From 16ce2e4c8f9664f8ec5ae2bffed34d093d83a4d3 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Sat, 16 Aug 2008 23:02:08 -0700 Subject: [PATCH] index: future proof for "extended" index entries We do not have any more bits in the on-disk index flags word, but we would need to have more in the future. Use the last remaining bits as a signal to tell us that the index entry we are looking at is an extended one. Since we do not understand the extended format yet, we will just error out when we see it. Signed-off-by: Junio C Hamano --- cache.h | 1 + read-cache.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/cache.h b/cache.h index 2475de9fa8..7b5cc834ab 100644 --- a/cache.h +++ b/cache.h @@ -126,6 +126,7 @@ struct cache_entry { #define CE_NAMEMASK (0x0fff) #define CE_STAGEMASK (0x3000) +#define CE_EXTENDED (0x4000) #define CE_VALID (0x8000) #define CE_STAGESHIFT 12 diff --git a/read-cache.c b/read-cache.c index 2c03ec3069..f0ba224798 100644 --- a/read-cache.c +++ b/read-cache.c @@ -1118,6 +1118,10 @@ static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_en ce->ce_size = ntohl(ondisk->size); /* On-disk flags are just 16 bits */ ce->ce_flags = ntohs(ondisk->flags); + + /* For future extension: we do not understand this entry yet */ + if (ce->ce_flags & CE_EXTENDED) + die("Unknown index entry format"); hashcpy(ce->sha1, ondisk->sha1); len = ce->ce_flags & CE_NAMEMASK;