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, 0 insertions, 78 deletions

diff --git a/third_party/git/Documentation/technical/api-ref-iteration.txt b/third_party/git/Documentation/technical/api-ref-iteration.txt
deleted file mode 100644
index ad9d019ff9b4..000000000000
--- a/third_party/git/Documentation/technical/api-ref-iteration.txt
+++ /dev/null
@@ -1,78 +0,0 @@
-ref iteration API
-=================
-
-
-Iteration of refs is done by using an iterate function which will call a
-callback function for every ref. The callback function has this
-signature:
-
-	int handle_one_ref(const char *refname, const struct object_id *oid,
-			   int flags, void *cb_data);
-
-There are different kinds of iterate functions which all take a
-callback of this type. The callback is then called for each found ref
-until the callback returns nonzero. The returned value is then also
-returned by the iterate function.
-
-Iteration functions
--------------------
-
-* `head_ref()` just iterates the head ref.
-
-* `for_each_ref()` iterates all refs.
-
-* `for_each_ref_in()` iterates all refs which have a defined prefix and
-  strips that prefix from the passed variable refname.
-
-* `for_each_tag_ref()`, `for_each_branch_ref()`, `for_each_remote_ref()`,
-  `for_each_replace_ref()` iterate refs from the respective area.
-
-* `for_each_glob_ref()` iterates all refs that match the specified glob
-  pattern.
-
-* `for_each_glob_ref_in()` the previous and `for_each_ref_in()` combined.
-
-* Use `refs_` API for accessing submodules. The submodule ref store could
-  be obtained with `get_submodule_ref_store()`.
-
-* `for_each_rawref()` can be used to learn about broken ref and symref.
-
-* `for_each_reflog()` iterates each reflog file.
-
-Submodules
-----------
-
-If you want to iterate the refs of a submodule you first need to add the
-submodules object database. You can do this by a code-snippet like
-this:
-
-	const char *path = "path/to/submodule"
-	if (add_submodule_odb(path))
-		die("Error submodule '%s' not populated.", path);
-
-`add_submodule_odb()` will return zero on success. If you
-do not do this you will get an error for each ref that it does not point
-to a valid object.
-
-Note: As a side-effect of this you cannot safely assume that all
-objects you lookup are available in superproject. All submodule objects
-will be available the same way as the superprojects objects.
-
-Example:
---------
-
-----
-static int handle_remote_ref(const char *refname,
-		const unsigned char *sha1, int flags, void *cb_data)
-{
-	struct strbuf *output = cb_data;
-	strbuf_addf(output, "%s\n", refname);
-	return 0;
-}
-
-...
-
-	struct strbuf output = STRBUF_INIT;
-	for_each_remote_ref(handle_remote_ref, &output);
-	printf("%s", output.buf);
-----