MNT: deal with (0, 0) dashes.

tacaswell · tacaswell · commit ec4f168077f8 · 2016-07-12T08:21:00.000-05:00
diff --git a/lib/matplotlib/lines.py b/lib/matplotlib/lines.py
@@ -58,7 +58,9 @@ def _get_dash_pattern(style):
 
     # normalize offset to be positive and shorter than the dash cycle
     if dashes is not None and offset is not None:
-        offset %= sum(dashes)
+        dsum = sum(dashes)
+        if dsum:
+            offset %= dsum
 
     return offset, dashes
 
