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, 4 insertions, 3 deletions

diff --git a/third_party/git/Documentation/config/branch.txt b/third_party/git/Documentation/config/branch.txt
index a592d522a744..cc5f3249fc58 100644
--- a/third_party/git/Documentation/config/branch.txt
+++ b/third_party/git/Documentation/config/branch.txt
@@ -81,15 +81,16 @@ branch.<name>.rebase::
 	"git pull" is run. See "pull.rebase" for doing this in a non
 	branch-specific manner.
 +
-When `merges`, pass the `--rebase-merges` option to 'git rebase'
+When `merges` (or just 'm'), pass the `--rebase-merges` option to 'git rebase'
 so that the local merge commits are included in the rebase (see
 linkgit:git-rebase[1] for details).
 +
-When `preserve` (deprecated in favor of `merges`), also pass
+When `preserve` (or just 'p', deprecated in favor of `merges`), also pass
 `--preserve-merges` along to 'git rebase' so that locally committed merge
 commits will not be flattened by running 'git pull'.
 +
-When the value is `interactive`, the rebase is run in interactive mode.
+When the value is `interactive` (or just 'i'), the rebase is run in interactive
+mode.
 +
 *NOTE*: this is a possibly dangerous operation; do *not* use
 it unless you understand the implications (see linkgit:git-rebase[1]