backend_pgf: don't clip filled paths (fixes matplotlib#2885, matplotlib#3935, matplotlib#3693)

Author: pwuertz

lib/matplotlib/backends/backend_pgf.py

@@ -478,7 +478,7 @@ def draw_path(self, gc, path, transform, rgbFace=None):
         # draw the path
         self._print_pgf_clip(gc)
         self._print_pgf_path_styles(gc, rgbFace)
-        self._print_pgf_path(gc, path, transform)
+        self._print_pgf_path(gc, path, transform, rgbFace)
         self._pgf_path_draw(stroke=gc.get_linewidth() != 0.0,
                             fill=rgbFace is not None)
         writeln(self.fh, r"\end{pgfscope}")
@@ -584,11 +584,11 @@ def _print_pgf_path_styles(self, gc, rgbFace):
             dash_str += r"}{%fpt}" % dash_offset
             writeln(self.fh, dash_str)
 
-    def _print_pgf_path(self, gc, path, transform):
+    def _print_pgf_path(self, gc, path, transform, rgbFace=None):
         f = 1. / self.dpi
-        # check for clip box
+        # check for clip box / ignore clip for filled paths
         bbox = gc.get_clip_rectangle() if gc else None
-        if bbox:
+        if bbox and (rgbFace is None):
             p1, p2 = bbox.get_points()
             clip = (p1[0], p1[1], p2[0], p2[1])
         else:

lib/matplotlib/tests/baseline_images/test_backend_pgf/pgf_pdflatex.pdf

@@ -73,16 +73,28 @@ def compare_figure(fname, savefig_kwargs={}):
 def create_figure():
     plt.figure()
     x = np.linspace(0, 1, 15)
+
+    # line plot
     plt.plot(x, x ** 2, "b-")
+
+    # marker
+    plt.plot(x, 1 - x**2, "g>")
+
+    # filled paths and patterns
     plt.fill_between([0., .4], [.4, 0.], hatch='//', facecolor="lightgray",
                      edgecolor="red")
-    plt.plot(x, 1 - x**2, "g>")
+    plt.fill([3, 3, .8, .8, 3], [2, -2, -2, 0, 2], "b")
+
+    # text and typesetting
     plt.plot([0.9], [0.5], "ro", markersize=3)
     plt.text(0.9, 0.5, 'unicode (ü, °, µ) and math ($\\mu_i = x_i^2$)',
              ha='right', fontsize=20)
     plt.ylabel('sans-serif, blue, $\\frac{\\sqrt{x}}{y^2}$..',
                family='sans-serif', color='blue')
 
+    plt.xlim(0, 1)
+    plt.ylim(0, 1)
+
 
 # test compiling a figure to pdf with xelatex
 @switch_backend('pgf')