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, 18 insertions, 0 deletions

diff --git a/third_party/git/Documentation/RelNotes/2.20.2.txt b/third_party/git/Documentation/RelNotes/2.20.2.txt
new file mode 100644
index 000000000000..8e680cb9fbf4
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.20.2.txt
@@ -0,0 +1,18 @@
+Git v2.20.2 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.14.6, v2.15.4
+and in v2.17.3, addressing the security issues CVE-2019-1348,
+CVE-2019-1349, CVE-2019-1350, CVE-2019-1351, CVE-2019-1352,
+CVE-2019-1353, CVE-2019-1354, and CVE-2019-1387; see the release notes
+for those versions for details.
+
+The change to disallow `submodule.<name>.update=!command` entries in
+`.gitmodules` which was introduced v2.15.4 (and for which v2.17.3
+added explicit fsck checks) fixes the vulnerability in v2.20.x where a
+recursive clone followed by a submodule update could execute code
+contained within the repository without the user explicitly having
+asked for that (CVE-2019-19604).
+
+Credit for finding this vulnerability goes to Joern Schneeweisz,
+credit for the fixes goes to Jonathan Nieder.