git/refs.c, branch v2.3.7

refs.c: drop curate_packed_refs

2015-03-20T19:41:41Z

When we delete a ref, we have to rewrite the entire packed-refs file. We take this opportunity to "curate" the packed-refs file and drop any entries that are crufty or broken. Dropping broken entries (e.g., with bogus names, or ones that point to missing objects) is actively a bad idea, as it means that we lose any notion that the data was there in the first place. Aside from the general hackiness that we might lose any information about ref "foo" while deleting an unrelated ref "bar", this may seriously hamper any attempts by the user at recovering from the corruption in "foo". They will lose the sha1 and name of "foo"; the exact pointer may still be useful even if they recover missing objects from a different copy of the repository. But worse, once the ref is gone, there is no trace of the corruption. A follow-up "git prune" may delete objects, even though it would otherwise bail when seeing corruption. We could just drop the "broken" bits from curate_packed_refs, and continue to drop the "crufty" bits: refs whose loose counterpart exists in the filesystem. This is not wrong to do, and it does have the advantage that we may write out a slightly smaller packed-refs file. But it has two disadvantages: 1. It is a potential source of races or mistakes with respect to these refs that are otherwise unrelated to the operation. To my knowledge, there aren't any active problems in this area, but it seems like an unnecessary risk. 2. We have to spend time looking up the matching loose refs for every item in the packed-refs file. If you have a large number of packed refs that do not change, that outweighs the benefit from writing out a smaller packed-refs file (it doesn't get smaller, and you do a bunch of directory traversal to find that out). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

refs: introduce a "ref paranoia" flag

2015-03-20T19:40:49Z

Most operations that iterate over refs are happy to ignore broken cruft. However, some operations should be performed with knowledge of these broken refs, because it is better for the operation to choke on a missing object than it is to silently pretend that the ref did not exist (e.g., if we are computing the set of reachable tips in order to prune objects). These processes could just call for_each_rawref, except that ref iteration is often hidden behind other interfaces. For instance, for a destructive "repack -ad", we would have to inform "pack-objects" that we are destructive, and then it would in turn have to tell the revision code that our "--all" should include broken refs. It's much simpler to just set a global for "dangerous" operations that includes broken refs in all iterations. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'jk/blame-commit-label' into maint

2015-02-25T06:09:54Z

"git blame HEAD -- missing" failed to correctly say "HEAD" when it tried to say "No such path 'missing' in HEAD". * jk/blame-commit-label: blame.c: fix garbled error message use xstrdup_or_null to replace ternary conditionals builtin/commit.c: use xstrdup_or_null instead of envdup builtin/apply.c: use xstrdup_or_null instead of null_strdup git-compat-util: add xstrdup_or_null helper

use xstrdup_or_null to replace ternary conditionals

2015-01-13T18:05:48Z

This replaces "x ? xstrdup(x) : NULL" with xstrdup_or_null(x). The change is fairly mechanical, with the exception of resolve_refdup, which can eliminate a temporary variable. There are still a few hits grepping for "?.*xstrdup", but these are of slightly different forms and cannot be converted (e.g., "x ? xstrdup(x->foo) : NULL"). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

refs: plug strbuf leak in lock_ref_sha1_basic()

2014-12-29T21:14:16Z

Don't just reset, but release the resource held by the local variable that is about to go out of scope. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano

Merge branch 'jk/read-packed-refs-without-path-max'

2014-12-22T20:28:04Z

Git did not correctly read an overlong refname from a packed refs file. * jk/read-packed-refs-without-path-max: read_packed_refs: use skip_prefix instead of static array read_packed_refs: pass strbuf to parse_ref_line read_packed_refs: use a strbuf for reading lines

Merge branch 'jk/for-each-reflog-ent-reverse'

2014-12-22T20:27:32Z

The code that reads the reflog from the newer to the older entries did not handle an entry that crosses a boundary of block it uses to read them correctly. * jk/for-each-reflog-ent-reverse: for_each_reflog_ent_reverse: turn leftover check into assertion for_each_reflog_ent_reverse: fix newlines on block boundaries

Merge branch 'mh/simplify-repack-without-refs'

2014-12-22T20:26:50Z

"git remote update --prune" to drop many refs has been optimized. * mh/simplify-repack-without-refs: sort_string_list(): rename to string_list_sort() prune_remote(): iterate using for_each_string_list_item() prune_remote(): rename local variable repack_without_refs(): make the refnames argument a string_list prune_remote(): sort delete_refs_list references en masse prune_remote(): initialize both delete_refs lists in a single loop prune_remote(): exit early if there are no stale references

read_packed_refs: use skip_prefix instead of static array

2014-12-10T17:40:33Z

We want to recognize the packed-refs header and skip to the "traits" part of the line. We currently do it by feeding sizeof() a static const array to strncmp. However, it's a bit simpler to just skip_prefix, which expresses the intention more directly, and without remembering to account for the NUL-terminator in each sizeof() call. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

read_packed_refs: pass strbuf to parse_ref_line

2014-12-10T17:28:54Z

Now that we have a strbuf in read_packed_refs, we can pass it straight to the line parser, which saves us an extra strlen. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano