[pypy-svn] pypy default: Fixes for io.StringIO.{tell,seek}.

[alex_gaynor]

Author: Alex Gaynor <alex.gaynor at gmail.com>
Branch: 
Changeset: r41461:eb35134b52d5
Date: 2011-01-29 13:48 -0500
http://bitbucket.org/pypy/pypy/changeset/eb35134b52d5/

Log:	Fixes for io.StringIO.{tell,seek}.

diff --git a/pypy/module/_io/interp_textio.py b/pypy/module/_io/interp_textio.py
--- a/pypy/module/_io/interp_textio.py
+++ b/pypy/module/_io/interp_textio.py
@@ -191,7 +191,7 @@
     setstate = interp2app(W_IncrementalNewlineDecoder.setstate_w),
 
     newlines = GetSetProperty(W_IncrementalNewlineDecoder.newlines_get_w),
-    )
+)
 
 class W_TextIOBase(W_IOBase):
     w_encoding = None

diff --git a/pypy/module/_io/test/test_stringio.py b/pypy/module/_io/test/test_stringio.py
--- a/pypy/module/_io/test/test_stringio.py
+++ b/pypy/module/_io/test/test_stringio.py
@@ -52,6 +52,27 @@
         exc_info = raises(ValueError, sio.seek, -3)
         assert exc_info.value.args[0] == "negative seek position: -3"
 
+        raises(ValueError, sio.seek, 3, -1)
+        raises(ValueError, sio.seek, 3, -3)
+
+        sio.close()
+        raises(ValueError, sio.seek, 0)
+
+    def test_tell(self):
+        import io
+
+        s = u"1234567890"
+        sio = io.StringIO(s)
+
+        assert sio.tell() == 0
+        sio.seek(5)
+        assert sio.tell() == 5
+        sio.seek(10000)
+        assert sio.tell() == 10000
+
+        sio.close()
+        raises(ValueError, sio.tell)
+
     def test_write_error(self):
         import io
 

diff --git a/pypy/module/_io/interp_stringio.py b/pypy/module/_io/interp_stringio.py
--- a/pypy/module/_io/interp_stringio.py
+++ b/pypy/module/_io/interp_stringio.py
@@ -6,6 +6,7 @@
 from pypy.module._io.interp_textio import W_TextIOBase
 from pypy.module._io.interp_iobase import convert_size
 
+
 class W_StringIO(W_TextIOBase):
     def __init__(self, space):
         W_TextIOBase.__init__(self, space)
@@ -74,13 +75,30 @@
         self.pos = end
         return space.wrap(u''.join(self.buf[start:end]))
 
-    @unwrap_spec('self', ObjSpace, int)
-    def seek_w(self, space, pos):
-        if pos < 0:
+    @unwrap_spec('self', ObjSpace, int, int)
+    def seek_w(self, space, pos, mode=0):
+        self._check_closed(space)
+
+        if not 0 <= mode <= 2:
+            raise operationerrfmt(space.w_ValueError,
+                "Invalid whence (%d, should be 0, 1 or 2)", mode
+            )
+        elif mode == 0 and pos < 0:
             raise operationerrfmt(space.w_ValueError,
                 "negative seek position: %d", pos
             )
+        elif mode != 0 and pos != 0:
+            raise OperationError(space.w_IOError,
+                space.wrap("Can't do nonzero cur-relative seeks")
+            )
+
+        # XXX: this makes almost no sense, but its how CPython does it.
+        if mode == 1:
+            pos = self.pos
+        elif mode == 2:
+            pos = len(self.buf)
         self.pos = pos
+        return space.wrap(pos)
 
     @unwrap_spec('self', ObjSpace)
     def getvalue_w(self, space):