Don't update style-blacklisted rcparams in rc_* functions.

anntzer · anntzer · commit 30d764b6f444 · 2018-07-12T15:59:01.000+02:00
This avoids incorrectly updating e.g. the ``backend`` or ``interactive``
rcParams.
diff --git a/doc/api/api_changes/2017-09-02-AL-rc-blacklist.rst b/doc/api/api_changes/2017-09-02-AL-rc-blacklist.rst
@@ -0,0 +1,7 @@
+Blacklisted rcparams no longer updated by `rcdefaults`, `rc_file_defaults`, `rc_file`
+-------------------------------------------------------------------------------------
+
+The rc modifier functions `rcdefaults`, `rc_file_defaults` and `rc_file`
+now ignore rcParams in the `matplotlib.style.core.STYLE_BLACKLIST` set.  In
+particular, this prevents the ``backend`` and ``interactive`` rcParams from
+being incorrectly modified by these functions.
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -1205,7 +1205,11 @@ def rc(group, **kwargs):
 
 
 def rcdefaults():
-    """Restore the rc params from Matplotlib's internal defaults.
+    """
+    Restore the rc params from Matplotlib's internal default style.
+
+    Style-blacklisted rc params (defined in
+    `matplotlib.style.core.STYLE_BLACKLIST`) are not updated.
 
     See Also
     --------
@@ -1219,29 +1223,42 @@ def rcdefaults():
     # no need to reemit them here.
     with warnings.catch_warnings():
         warnings.simplefilter("ignore", mplDeprecation)
+        from .style.core import STYLE_BLACKLIST
         rcParams.clear()
-        rcParams.update(rcParamsDefault)
+        rcParams.update({k: v for k, v in rcParamsDefault.items()
+                         if k not in STYLE_BLACKLIST})
 
 
 def rc_file_defaults():
-    """Restore the rc params from the original rc file loaded by Matplotlib.
+    """
+    Restore the rc params from the original rc file loaded by Matplotlib.
+
+    Style-blacklisted rc params (defined in
+    `matplotlib.style.core.STYLE_BLACKLIST`) are not updated.
     """
     # Deprecation warnings were already handled when creating rcParamsOrig, no
     # need to reemit them here.
     with warnings.catch_warnings():
         warnings.simplefilter("ignore", mplDeprecation)
-        rcParams.update(rcParamsOrig)
+        from .style.core import STYLE_BLACKLIST
+        rcParams.update({k: v for k, v in rcParamsOrig.items()
+                         if k not in STYLE_BLACKLIST})
 
 
 def rc_file(fname):
     """
     Update rc params from file.
+
+    Style-blacklisted rc params (defined in
+    `matplotlib.style.core.STYLE_BLACKLIST`) are not updated.
     """
     # Deprecation warnings were already handled in rc_params_from_file, no need
     # to reemit them here.
     with warnings.catch_warnings():
         warnings.simplefilter("ignore", mplDeprecation)
-        rcParams.update(rc_params_from_file(fname))
+        from .style.core import STYLE_BLACKLIST
+        rcParams.update({k: v for k, v in rc_params_from_file(fname).items()
+                         if k not in STYLE_BLACKLIST})
 
 
 class rc_context:
