Fix an infinite recursion in the unit registry when trying to find a converter for a sequence of strings. Add a test for this to unit/nose_tests.py

svn path=/trunk/matplotlib/; revision=6798

Author: dopplershift

CHANGELOG

@@ -1,8 +1,12 @@
-2009-11-16 Bugfix of C typedef of MPL_Int64 that was failing on
+2009-01-16 Fix an infinite recursion in the unit registry when searching
+           for a converter for a sequence of strings. Add a corresponding
+           test. - RM
+
+2009-01-16 Bugfix of C typedef of MPL_Int64 that was failing on
            Windows XP 64 bit, as reported by George Goussard on numpy
            mailing list. - ADS
 
-2009-11-16 Added helper function LinearSegmentedColormap.from_list to
+2009-01-16 Added helper function LinearSegmentedColormap.from_list to
            facilitate building simple custom colomaps.  See
            examples/pylab_examples/custom_cmap_fromlist.py - JDH
 

lib/matplotlib/units.py

@@ -44,7 +44,7 @@ def default_units(x):
 
 """
 import numpy as np
-from matplotlib.cbook import iterable, is_numlike
+from matplotlib.cbook import iterable, is_numlike, is_string_like
 
 class AxisInfo:
     'information to support default axis labeling and tick labeling'
@@ -127,7 +127,10 @@ def get_converter(self, x):
         if classx is not None:
             converter = self.get(classx)
 
-        if converter is None and iterable(x):
+        # Check explicity for strings here because they would otherwise
+        # lead to an infinite recursion, because a single character will
+        # pass the iterable() check.
+        if converter is None and iterable(x) and not is_string_like(x):
             # if this is anything but an object array, we'll assume
             # there are no custom units
             if isinstance(x, np.ndarray) and x.dtype != np.object:

unit/nose_tests.py

@@ -40,6 +40,17 @@ def test_markevery():
     fig.canvas.draw()
     plt.close(fig)
 
+def test_units_strings():
+    # Make sure passing in sequences of strings doesn't cause the unit
+    # conversion registry to recurse infinitely
+    Id = ['50', '100', '150', '200', '250']
+    pout = ['0', '7.4', '11.4', '14.2', '16.3']
+    fig = plt.figure()
+    ax = fig.add_subplot(111)
+    ax.plot(Id, pout)
+    fig.canvas.draw()
+    plt.close(fig)
+
 if __name__=='__main__':
     nose.runmodule(argv=['-s','--with-doctest'], exit=False)