Merge branch 'maint'

* maint:
  git-prompt: Document GIT_PS1_DESCRIBE_STYLE

Author: gitster

contrib/completion/git-prompt.sh

@@ -55,10 +55,19 @@
 # GIT_PS1_SHOWUPSTREAM, you can override it on a per-repository basis by
 # setting the bash.showUpstream config variable.
 #
+# If you would like to see more information about the identity of
+# commits checked out as a detached HEAD, set GIT_PS1_DESCRIBE_STYLE
+# to one of these values:
+#
+#     contains      relative to newer annotated tag (v1.6.3.2~35)
+#     branch        relative to newer tag or branch (master~4)
+#     describe      relative to older annotated tag (v1.6.3.1-13-gdd42c2f)
+#     default       exactly matching tag
+#
 # If you would like a colored hint about the current dirty state, set
 # GIT_PS1_SHOWCOLORHINTS to a nonempty value. The colors are based on
 # the colored output of "git status -sb".
-#
+
 # __gitdir accepts 0 or 1 arguments (i.e., location)
 # returns location of .git repo
 __gitdir ()