From 5be3c6df52e412b6b0c937c997ab770a3a9cd27c Mon Sep 17 00:00:00 2001
From: Antony Lee <anntzer.lee@gmail.com>
Date: Wed, 28 Mar 2018 14:40:37 -0700
Subject: [PATCH] Rely a bit more on rc_context.

---
 lib/matplotlib/style/core.py             |  9 ++---
 lib/matplotlib/tests/test_backend_pgf.py | 42 +++++++++++-------------
 2 files changed, 22 insertions(+), 29 deletions(-)

diff --git a/lib/matplotlib/style/core.py b/lib/matplotlib/style/core.py
index 2a836721882b..650f80e6cb47 100644
--- a/lib/matplotlib/style/core.py
+++ b/lib/matplotlib/style/core.py
@@ -136,14 +136,11 @@ def context(style, after_reset=False):
         If True, apply style after resetting settings to their defaults;
         otherwise, apply style on top of the current settings.
     """
-    initial_settings = mpl.rcParams.copy()
-    if after_reset:
-        mpl.rcdefaults()
-    try:
+    with mpl.rc_context():
+        if after_reset:
+            mpl.rcdefaults()
         use(style)
         yield
-    finally:
-        mpl.rcParams.update(initial_settings)
 
 
 def load_base_library():
diff --git a/lib/matplotlib/tests/test_backend_pgf.py b/lib/matplotlib/tests/test_backend_pgf.py
index 1a3d943cf3da..1bc49b056eed 100644
--- a/lib/matplotlib/tests/test_backend_pgf.py
+++ b/lib/matplotlib/tests/test_backend_pgf.py
@@ -117,30 +117,26 @@ def test_pdflatex():
 @pytest.mark.style('default')
 @pytest.mark.backend('pgf')
 def test_rcupdate():
-    rc_sets = []
-    rc_sets.append({'font.family': 'sans-serif',
-                    'font.size': 30,
-                    'figure.subplot.left': .2,
-                    'lines.markersize': 10,
-                    'pgf.rcfonts': False,
-                    'pgf.texsystem': 'xelatex'})
-    rc_sets.append({'font.family': 'monospace',
-                    'font.size': 10,
-                    'figure.subplot.left': .1,
-                    'lines.markersize': 20,
-                    'pgf.rcfonts': False,
-                    'pgf.texsystem': 'pdflatex',
-                    'pgf.preamble': ['\\usepackage[utf8x]{inputenc}',
-                                     '\\usepackage[T1]{fontenc}',
-                                     '\\usepackage{sfmath}']})
-    tol = (6, 0)
-    original_params = mpl.rcParams.copy()
+    rc_sets = [{'font.family': 'sans-serif',
+                'font.size': 30,
+                'figure.subplot.left': .2,
+                'lines.markersize': 10,
+                'pgf.rcfonts': False,
+                'pgf.texsystem': 'xelatex'},
+               {'font.family': 'monospace',
+                'font.size': 10,
+                'figure.subplot.left': .1,
+                'lines.markersize': 20,
+                'pgf.rcfonts': False,
+                'pgf.texsystem': 'pdflatex',
+                'pgf.preamble': ['\\usepackage[utf8x]{inputenc}',
+                                 '\\usepackage[T1]{fontenc}',
+                                 '\\usepackage{sfmath}']}]
+    tol = [6, 0]
     for i, rc_set in enumerate(rc_sets):
-        mpl.rcParams.clear()
-        mpl.rcParams.update(original_params)
-        mpl.rcParams.update(rc_set)
-        create_figure()
-        compare_figure('pgf_rcupdate%d.pdf' % (i + 1), tol=tol[i])
+        with mpl.rc_context(rc_set):
+            create_figure()
+            compare_figure('pgf_rcupdate%d.pdf' % (i + 1), tol=tol[i])
 
 
 # test backend-side clipping, since large numbers are not supported by TeX