From c71244ca37022167536cd9bd6c6f8104da92cf52 Mon Sep 17 00:00:00 2001
From: Antony Lee <anntzer.lee@gmail.com>
Date: Mon, 30 Sep 2019 16:13:58 +0200
Subject: [PATCH] Don't generate double-reversed cmaps ("viridis_r_r", ...).

_gen_cmap_d handles reversal of all colormaps, so _cm_listed doesn't
need to generate reversed colormaps anymore -- otherwise, one gets the
"double-reversed" colormaps `viridis_r_r`, etc.
---
 lib/matplotlib/_cm_listed.py | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/lib/matplotlib/_cm_listed.py b/lib/matplotlib/_cm_listed.py
index cd70b28197b0..e7ca0ef6c7e6 100644
--- a/lib/matplotlib/_cm_listed.py
+++ b/lib/matplotlib/_cm_listed.py
@@ -1801,16 +1801,13 @@
                           _twilight_data[:len(_twilight_data)//2])
 _twilight_shifted_data.reverse()
 
-cmaps = {}
-for (name, data) in (('magma', _magma_data),
-                     ('inferno', _inferno_data),
-                     ('plasma', _plasma_data),
-                     ('viridis', _viridis_data),
-                     ('cividis', _cividis_data),
-                     ('twilight', _twilight_data),
-                     ('twilight_shifted', _twilight_shifted_data)):
-
-    cmaps[name] = ListedColormap(data, name=name)
-    # generate reversed colormap
-    name = name + '_r'
-    cmaps[name] = ListedColormap(list(reversed(data)), name=name)
+cmaps = {
+    name: ListedColormap(data, name=name) for name, data in [
+        ('magma', _magma_data),
+        ('inferno', _inferno_data),
+        ('plasma', _plasma_data),
+        ('viridis', _viridis_data),
+        ('cividis', _cividis_data),
+        ('twilight', _twilight_data),
+        ('twilight_shifted', _twilight_shifted_data),
+    ]}