Fix the doc build hanging (based on a report by Sandro Tosi).

Author: mdboom

doc/make.py

@@ -138,7 +138,7 @@ def html():
         options = "-D plot_formats=\"[('png', 80)]\""
     else:
         options = ''
-    if os.system('sphinx-build %s -P -b html -d build/doctrees . build/html' % options):
+    if os.system('sphinx-build %s -b html -d build/doctrees . build/html' % options):
         raise SystemExit("Building HTML failed.")
 
     figures_dest_path = 'build/html/pyplots'

lib/matplotlib/sphinxext/plot_directive.py

@@ -498,7 +498,10 @@ def render_figures(code, code_path, output_dir, output_base, context,
     # -- Parse format list
     default_dpi = {'png': 80, 'hires.png': 200, 'pdf': 200}
     formats = []
-    for fmt in config.plot_formats:
+    plot_formats = config.plot_formats
+    if isinstance(plot_formats, (str, unicode)):
+        plot_formats = eval(plot_formats)
+    for fmt in plot_formats:
         if isinstance(fmt, str):
             formats.append((fmt, default_dpi.get(fmt, 80)))
         elif type(fmt) in (tuple, list) and len(fmt)==2:
@@ -584,6 +587,9 @@ def render_figures(code, code_path, output_dir, output_base, context,
 
         results.append((code_piece, images))
 
+    if not context:
+        clear_state(config.plot_rcparams)
+
     return results
 
 def run(arguments, content, options, state_machine, state, lineno):