matplotlib · tacaswell · May 30, 2016 · Feb 23, 2016 · Feb 23, 2016 · Feb 23, 2016
diff --git a/lib/matplotlib/patches.py b/lib/matplotlib/patches.py
@@ -4063,7 +4063,7 @@ def __init__(self, posA=None, posB=None,
     def set_dpi_cor(self, dpi_cor):
         """
         dpi_cor is currently used for linewidth-related things and
-        shrink factor. Mutation scale is not affected by this.
+        shrink factor. Mutation scale is affected by this.
         """
 
         self._dpi_cor = dpi_cor
@@ -4072,7 +4072,7 @@ def set_dpi_cor(self, dpi_cor):
     def get_dpi_cor(self):
         """
         dpi_cor is currently used for linewidth-related things and
-        shrink factor. Mutation scale is not affected by this.
+        shrink factor. Mutation scale is affected by this.
         """
 
         return self._dpi_cor
@@ -4224,15 +4224,16 @@ def get_path_in_displaycoord(self):
                                                patchB=self.patchB,
                                                shrinkA=self.shrinkA * dpi_cor,
                                                shrinkB=self.shrinkB * dpi_cor
-                                              )
+                                               )
         else:
             _path = self.get_transform().transform_path(self._path_original)
 
-        _path, fillable = self.get_arrowstyle()(_path,
-                                                self.get_mutation_scale(),
-                                                self.get_linewidth() * dpi_cor,
-                                                self.get_mutation_aspect()
-                                               )
+        _path, fillable = self.get_arrowstyle()(
+                                        _path,
+                                        self.get_mutation_scale() * dpi_cor,
+                                        self.get_linewidth() * dpi_cor,
+                                        self.get_mutation_aspect()
+                                        )
 
         #if not fillable:
         #    self._fill = False
@@ -4542,13 +4543,14 @@ def get_path_in_displaycoord(self):
                                            patchB=self.patchB,
                                            shrinkA=self.shrinkA * dpi_cor,
                                            shrinkB=self.shrinkB * dpi_cor
-                                          )
-
-        _path, fillable = self.get_arrowstyle()(_path,
-                                                self.get_mutation_scale(),
-                                                self.get_linewidth() * dpi_cor,
-                                                self.get_mutation_aspect()
-                                               )
+                                           )
+
+        _path, fillable = self.get_arrowstyle()(
+                                        _path,
+                                        self.get_mutation_scale() * dpi_cor,
+                                        self.get_linewidth() * dpi_cor,
+                                        self.get_mutation_aspect()
+                                        )
 
         return _path, fillable
 

diff --git a/...tplotlib/tests/baseline_images/test_arrow_patches/fancyarrow_dpi_cor_100dpi.png b/...tplotlib/tests/baseline_images/test_arrow_patches/fancyarrow_dpi_cor_100dpi.png
diff --git a/...tplotlib/tests/baseline_images/test_arrow_patches/fancyarrow_dpi_cor_200dpi.png b/...tplotlib/tests/baseline_images/test_arrow_patches/fancyarrow_dpi_cor_200dpi.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/polar_axes.png b/lib/matplotlib/tests/baseline_images/test_axes/polar_axes.png
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/polar_coords.png b/lib/matplotlib/tests/baseline_images/test_axes/polar_coords.png
diff --git a/lib/matplotlib/tests/baseline_images/test_streamplot/streamplot_colormap.png b/lib/matplotlib/tests/baseline_images/test_streamplot/streamplot_colormap.png
diff --git a/lib/matplotlib/tests/baseline_images/test_streamplot/streamplot_linewidth.png b/lib/matplotlib/tests/baseline_images/test_streamplot/streamplot_linewidth.png
diff --git a/lib/matplotlib/tests/baseline_images/test_streamplot/streamplot_masks_and_nans.png b/lib/matplotlib/tests/baseline_images/test_streamplot/streamplot_masks_and_nans.png
diff --git a/lib/matplotlib/tests/baseline_images/test_streamplot/streamplot_startpoints.png b/lib/matplotlib/tests/baseline_images/test_streamplot/streamplot_startpoints.png
diff --git a/lib/matplotlib/tests/baseline_images/test_transforms/pre_transform_data.png b/lib/matplotlib/tests/baseline_images/test_transforms/pre_transform_data.png
diff --git a/lib/matplotlib/tests/test_arrow_patches.py b/lib/matplotlib/tests/test_arrow_patches.py
@@ -5,7 +5,7 @@
 
 import matplotlib.pyplot as plt
 from matplotlib.testing.decorators import image_comparison
-import matplotlib
+import matplotlib.patches as mpatches
 
 
 def draw_arrow(ax, t, r):
@@ -18,7 +18,7 @@ def draw_arrow(ax, t, r):
 def test_fancyarrow():
     # Added 0 to test division by zero error described in issue 3930
     r = [0.4, 0.3, 0.2, 0.1, 0]
-    t = ["fancy", "simple", matplotlib.patches.ArrowStyle.Fancy()]
+    t = ["fancy", "simple", mpatches.ArrowStyle.Fancy()]
 
     fig, axes = plt.subplots(len(t), len(r), squeeze=False,
                              subplot_kw=dict(aspect=True),
@@ -34,7 +34,7 @@ def test_fancyarrow():
 @image_comparison(baseline_images=['boxarrow_test_image'], extensions=['png'])
 def test_boxarrow():
 
-    styles = matplotlib.patches.BoxStyle.get_styles()
+    styles = mpatches.BoxStyle.get_styles()
 
     n = len(styles)
     spacing = 1.2
@@ -52,6 +52,51 @@ def test_boxarrow():
                   bbox=dict(boxstyle=stylename, fc="w", ec="k"))
 
 
+def __prepare_fancyarrow_dpi_cor_test():
+    """
+    Convenience function that prepares and returns a FancyArrowPatch. It aims
+    at being used to test that the size of the arrow head does not depend on
+    the DPI value of the exported picture.
+
+    NB: this function *is not* a test in itself!
+    """
+    fig2 = plt.figure("fancyarrow_dpi_cor_test", figsize=(4, 3), dpi=50)
+    ax = fig2.add_subplot(111)
+    ax.set_xlim([0, 1])
+    ax.set_ylim([0, 1])
+    ax.add_patch(mpatches.FancyArrowPatch(posA=(0.3, 0.4), posB=(0.8, 0.6),
+                                          lw=3, arrowstyle=u'->',
+                                          mutation_scale=100))
+    return fig2
+
+
+@image_comparison(baseline_images=['fancyarrow_dpi_cor_100dpi'],
+                  remove_text=True, extensions=['png'],
+                  savefig_kwarg=dict(dpi=100))
+def test_fancyarrow_dpi_cor_100dpi():
+    """
+    Check the export of a FancyArrowPatch @ 100 DPI. FancyArrowPatch is
+    instantiated through a dedicated function because another similar test
+    checks a similar export but with a different DPI value.
+
+    Remark: test only a rasterized format.
+    """
+
+    __prepare_fancyarrow_dpi_cor_test()
+
+
+@image_comparison(baseline_images=['fancyarrow_dpi_cor_200dpi'],
+                  remove_text=True, extensions=['png'],
+                  savefig_kwarg=dict(dpi=200))
+def test_fancyarrow_dpi_cor_200dpi():
+    """
+    As test_fancyarrow_dpi_cor_100dpi, but exports @ 200 DPI. The relative size
+    of the arrow head should be the same.
+    """
+
+    __prepare_fancyarrow_dpi_cor_test()
+
+
 if __name__ == '__main__':
     import nose
     nose.runmodule(argv=['-s', '--with-doctest'], exit=False)
diff --git a/lib/matplotlib/text.py b/lib/matplotlib/text.py
@@ -2147,7 +2147,6 @@ def _update_position_xytext(self, renderer, xy_pixel):
 
             d = self.arrowprops.copy()
             ms = d.pop("mutation_scale", self.get_size())
-            ms = renderer.points_to_pixels(ms)
             self.arrow_patch.set_mutation_scale(ms)
 
             if "arrowstyle" not in d:
@@ -2164,11 +2163,10 @@ def _update_position_xytext(self, renderer, xy_pixel):
                         " use 'headlength' to set the head length in points.")
                 headlength = d.pop('headlength', 12)
 
-                to_style = self.figure.dpi / (72 * ms)
-
-                stylekw = dict(head_length=headlength * to_style,
-                               head_width=headwidth * to_style,
-                               tail_width=width * to_style)
+                # NB: ms is in pts
+                stylekw = dict(head_length=headlength / ms,
+                               head_width=headwidth / ms,
+                               tail_width=width / ms)
 
                 self.arrow_patch.set_arrowstyle('simple', **stylekw)