Preserve the default values of the metadata. Allow user to update if necessary

Xarthisius · Xarthisius · commit 12b0120d8d56 · 2016-12-25T07:53:26.000-06:00
diff --git a/lib/matplotlib/backends/backend_agg.py b/lib/matplotlib/backends/backend_agg.py
@@ -554,14 +554,16 @@ def print_png(self, filename_or_obj, *args, **kwargs):
         else:
             close = False
 
-        metadata = kwargs.pop("metadata", None)
-        if metadata is None:
-            version_str = 'matplotlib version ' + __version__ + \
-                ', http://matplotlib.org/'
-            metadata = {six.b('Software'): six.b(version_str)}
+        version_str = 'matplotlib version ' + __version__ + \
+            ', http://matplotlib.org/'
+        metadata = {six.b('Software'): six.b(version_str)}
+        user_metadata = kwargs.pop("metadata", None)
+        if user_metadata is not None:
+            metadata.update(user_metadata)
+
         try:
-            _png.write_png(renderer._renderer, filename_or_obj, self.figure.dpi,
-                           metadata=metadata)
+            _png.write_png(renderer._renderer, filename_or_obj,
+                           self.figure.dpi, metadata=metadata)
         finally:
             if close:
                 filename_or_obj.close()
diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
@@ -482,15 +482,14 @@ def __init__(self, filename, metadata=None):
         else:
             source_date = datetime.today()
 
+        self.infoDict = {
+            'Creator': 'matplotlib ' + __version__ +
+                       ', http://matplotlib.org',
+            'Producer': 'matplotlib pdf backend%s' % revision,
+            'CreationDate': source_date
+        }
         if metadata is not None:
-            self.infoDict = metadata
-        else:
-            self.infoDict = {
-                'Creator': 'matplotlib ' + __version__ +
-                           ', http://matplotlib.org',
-                'Producer': 'matplotlib pdf backend%s' % revision,
-                'CreationDate': source_date
-            }
+            self.infoDict.update(metadata)
 
         self.fontNames = {}     # maps filenames to internal font names
         self.nextFont = 1       # next free internal font name
