force seek to beginning of file

Tests/test_file_tiff.py

@@ -114,17 +114,6 @@ def test_g4_tiff_bytesio():
     assert_equal(im.size, (500,500))
     _assert_noerr(im)
     	
-def xtest_g4_tiff_fail(): # UNDONE fails badly, unknown reason
-    """The 128x128 lena image fails for some reason. Investigating"""
-
-    Image.DEBUG = True
-    file = "Tests/images/lena_g4.tif"
-    im = Image.open(file)
-
-    assert_equal(im.size, (128,128))
-    _assert_noerr(im)
-    Image.DEBUG = False
-        
 def test_g4_eq_png():
     """ Checking that we're actually getting the data that we expect"""
     png = Image.open('Tests/images/lena_bw_500.png')
@@ -134,7 +123,6 @@ def test_g4_eq_png():
 
 def test_g4_write():
     """Checking to see that the saved image is the same as what we wrote"""
-    Image.DEBUG = True
 
     file = "Tests/images/lena_g4_500.tif"
     orig = Image.open(file)
@@ -151,4 +139,3 @@ def test_g4_write():
 
     assert_false(orig.tobytes() == reread.tobytes())
 
-    Image.DEBUG = False

Tests/test_lena.py

@@ -0,0 +1,47 @@
+from tester import *
+
+from PIL import Image
+
+from test_file_tiff import _assert_noerr
+
+""" The small lena image was failing on open in the libtiff
+    decoder because the file pointer was set to the wrong place
+    by a spurious seek. It wasn't failing with the byteio method.
+
+    It was fixed by forcing an lseek to the beginning of the
+    file just before reading in libtiff. These tests remain
+    to ensure that it stays fixed. """
+
+
+def test_g4_lena_file(): 
+    """Testing the open file load path"""
+
+    file = "Tests/images/lena_g4.tif"
+    with open(file,'rb') as f:
+        im = Image.open(f)
+
+        assert_equal(im.size, (128,128))
+        _assert_noerr(im)
+
+def test_g4_lena_bytesio(): 
+    """Testing the bytesio loading code path"""
+    from io import BytesIO
+    file = "Tests/images/lena_g4.tif"
+    s = BytesIO()
+    with open(file,'rb') as f:
+        s.write(f.read())
+        s.seek(0)
+    im = Image.open(s)
+
+    assert_equal(im.size, (128,128))
+    _assert_noerr(im)
+        
+def test_g4_lena(): 
+    """The 128x128 lena image fails for some reason. Investigating"""
+
+    file = "Tests/images/lena_g4.tif"
+    im = Image.open(file)
+
+    assert_equal(im.size, (128,128))
+    _assert_noerr(im)
+        

libImaging/TiffDecode.c

@@ -199,6 +199,7 @@ int ImagingLibTiffDecode(Imaging im, ImagingCodecState state, UINT8* buffer, int
 	dump_state(clientstate);
 	if (clientstate->fp) {
 		TRACE(("Opening using fd: %d\n",clientstate->fp));
+		lseek(clientstate->fp,0,SEEK_SET); // Sometimes, I get it set to the end.
 		tiff = TIFFFdOpen(clientstate->fp, filename, mode);
 	} else {  
 		TRACE(("Opening from string\n"));

libImaging/TiffDecode.h

@@ -13,6 +13,11 @@
 #include <tiff.h>
 #endif
 
+#ifndef _UNISTD_H
+#include <unistd.h>
+#endif
+
+
 #ifndef min
 #define min(x,y) (( x > y ) ? y : x )
 #define max(x,y) (( x < y ) ? y : x )
@@ -50,8 +55,8 @@ extern int ImagingLibTiffSetField(ImagingCodecState state, ttag_t tag, ...);
 /* 
 #define TRACE(args)
 */
-#endif
+#endif /* _MSC_VER */
 
 
 
-#endif
+#endif