From 7dd84a769ede910fb18178e3737e65df470f9e6c Mon Sep 17 00:00:00 2001
From: Ross Churchley <ross@rosschurchley.com>
Date: Thu, 16 Jul 2015 23:59:03 -0700
Subject: [PATCH] Fix `\plain` centering bug

Earlier versions of Beamer (or XeLaTeX?) did not respect `\centering` on the only line of a page. This is fixed by replacing `\centering` with the `center` environment, which breaks the paragraph before and after the line.
---
 beamerthemem.dtx | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/beamerthemem.dtx b/beamerthemem.dtx
index 9e6d9c4..543843f 100644
--- a/beamerthemem.dtx
+++ b/beamerthemem.dtx
@@ -187,10 +187,11 @@
       parent=palette primary
     }
     \begin{frame}[c]{#1}
-      \centering
-      \usebeamercolor[fg]{palette primary}
-      \usebeamerfont{section title}
-      \@metropolis@plaintitleformat{#2}
+      \begin{center}
+        \usebeamercolor[fg]{palette primary}
+        \usebeamerfont{section title}
+        \@metropolis@plaintitleformat{#2}
+      \end{center}
     \end{frame}
   \endgroup
 }