Re: [PATCH] Fix "unpack-objects --strict"

> When unpack-objects is run under the --strict option, objects that have
> pointers to other objects are verified for the reachability at the end, by
> calling check_object() on each of them, and letting check_object to walk
> the reachable objects from them using fsck_walk() recursively.
> 
> The function however misunderstands the semantics of fsck_walk() function
> when it makes a call to it, setting itself as the callback.  fsck_walk()
> expects the callback function to return a non-zero value to signal an
> error (negative value causes an immediate abort, positive value is still
> an error but allows further checks on sibling objects) and return zero to
> signal a success.  The function however returned 1 on some non error
> cases, and to cover up this mistake, complained only when fsck_walk() did
> not detect any error.
> 
> To fix this double-bug, make the function return zero on all success
> cases, and also check for non-zero return from fsck_walk() for an error.