From: Derrick Stolee Date: Mon, 20 Aug 2018 19:54:25 GMT Subject: Re: [PATCH v2 0/8] Clarify commit-graph and grafts/replace/shallow incompatibilities Message-ID: In-Reply-To: On 8/20/2018 3:37 PM, Stefan Beller wrote: > On Mon, Aug 20, 2018 at 11:24 AM Derrick Stolee wrote: >> One unresolved issue with the commit-graph feature is that it can cause >> issues when combined with replace objects, commit grafts, or shallow >> clones. These are not 100% incompatible, as one could be reasonably >> successful writing a commit-graph after replacing some objects and not >> have issues. The problems happen when commits that are already in the >> commit-graph file are replaced, or when git is run with the >> `--no-replace-objects` option; this can cause incorrect parents or >> incorrect generation numbers. Similar things occur with commit grafts >> and shallow clones, especially when running `git fetch --unshallow` in a >> shallow repo. >> >> Instead of trying (and probably failing) to make these features work >> together, default to making the commit-graph feature unavailable in these >> situations. Create a new method 'commit_graph_compatible(r)' that checks >> if the repository 'r' has any of these features enabled. >> >> CHANGES IN V2: >> >> * The first two commits regarding the ref iterators are unchanged, despite >> a lot of discussion on the subject [1]. >> >> * I included Peff's changes in jk/core-use-replace-refs, changing the base >> commit for the series to 1689c22c1c328e9135ed51458e9f9a5d224c5057 (the merge >> that brought that topic into 'msater'). >> >> * I fixed the tests for the interactions with the graft feature. >> >> Because of the change of base, it is hard to provide a side-by-side diff >> from v1. >> >> Thanks, >> -Stolee >> >> [1] https://public-inbox.org/git/CAGZ79kZ3PzqpGzXWcmxjzi98gA+LT2MBOf8KaA89hOa-Qig=Og@mail.gmail.com/ >> Stefan's response recommending we keep the first two commits. >> > After reviewing my own patches, I flipped again (Sorry!) and would > rather not see my patches be merged, but the very original solution > by you, that you proposed at [1]. That said, I will not insist on it, and > if this is merged as is, we can fix it up later. > > With that said, I just read through the remaining patches, I think > they are a valuable addition to Git and could be merged as-is. > > [1] https://github.com/gitgitgadget/git/pull/11/commits/300db80140dacc927db0d46c804ca0ef4dcc1be1 > > Thanks, > Stefan Just to keep things on-list as possible, here is the patch for the commit linked above. It would replace patches 1 & 2 from this series. Junio: I can send a v3 that includes this commit if you need it, or if there are other edits to be made in this series. commit 300db80140dacc927db0d46c804ca0ef4dcc1be1 Author: Derrick Stolee Date:   Fri Jul 20 15:39:06 2018 -0400     replace-objects: use arbitrary repositories     This is the smallest possible change that makes prepare_replace_objects     work properly with arbitrary repositories. By supplying the repository     as the cb_data, we do not need to modify any code in the ref iterator     logic. We will likely want to do a full replacement of the ref iterator     logic to provide a repository struct as a concrete parameter.     Signed-off-by: Derrick Stolee diff --git a/replace-object.c b/replace-object.c index 801b5c1678..e99fcd1ff6 100644 --- a/replace-object.c +++ b/replace-object.c @@ -14,6 +14,7 @@ static int register_replace_ref(const char *refname,         const char *slash = strrchr(refname, '/');         const char *hash = slash ? slash + 1 : refname;         struct replace_object *repl_obj = xmalloc(sizeof(*repl_obj)); +       struct repository *r = (struct repository *)cb_data;         if (get_oid_hex(hash, &repl_obj->original.oid)) {                 free(repl_obj); @@ -25,7 +26,7 @@ static int register_replace_ref(const char *refname,         oidcpy(&repl_obj->replacement, oid);         /* Register new object */ -       if (oidmap_put(the_repository->objects->replace_map, repl_obj)) +       if (oidmap_put(r->objects->replace_map, repl_obj))                 die("duplicate replace ref: %s", refname);         return 0; @@ -40,7 +41,7 @@ static void prepare_replace_object(struct repository *r)                 xmalloc(sizeof(*r->objects->replace_map));         oidmap_init(r->objects->replace_map, 0); -       for_each_replace_ref(r, register_replace_ref, NULL); +       for_each_replace_ref(r, register_replace_ref, r);  }  /* We allow "recursive" replacement. Only within reason, though */