Merged revisions 81098 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r81098 | antoine.pitrou | 2010-05-12 01:42:28 +0200 (mer., 12 mai 2010) | 5 lines

  Issue #8681: Make the zlib module's error messages more informative when
  the zlib itself doesn't give any detailed explanation.
........
diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index 9137f8a..1b802b8 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -134,6 +134,18 @@
         x = zlib.compress(data)
         self.assertEqual(zlib.decompress(x), data)
 
+    def test_incomplete_stream(self):
+        # An useful error message is given
+        x = zlib.compress(HAMLET_SCENE)
+        try:
+            zlib.decompress(x[:-1])
+        except zlib.error as e:
+            self.assertTrue(
+                "Error -5 while decompressing data: incomplete or truncated stream"
+                in str(e), str(e))
+        else:
+            self.fail("zlib.error not raised")
+
     # Memory use of the following functions takes into account overallocation
 
     @precisionbigmemtest(size=_1G + 1024 * 1024, memuse=3)