Nan issue in text.py

[ffteja]

In text.py, in function "draw", the values returned by the line "posx, posy = trans.transform_point((posx, posy))" can set Nan values into posx and pos variables. Thus, the following test in the function "if not np.isfinite(x) or not np.isfinite(y):" is too early as "x = x + posx" is called afterwards. Thus it wil crashes in the following call to the draw_text function :

The following python error occurred:
        ValueError('cannot convert float NaN to integer',)
File "/lib/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 198, in draw_text
        font.get_image(), np.round(x - xd), np.round(y + yd) + 1, angle, gc)

Please find the patch below that just moves the test :

Index: /matplotlib-1.4.0/lib/matplotlib/text.py
===================================================================
--- /matplotlib-1.4.0/lib/matplotlib/text.py    (révision 78983)
+++ /matplotlib-1.4.0/lib/matplotlib/text.py    (copie de travail)
@@ -561,14 +561,15 @@
         angle = self.get_rotation()

         for line, wh, x, y in info:
-            if not np.isfinite(x) or not np.isfinite(y):
-                continue
-
             mtext = self if len(info) == 1 else None
             x = x + posx
             y = y + posy
             if renderer.flipy():
                 y = canvash - y
+                
+            if not np.isfinite(x) or not np.isfinite(y):
+                continue
+
             clean_line, ismath = self.is_math_text(line)

             if self.get_path_effects():

You can reproduce this configuration by zooming in a polar plot.

[tac edited for markup]

[tacaswell]

@ffteja Can you make a pull request with that patch applied? Doing so makes it a bit easier on us to review (which in this case isn't a huge deal) and makes sure you get credit for your contribution.