r, e, rb, d, n) link_alt_odb_entry_##r(e, rb, d, n)
+static int link_alt_odb_entry_the_repository(const char *entry,
+	const char *relative_base, int depth, const char *normalized_objdir)
 {
 	struct alternate_object_database *ent;
 	struct strbuf pathbuf = STRBUF_INIT;
@@ -489,7 +490,8 @@ static void link_alt_odb_entries(const char *alt, int sep,
 		alt = parse_alt_odb_entry(alt, sep, &entry);
 		if (!entry.len)
 			continue;
-		link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf);
+		link_alt_odb_entry(the_repository, entry.buf,
+				   relative_base, depth, objdirbuf.buf);
 	}
 	strbuf_release(&entry);
 	strbuf_release(&objdirbuf);
-- 
2.17.0.rc0.348.gd5a49e0b6f