[pypy-commit] pypy default: Handle weird indices here, don't try to pass length = -1 down to append_charpsize

[alex_gaynor]

Author: Alex Gaynor <alex.gaynor at gmail.com>
Branch: 
Changeset: r67862:cab5c44a5677
Date: 2013-11-05 22:31 -0800
http://bitbucket.org/pypy/pypy/changeset/cab5c44a5677/

Log:	Handle weird indices here, don't try to pass length = -1 down to
	append_charpsize

diff --git a/pypy/module/mmap/interp_mmap.py b/pypy/module/mmap/interp_mmap.py
--- a/pypy/module/mmap/interp_mmap.py
+++ b/pypy/module/mmap/interp_mmap.py
@@ -163,6 +163,8 @@
         if step == 0:  # index only
             return space.wrap(self.mmap.getitem(start))
         elif step == 1:
+            if stop - start < 0:
+                return space.wrap("")
             return space.wrap(self.mmap.getslice(start, stop - start))
         else:
             res = "".join([self.mmap.getitem(i)
diff --git a/pypy/module/mmap/test/test_mmap.py b/pypy/module/mmap/test/test_mmap.py
--- a/pypy/module/mmap/test/test_mmap.py
+++ b/pypy/module/mmap/test/test_mmap.py
@@ -525,6 +525,8 @@
         m = mmap(f.fileno(), 6)
         assert m[-3:7] == "bar"
 
+        assert m[1:0:1] == ""
+
         f.close()
 
     def test_sequence_type(self):
diff --git a/rpython/rlib/rstring.py b/rpython/rlib/rstring.py
--- a/rpython/rlib/rstring.py
+++ b/rpython/rlib/rstring.py
@@ -371,6 +371,7 @@
         self._grow(times)
 
     def append_charpsize(self, s, size):
+        assert size >= 0
         l = []
         for i in xrange(size):
             l.append(s[i])