merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 38 insertions, 11 deletions

diff --git a/third_party/git/refs/refs-internal.h b/third_party/git/refs/refs-internal.h
index f2d8c0123a77..467f4b3c936d 100644
--- a/third_party/git/refs/refs-internal.h
+++ b/third_party/git/refs/refs-internal.h
@@ -32,6 +32,13 @@ struct ref_transaction;
 #define REF_HAVE_OLD (1 << 3)
 
 /*
+ * Used as a flag in ref_update::flags when we want to log a ref
+ * update but not actually perform it.  This is used when a symbolic
+ * ref update is split up.
+ */
+#define REF_LOG_ONLY (1 << 7)
+
+/*
  * Return the length of time to retry acquiring a loose reference lock
  * before giving up, in milliseconds:
  */
@@ -96,12 +103,6 @@ enum peel_status {
  */
 enum peel_status peel_object(const struct object_id *name, struct object_id *oid);
 
-/*
- * Copy the reflog message msg to sb while cleaning up the whitespaces.
- * Especially, convert LF to space, because reflog file is one line per entry.
- */
-void copy_reflog_msg(struct strbuf *sb, const char *msg);
-
 /**
  * Information needed for a single ref update. Set new_oid to the new
  * value or to null_oid to delete the ref. To check the old value
@@ -262,7 +263,7 @@ int refs_rename_ref_available(struct ref_store *refs,
  * after calling ref_iterator_advance() again or calling
  * ref_iterator_abort(), you must make a copy. When the iteration has
  * been exhausted, ref_iterator_advance() releases any resources
- * assocated with the iteration, frees the ref_iterator object, and
+ * associated with the iteration, frees the ref_iterator object, and
  * returns ITER_DONE. If you want to abort the iteration early, call
  * ref_iterator_abort(), which also frees the ref_iterator object and
  * any associated resources. If there was an internal error advancing
@@ -347,9 +348,13 @@ int is_empty_ref_iterator(struct ref_iterator *ref_iterator);
 /*
  * Return an iterator that goes over each reference in `refs` for
  * which the refname begins with prefix. If trim is non-zero, then
- * trim that many characters off the beginning of each refname. flags
- * can be DO_FOR_EACH_INCLUDE_BROKEN to include broken references in
- * the iteration. The output is ordered by refname.
+ * trim that many characters off the beginning of each refname.
+ * The output is ordered by refname. The following flags are supported:
+ *
+ * DO_FOR_EACH_INCLUDE_BROKEN: include broken references in
+ *         the iteration.
+ *
+ * DO_FOR_EACH_PER_WORKTREE_ONLY: only produce REF_TYPE_PER_WORKTREE refs.
  */
 struct ref_iterator *refs_ref_iterator_begin(
 		struct ref_store *refs,
@@ -438,6 +443,14 @@ void base_ref_iterator_free(struct ref_iterator *iter);
 
 /* Virtual function declarations for ref_iterators: */
 
+/*
+ * backend-specific implementation of ref_iterator_advance. For symrefs, the
+ * function should set REF_ISSYMREF, and it should also dereference the symref
+ * to provide the OID referent. If DO_FOR_EACH_INCLUDE_BROKEN is set, symrefs
+ * with non-existent referents and refs pointing to non-existent object names
+ * should also be returned. If DO_FOR_EACH_PER_WORKTREE_ONLY, only
+ * REF_TYPE_PER_WORKTREE refs should be returned.
+ */
 typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
 
 typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
@@ -661,18 +674,32 @@ extern struct ref_storage_be refs_be_packed;
 /*
  * A representation of the reference store for the main repository or
  * a submodule. The ref_store instances for submodules are kept in a
- * linked list.
+ * hash map; see get_submodule_ref_store() for more info.
  */
 struct ref_store {
 	/* The backend describing this ref_store's storage scheme: */
 	const struct ref_storage_be *be;
+
+	/* The gitdir that this ref_store applies to: */
+	char *gitdir;
 };
 
 /*
+ * Parse contents of a loose ref file.
+ */
+int parse_loose_ref_contents(const char *buf, struct object_id *oid,
+			     struct strbuf *referent, unsigned int *type);
+
+/*
  * Fill in the generic part of refs and add it to our collection of
  * reference stores.
  */
 void base_ref_store_init(struct ref_store *refs,
 			 const struct ref_storage_be *be);
 
+/*
+ * Support GIT_TRACE_REFS by optionally wrapping the given ref_store instance.
+ */
+struct ref_store *maybe_debug_wrap_ref_store(const char *gitdir, struct ref_store *store);
+
 #endif /* REFS_REFS_INTERNAL_H */