Minor fix - check for ragged array length when exporting to hdf5

pyqtgraph/exporters/HDF5Exporter.py

@@ -44,12 +44,18 @@ class HDF5Exporter(Exporter):
         data = []
 
         appendAllX = self.params['columnMode'] == '(x,y) per plot'
+        #print dir(self.item.curves[0])
+        tlen = 0
         for i, c in enumerate(self.item.curves):
             d = c.getData()
+            if i > 0 and len(d[0]) != tlen:
+                raise ValueError ("HDF5 Export requires all curves in plot to have same length")
             if appendAllX or i == 0:
                 data.append(d[0])
+                tlen = len(d[0])
             data.append(d[1])
 
+
         fdata = numpy.array(data).astype('double')
         dset = fd.create_dataset(dsname, data=fdata)
         fd.close()