Add patch to fix Qt4 backends.

12157.patch

@@ -0,0 +1,31 @@
+From bb337935d04b63d454a81e16a9ac2063a7d945c3 Mon Sep 17 00:00:00 2001
+From: Antony Lee <anntzer.lee@gmail.com>
+Date: Tue, 18 Sep 2018 22:46:17 +0200
+Subject: [PATCH] Properly declare the interactive framework for the qt4foo
+ backends.
+
+---
+ lib/matplotlib/backends/backend_qt4agg.py   | 2 +-
+ lib/matplotlib/backends/backend_qt4cairo.py | 2 +-
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/lib/matplotlib/backends/backend_qt4agg.py b/lib/matplotlib/backends/backend_qt4agg.py
+index 65785bbd32b..8f4e265ac42 100644
+--- a/lib/matplotlib/backends/backend_qt4agg.py
++++ b/lib/matplotlib/backends/backend_qt4agg.py
+@@ -8,4 +8,4 @@
+ 
+ @_BackendQT5Agg.export
+ class _BackendQT4Agg(_BackendQT5Agg):
+-    pass
++    required_interactive_framework = "qt4"
+diff --git a/lib/matplotlib/backends/backend_qt4cairo.py b/lib/matplotlib/backends/backend_qt4cairo.py
+index f94851da382..94d703afa4e 100644
+--- a/lib/matplotlib/backends/backend_qt4cairo.py
++++ b/lib/matplotlib/backends/backend_qt4cairo.py
+@@ -3,4 +3,4 @@
+ 
+ @_BackendQT5Cairo.export
+ class _BackendQT4Cairo(_BackendQT5Cairo):
+-    pass
++    required_interactive_framework = "qt4"

python-matplotlib.spec

@@ -52,6 +52,8 @@ Source1:        setup.cfg
 # Because the qhull package stopped shipping pkgconfig files.
 # https://src.fedoraproject.org/rpms/qhull/pull-request/1
 Patch0001:      0001-Force-using-system-qhull.patch
+# https://github.com/matplotlib/matplotlib/pull/12157
+Patch0002:      12157.patch
 
 # Fedora-specific patches; see:
 # https://github.com/QuLogic/matplotlib/tree/fedora-patches
@@ -240,6 +242,7 @@ Requires:       python3-matplotlib%{?_isa} = %{version}-%{release}
 %prep
 %autosetup -n matplotlib-%{version}%{?rctag} -N
 %patch0001 -p1
+%patch0002 -p1
 
 # Fedora-specific patches follow:
 %patch1001 -p1