Sync with Git 2.20.1

* maint:
  Git 2.20.1
  .gitattributes: ensure t/oid-info/* has eol=lf
  t9902: 'send-email' test case requires PERL
  t4256: mark support files as LF-only
  parse-options: fix SunCC compiler warning
  help -a: handle aliases with long names gracefully
  help.h: fix coding style
  run-command: report exec failure
diff --git a/Documentation/RelNotes/2.21.0.txt b/Documentation/RelNotes/2.21.0.txt
new file mode 100644
index 0000000..ad681bd
--- /dev/null
+++ b/Documentation/RelNotes/2.21.0.txt
@@ -0,0 +1,22 @@
+Git 2.21 Release Notes
+======================
+
+Backward Compatibility Notes
+----------------------------
+
+
+Updates since v2.20
+-------------------
+
+UI, Workflows & Features
+
+
+
+Performance, Internal Implementation, Development Support etc.
+
+
+
+Fixes since v2.20
+-----------------
+
+ * Code cleanup, docfix, build fix, etc.
diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index d1a2814..0a3ccac 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 GVF=GIT-VERSION-FILE
-DEF_VER=v2.20.1
+DEF_VER=v2.20.GIT
 
 LF='
 '
diff --git a/RelNotes b/RelNotes
index 463a237..31e2135 120000
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/2.20.1.txt
\ No newline at end of file
+Documentation/RelNotes/2.21.0.txt
\ No newline at end of file