Re: fact-import: failed to apply delta

["Shawn O. Pearce" <spearce@spearce.org>]

Daniel Barkalow <barkalow@iabervon.org> wrote:
> 
> I think free_pack_by_name() also needs to drop the entries that are from 
> the freed pack, to avoid having repack able to get the same problem, 
> although I wouldn't be surprised if repack happened to never allocate a 
> new pack after freeing an old pack with stale delta cache entries, or 
> never used the delta cache after that, simply because it does one thing 
> and then exits.

Oy.  I missed that we added this function.  Patch follows.

--8<--
Clear the delta base cache if a pack is rebuilt

There is some risk that re-opening a regenerated pack file with
different offsets could leave stale entries within the delta base
cache that could be matched up against other objects using the same
"struct packed_git*" and pack offset.

Throwing away the entire delta base cache in this case is safer,
as we don't have to worry about a recycled "struct packed_git*"
matching to the wrong base object, resulting in delta apply
errors while unpacking an object.

Suggested-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 sha1_file.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/sha1_file.c b/sha1_file.c
index 7459a9c..5b6e0f6 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -689,6 +689,7 @@ void free_pack_by_name(const char *pack_name)
 	while (*pp) {
 		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);
-- 
1.6.2.rc0.186.g417c