Merge branch 'mh/doc-windows-home-env'

Doc update.

* mh/doc-windows-home-env:
  Document HOME environment variable

Author: gitster

Documentation/git.txt

@@ -477,6 +477,14 @@ their values the same way as Boolean valued configuration variables, e.g.
 
 Here are the variables:
 
+System
+~~~~~~~~~~~~~~~~~~
+`HOME`::
+	Specifies the path to the user's home directory. On Windows, if
+	unset, Git will set a process environment variable equal to:
+	`$HOMEDRIVE$HOMEPATH` if both `$HOMEDRIVE` and `$HOMEPATH` exist;
+	otherwise `$USERPROFILE` if `$USERPROFILE` exists.
+
 The Git Repository
 ~~~~~~~~~~~~~~~~~~
 These environment variables apply to 'all' core Git commands. Nb: it