From ee4dfee2274d2fd743066fa9fa4d37441ee522f8 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Tue, 9 Apr 2019 19:13:23 -0700 Subject: rev-list: let traversal die when --missing is not in use Commit 7c0fe330d5 (rev-list: handle missing tree objects properly, 2018-10-05) taught the traversal machinery used by git-rev-list to ignore missing trees, so that rev-list could handle them itself. However, it does so only by checking via oid_object_info_extended() that the object exists at all. This can miss several classes of errors that were previously detected by rev-list: - type mismatches (e.g., we expected a tree but got a blob) - failure to read the object data (e.g., due to bitrot on disk) This is especially important because we use "rev-list --objects" as our connectivity check to admit new objects to the repository, and it will now miss these cases (though the bitrot one is less important here, because we'd typically have just hashed and stored the object). There are a few options to fix this: 1. we could check these properties in rev-list when we do the existence check. This is probably too expensive in practice (perhaps even for a type check, but definitely for checking the whole content again, which implies loading each object into memory twice). 2. teach the traversal machinery to differentiate between a missing object, and one that could not be loaded as expected. This probably wouldn't be too hard to detect type mismatches, but detecting bitrot versus a truly missing object would require deep changes to the object-loading code. 3. have the traversal machinery communicate the failure to the caller, so that it can decide how to proceed without re-evaluting the object itself. Of those, I think (3) is probably the best path forward. However, this patch does none of them. In the name of expediently fixing the regression to a normal "rev-list --objects" that we use for connectivity checks, this simply restores the pre-7c0fe330d5 behavior of having the traversal die as soon as it fails to load a tree (when --missing is set to MA_ERROR, which is the default). Note that we can't get rid of the object-existence check in finish_object(), because this also handles blobs (which are not otherwise checked at all by the traversal code). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- builtin/rev-list.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'builtin/rev-list.c') diff --git a/builtin/rev-list.c b/builtin/rev-list.c index 5b5b6dbb1c..7de083b5f6 100644 --- a/builtin/rev-list.c +++ b/builtin/rev-list.c @@ -379,7 +379,6 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix) repo_init_revisions(the_repository, &revs, prefix); revs.abbrev = DEFAULT_ABBREV; revs.commit_format = CMIT_FMT_UNSPECIFIED; - revs.do_not_die_on_missing_tree = 1; /* * Scan the argument list before invoking setup_revisions(), so that we @@ -409,6 +408,9 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix) } } + if (arg_missing_action) + revs.do_not_die_on_missing_tree = 1; + argc = setup_revisions(argc, argv, &revs, &s_r_opt); memset(&info, 0, sizeof(info)); -- cgit v1.2.3