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, 37 insertions, 18 deletions

diff --git a/third_party/git/Documentation/git-checkout.txt b/third_party/git/Documentation/git-checkout.txt
index cf3cac0a2b51..afa5c11fd3c4 100644
--- a/third_party/git/Documentation/git-checkout.txt
+++ b/third_party/git/Documentation/git-checkout.txt
@@ -12,14 +12,14 @@ SYNOPSIS
 'git checkout' [-q] [-f] [-m] --detach [<branch>]
 'git checkout' [-q] [-f] [-m] [--detach] <commit>
 'git checkout' [-q] [-f] [-m] [[-b|-B|--orphan] <new_branch>] [<start_point>]
-'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>...
-'git checkout' [<tree-ish>] [--] <pathspec>...
-'git checkout' (-p|--patch) [<tree-ish>] [--] [<paths>...]
+'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <pathspec>...
+'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] --pathspec-from-file=<file> [--pathspec-file-nul]
+'git checkout' (-p|--patch) [<tree-ish>] [--] [<pathspec>...]
 
 DESCRIPTION
 -----------
 Updates files in the working tree to match the version in the index
-or the specified tree.  If no paths are given, 'git checkout' will
+or the specified tree.  If no pathspec was given, 'git checkout' will
 also update `HEAD` to set the specified branch as the current
 branch.
 
@@ -79,13 +79,14 @@ be used to detach `HEAD` at the tip of the branch (`git checkout
 +
 Omitting `<branch>` detaches `HEAD` at the tip of the current branch.
 
-'git checkout' [<tree-ish>] [--] <pathspec>...::
+'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <pathspec>...::
+'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] --pathspec-from-file=<file> [--pathspec-file-nul]::
 
-	Overwrite paths in the working tree by replacing with the
-	contents in the index or in the `<tree-ish>` (most often a
-	commit).  When a `<tree-ish>` is given, the paths that
-	match the `<pathspec>` are updated both in the index and in
-	the working tree.
+	Overwrite the contents of the files that match the pathspec.
+	When the `<tree-ish>` (most often a commit) is not given,
+	overwrite working tree with the contents in the index.
+	When the `<tree-ish>` is given, overwrite both the index and
+	the working tree with the contents at the `<tree-ish>`.
 +
 The index may contain unmerged entries because of a previous failed merge.
 By default, if you try to check out such an entry from the index, the
@@ -96,12 +97,10 @@ using `--ours` or `--theirs`.  With `-m`, changes made to the working tree
 file can be discarded to re-create the original conflicted merge result.
 
 'git checkout' (-p|--patch) [<tree-ish>] [--] [<pathspec>...]::
-	This is similar to the "check out paths to the working tree
-	from either the index or from a tree-ish" mode described
-	above, but lets you use the interactive interface to show
-	the "diff" output and choose which hunks to use in the
-	result.  See below for the description of `--patch` option.
-
+	This is similar to the previous mode, but lets you use the
+	interactive interface to show the "diff" output and choose which
+	hunks to use in the result.  See below for the description of
+	`--patch` option.
 
 OPTIONS
 -------
@@ -199,6 +198,7 @@ Use `--no-guess` to disable this.
 	Create the new branch's reflog; see linkgit:git-branch[1] for
 	details.
 
+-d::
 --detach::
 	Rather than checking out a branch to work on it, check out a
 	commit for inspection and discardable experiments.
@@ -293,11 +293,11 @@ Note that this option uses the no overlay mode by default (see also
 
 --recurse-submodules::
 --no-recurse-submodules::
-	Using `--recurse-submodules` will update the content of all initialized
+	Using `--recurse-submodules` will update the content of all active
 	submodules according to the commit recorded in the superproject. If
 	local modifications in a submodule would be overwritten the checkout
 	will fail unless `-f` is used. If nothing (or `--no-recurse-submodules`)
-	is used, the work trees of submodules will not be updated.
+	is used, submodules working trees will not be updated.
 	Just like linkgit:git-submodule[1], this will detach `HEAD` of the
 	submodule.
 
@@ -309,6 +309,19 @@ Note that this option uses the no overlay mode by default (see also
 	working tree, but not in `<tree-ish>` are removed, to make them
 	match `<tree-ish>` exactly.
 
+--pathspec-from-file=<file>::
+	Pathspec is passed in `<file>` instead of commandline args. If
+	`<file>` is exactly `-` then standard input is used. Pathspec
+	elements are separated by LF or CR/LF. Pathspec elements can be
+	quoted as explained for the configuration variable `core.quotePath`
+	(see linkgit:git-config[1]). See also `--pathspec-file-nul` and
+	global `--literal-pathspecs`.
+
+--pathspec-file-nul::
+	Only meaningful with `--pathspec-from-file`. Pathspec elements are
+	separated with NUL character and all other characters are taken
+	literally (including newlines and quotes).
+
 <branch>::
 	Branch to checkout; if it refers to a branch (i.e., a name that,
 	when prepended with "refs/heads/", is a valid ref), then that
@@ -339,7 +352,13 @@ leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
 	Tree to checkout from (when paths are given). If not specified,
 	the index will be used.
 
+\--::
+	Do not interpret any more arguments as options.
 
+<pathspec>...::
+	Limits the paths affected by the operation.
++
+For more details, see the 'pathspec' entry in linkgit:gitglossary[7].
 
 DETACHED HEAD
 -------------