Work around another issue with libc++.

The same issue we had with operator== also exists with operator<,
namely that apparently the constructor of the one-past-the-end
object does not initialize the position within the row. This
fixes the problem in essentially the same way.

This should address the remaining failures referenced in #899.

diff --git a/include/deal.II/lac/dynamic_sparsity_pattern.h b/include/deal.II/lac/dynamic_sparsity_pattern.h
index d42bb76bb063589a95c7016ca642e919baac78dc..515b90fb530e9ec351c5c94e7f7c07e3ff3dc6ac 100644 (file)
--- a/include/deal.II/lac/dynamic_sparsity_pattern.h
+++ b/include/deal.II/lac/dynamic_sparsity_pattern.h
@@ -757,6 +757,18 @@ namespace DynamicSparsityPatternIterators
     Assert (sparsity_pattern == other.sparsity_pattern,
             ExcInternalError());
 
+    // compare the sparsity pattern the iterator points into, properly
+    // taking into account the one-past-the-end iterator state
+    if ((current_row < sparsity_pattern->n_rows())
+        &&
+        (other.current_row == numbers::invalid_unsigned_int))
+      return true;
+    if ((other.current_row < other.sparsity_pattern->n_rows())
+        &&
+        (current_row == numbers::invalid_unsigned_int))
+      return false;
+
+    // both iterators are not one-past-the-end
     return ((current_row < other.current_row) ||
             ((current_row == other.current_row) &&
              (current_entry < other.current_entry)));