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, 44 insertions, 17 deletions

diff --git a/third_party/git/worktree.h b/third_party/git/worktree.h
index caecc7a281..f38e6fd5a2 100644
--- a/third_party/git/worktree.h
+++ b/third_party/git/worktree.h
@@ -18,19 +18,14 @@ struct worktree {
 	int lock_reason_valid; /* private */
 };
 
-/* Functions for acting on the information about worktrees. */
-
-#define GWT_SORT_LINKED (1 << 0) /* keeps linked worktrees sorted */
-
 /*
  * Get the worktrees.  The primary worktree will always be the first returned,
- * and linked worktrees will be pointed to by 'next' in each subsequent
- * worktree.  No specific ordering is done on the linked worktrees.
+ * and linked worktrees will follow in no particular order.
  *
  * The caller is responsible for freeing the memory from the returned
- * worktree(s).
+ * worktrees by calling free_worktrees().
  */
-struct worktree **get_worktrees(unsigned flags);
+struct worktree **get_worktrees(void);
 
 /*
  * Returns 1 if linked worktrees exist, 0 otherwise.
@@ -44,14 +39,30 @@ int submodule_uses_worktrees(const char *path);
 const char *get_worktree_git_dir(const struct worktree *wt);
 
 /*
- * Search a worktree that can be unambiguously identified by
- * "arg". "prefix" must not be NULL.
+ * Search for the worktree identified unambiguously by `arg` -- typically
+ * supplied by the user via the command-line -- which may be a pathname or some
+ * shorthand uniquely identifying a worktree, thus making it convenient for the
+ * user to specify a worktree with minimal typing. For instance, if the last
+ * component (say, "foo") of a worktree's pathname is unique among worktrees
+ * (say, "work/foo" and "work/bar"), it can be used to identify the worktree
+ * unambiguously.
+ *
+ * `prefix` should be the `prefix` handed to top-level Git commands along with
+ * `argc` and `argv`.
+ *
+ * Return the worktree identified by `arg`, or NULL if not found.
  */
 struct worktree *find_worktree(struct worktree **list,
 			       const char *prefix,
 			       const char *arg);
 
 /*
+ * Return the worktree corresponding to `path`, or NULL if no such worktree
+ * exists.
+ */
+struct worktree *find_worktree_by_path(struct worktree **, const char *path);
+
+/*
  * Return true if the given worktree is the main one.
  */
 int is_main_worktree(const struct worktree *wt);
@@ -78,6 +89,29 @@ int validate_worktree(const struct worktree *wt,
 void update_worktree_location(struct worktree *wt,
 			      const char *path_);
 
+typedef void (* worktree_repair_fn)(int iserr, const char *path,
+				    const char *msg, void *cb_data);
+
+/*
+ * Visit each registered linked worktree and repair corruptions. For each
+ * repair made or error encountered while attempting a repair, the callback
+ * function, if non-NULL, is called with the path of the worktree and a
+ * description of the repair or error, along with the callback user-data.
+ */
+void repair_worktrees(worktree_repair_fn, void *cb_data);
+
+/*
+ * Repair administrative files corresponding to the worktree at the given path.
+ * The worktree's .git file pointing at the repository must be intact for the
+ * repair to succeed. Useful for re-associating an orphaned worktree with the
+ * repository if the worktree has been moved manually (without using "git
+ * worktree move"). For each repair made or error encountered while attempting
+ * a repair, the callback function, if non-NULL, is called with the path of the
+ * worktree and a description of the repair or error, along with the callback
+ * user-data.
+ */
+void repair_worktree_at_path(const char *, worktree_repair_fn, void *cb_data);
+
 /*
  * Free up the memory for worktree(s)
  */
@@ -125,11 +159,4 @@ void strbuf_worktree_ref(const struct worktree *wt,
 			 struct strbuf *sb,
 			 const char *refname);
 
-/*
- * Return a refname suitable for access from the current ref
- * store. The result will be destroyed at the next call.
- */
-const char *worktree_ref(const struct worktree *wt,
-			 const char *refname);
-
 #endif