Subject: Re: Repository data loss in fast-export with a merge of a deleted submodule

From: Joshua Jensen <[email-masked]>
Date: Thu, 03 Nov 2011 10:05:09 -0600

----- Original Message -----
From: Joshua Jensen
Date: 10/27/2011 1:27 PM
> We had a submodule that we deleted and then added back into the 
> repository at the same location as the former submodule.  When running 
> fast-export, the newly 'added' files for the merge commit are listed 
> and then are followed with a:
>
> M ... path/to/submodule/file
> D path/to/submodule
>
> On fast-import, the resultant repository becomes corrupt due to the 
> Delete instruction above occurring AFTER the file adds/modifications.  
> The new repository does not match the old repository where the 
> fast-export was performed.
>
> I am not familiar with the fast-export code.  Can anyone help out?
Okay, I looked into this further, and I came up with a patch that works 
for me.  Nevertheless, I do not understand exactly what is going on 
here, so I would like to defer to someone else's patch to fix the issue.

-Josh

---
builtin/fast-export.c |    8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index 9836e6b..1abc470 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -161,6 +161,14 @@ static int depth_first(const void *a_, const void *b_)
                name_a = a->one ? a->one->path : a->two->path;
                name_b = b->one ? b->one->path : b->two->path;
+             /*
+             * Move 'D'elete entries first.
+             */
+             if (a->status == 'D')
+                             return -1;
+             else if (b->status == 'D')
+                             return 1;
+
                len_a = strlen(name_a);
                len_b = strlen(name_b);
                len = (len_a < len_b) ? len_a : len_b;
--