Add documentation of colorbar issue matplotlib#1188 to colorbar docum…

…entation

lib/matplotlib/colorbar.py

@@ -174,6 +174,19 @@
 the axes objects in which the mappable and the colorbar are drawn.  In
 this case, do not use any of the axes properties kwargs.
 
+It is known that some vector graphics viewer (svg and pdf) renders white gaps
+between segments of the colorbar. This is due to bugs in the viewers not
+matplotlib. As a workaround the colorbar can be rendered with overlapping
+segments::
+
+    cbar = colorbar()
+    cbar.solids.set_edgecolor("face")
+    draw()
+
+However this has negative consequences in other circumstances. Particularly with
+semi transparent images (alpha < 1) and colorbar extensions and is not enabled
+by default see (issue #1188).
+
 returns:
     :class:`~matplotlib.colorbar.Colorbar` instance; see also its base class,
     :class:`~matplotlib.colorbar.ColorbarBase`.  Call the

lib/mpl_toolkits/axes_grid/colorbar.py

@@ -144,6 +144,19 @@
 the axes objects in which the mappable and the colorbar are drawn.  In
 this case, do not use any of the axes properties kwargs.
 
+It is known that some vector graphics viewer (svg and pdf) renders white gaps
+between segments of the colorbar. This is due to bugs in the viewers not
+matplotlib. As a workaround the colorbar can be rendered with overlapping
+segments::
+
+    cbar = colorbar()
+    cbar.solids.set_edgecolor("face")
+    draw()
+
+However this has negative consequences in other circumstances. Particularly with
+semi transparent images (alpha < 1) and colorbar extensions and is not enabled
+by default see (issue #1188).
+
 returns:
     :class:`~matplotlib.colorbar.Colorbar` instance; see also its base class,
     :class:`~matplotlib.colorbar.ColorbarBase`.  Call the

lib/mpl_toolkits/axes_grid1/colorbar.py

@@ -144,6 +144,19 @@
 the axes objects in which the mappable and the colorbar are drawn.  In
 this case, do not use any of the axes properties kwargs.
 
+It is known that some vector graphics viewer (svg and pdf) renders white gaps
+between segments of the colorbar. This is due to bugs in the viewers not
+matplotlib. As a workaround the colorbar can be rendered with overlapping
+segments::
+
+    cbar = colorbar()
+    cbar.solids.set_edgecolor("face")
+    draw()
+
+However this has negative consequences in other circumstances. Particularly with
+semi transparent images (alpha < 1) and colorbar extensions and is not enabled
+by default see (issue #1188).
+
 returns:
     :class:`~matplotlib.colorbar.Colorbar` instance; see also its base class,
     :class:`~matplotlib.colorbar.ColorbarBase`.  Call the