Tests for permitted libtiff metadata

PIL/TiffTags.py

@@ -386,4 +386,17 @@ LIBTIFF_CORE = set ([255, 256, 257, 258, 259, 262, 263, 266, 274, 277,
                      269 # this has been in our tests forever, and works
                      ])
 
-LIBTIFF_CORE.remove(320) # Arrays error? 
+LIBTIFF_CORE.remove(320) # Array of short, crashes
+LIBTIFF_CORE.remove(301) # Array of short, crashes
+LIBTIFF_CORE.remove(532) # Array of long, crashes
+
+LIBTIFF_CORE.remove(255) # We don't have support for subfiletypes
+LIBTIFF_CORE.remove(322) # We don't have support for tiled images in libtiff
+LIBTIFF_CORE.remove(323) # Tiled images
+LIBTIFF_CORE.remove(333) # Ink Names either
+
+# Note to advanced users: There may be combinations of these
+# parameters and values that when added properly, will work and
+# produce valid tiff images that may work in your application.
+# It is safe to add and remove tags from this set from Pillow's point
+# of view so long as you test against libtiff.

Tests/test_file_libtiff.py

@@ -7,7 +7,7 @@ import logging
 import itertools
 import os
 
-from PIL import Image, TiffImagePlugin
+from PIL import Image, TiffImagePlugin, TiffTags
 
 logger = logging.getLogger(__name__)
 
@@ -172,6 +172,59 @@ class TestFileLibTiff(LibTiffTestCase):
             for field in requested_fields:
                 self.assertTrue(field in reloaded, "%s not in metadata" %field)
 
+    def test_additional_metadata(self):
+        # these should not crash. Seriously dummy data, most of it doesn't make
+        # any sense, so we're running up against limits where we're asking
+        # libtiff to do stupid things.
+        
+        # Get the list of the ones that we should be able to write
+
+        core_items = dict((tag, info) for tag, info in [(s,TiffTags.lookup(s)) for s
+                                                        in TiffTags.LIBTIFF_CORE]
+                          if info.type is not None)
+        
+        # Exclude ones that have special meaning that we're already testing them
+        im = Image.open('Tests/images/hopper_g4.tif')
+        for tag in im.tag_v2.keys():
+            try:
+                del(core_items[tag])
+            except: pass
+
+        # Type codes:
+        #     2: "ascii",
+        #     3: "short",
+        #     4: "long",
+        #     5: "rational",
+        #     12: "double",
+        # type: dummy value
+        values = { 2: 'test',
+                   3: 1,
+                   4: 2**20,
+                   5: TiffImagePlugin.IFDRational(100,1),
+                   12: 1.05 }
+
+
+        new_ifd = TiffImagePlugin.ImageFileDirectory_v2()
+        for tag, info in core_items.items():
+            if info.length == 1:
+                new_ifd[tag] = values[info.type]
+            if info.length == 0:
+                new_ifd[tag] = tuple(values[info.type] for _ in range(3))
+            else:
+                new_ifd[tag] = tuple(values[info.type] for _ in range(info.length))
+
+        # Extra samples really doesn't make sense in this application. 
+        del(new_ifd[338])
+
+        out = self.tempfile("temp.tif")
+        TiffImagePlugin.WRITE_LIBTIFF = True
+
+        im.save(out, tiffinfo=new_ifd)
+        
+        TiffImagePlugin.WRITE_LIBTIFF = False
+
+
+
     def test_g3_compression(self):
         i = Image.open('Tests/images/hopper_g4_500.tif')
         out = self.tempfile("temp.tif")