diff -r cd87afe18ff8 Lib/lzma.py
--- a/Lib/lzma.py	Wed Jan 23 08:38:47 2013 -0500
+++ b/Lib/lzma.py	Thu Jan 24 09:29:40 2013 +0200
@@ -112,6 +112,7 @@
             self._decompressor = LZMADecompressor(**self._init_args)
             self._buffer = b""
             self._buffer_offset = 0
+            self._error = None
         elif mode in ("w", "wb", "a", "ab"):
             if format is None:
                 format = FORMAT_XZ
@@ -207,30 +208,40 @@
                                           "does not support seeking")
 
     # Fill the readahead buffer if it is empty. Returns False on EOF.
-    def _fill_buffer(self):
+    def _fill_buffer(self, weak=False):
         if self._mode == _MODE_READ_EOF:
             return False
-        # Depending on the input data, our call to the decompressor may not
-        # return any data. In this case, try again after reading another block.
-        while self._buffer_offset == len(self._buffer):
-            rawblock = (self._decompressor.unused_data or
-                        self._fp.read(_BUFFER_SIZE))
+        if self._error is not None:
+            err = self._error
+            self._error = None
+            raise err
+        try:
+            # Depending on the input data, our call to the decompressor may not
+            # return any data. In this case, try again after reading another block.
+            while self._buffer_offset == len(self._buffer):
+                rawblock = (self._decompressor.unused_data or
+                            self._fp.read(_BUFFER_SIZE))
 
-            if not rawblock:
+                if not rawblock:
+                    if self._decompressor.eof:
+                        self._mode = _MODE_READ_EOF
+                        self._size = self._pos
+                        return False
+                    else:
+                        raise EOFError("Compressed file ended before the "
+                                    "end-of-stream marker was reached")
+
+                # Continue to next stream.
                 if self._decompressor.eof:
-                    self._mode = _MODE_READ_EOF
-                    self._size = self._pos
-                    return False
-                else:
-                    raise EOFError("Compressed file ended before the "
-                                   "end-of-stream marker was reached")
+                    self._decompressor = LZMADecompressor(**self._init_args)
 
-            # Continue to next stream.
-            if self._decompressor.eof:
-                self._decompressor = LZMADecompressor(**self._init_args)
-
-            self._buffer = self._decompressor.decompress(rawblock)
-            self._buffer_offset = 0
+                self._buffer = self._decompressor.decompress(rawblock)
+                self._buffer_offset = 0
+        except (EOFError, LZMAError) as err:
+            if weak:
+                self._error = err
+                return False
+            raise
         return True
 
     # Read data until EOF.
@@ -241,7 +252,7 @@
         self._buffer_offset = 0
 
         blocks = []
-        while self._fill_buffer():
+        while self._fill_buffer(blocks):
             if return_data:
                 blocks.append(self._buffer)
             self._pos += len(self._buffer)
@@ -265,7 +276,7 @@
         self._buffer_offset = 0
 
         blocks = []
-        while n > 0 and self._fill_buffer():
+        while n > 0 and self._fill_buffer(blocks):
             if n < len(self._buffer):
                 data = self._buffer[:n]
                 self._buffer_offset = n
@@ -318,7 +329,7 @@
             # Only call _fill_buffer() if the buffer is actually empty.
             # This gives a significant speedup if *size* is small.
             (self._buffer_offset == len(self._buffer) and not self._fill_buffer())):
-            return b""
+                return b""
         if size > 0:
             data = self._buffer[self._buffer_offset :
                                 self._buffer_offset + size]
@@ -369,6 +380,7 @@
         self._decompressor = LZMADecompressor(**self._init_args)
         self._buffer = b""
         self._buffer_offset = 0
+        self._error = None
 
     def seek(self, offset, whence=0):
         """Change the file position.
diff -r cd87afe18ff8 Lib/test/test_lzma.py
--- a/Lib/test/test_lzma.py	Wed Jan 23 08:38:47 2013 -0500
+++ b/Lib/test/test_lzma.py	Thu Jan 24 09:29:40 2013 +0200
@@ -667,6 +667,9 @@
 
     def test_read_incomplete(self):
         with LZMAFile(BytesIO(COMPRESSED_XZ[:128])) as f:
+            res = f.read()
+            self.assertIn(res, INPUT)
+            self.assertTrue(INPUT.startswith(res))
             self.assertRaises(EOFError, f.read)
 
     def test_read_truncated(self):
@@ -674,10 +677,14 @@
         # flags (2 bytes) and magic number (2 bytes).
         truncated = COMPRESSED_XZ[:-12]
         with LZMAFile(BytesIO(truncated)) as f:
+            self.assertEqual(f.read(), INPUT)
             self.assertRaises(EOFError, f.read)
         with LZMAFile(BytesIO(truncated)) as f:
             self.assertEqual(f.read(len(INPUT)), INPUT)
             self.assertRaises(EOFError, f.read, 1)
+        with LZMAFile(BytesIO(truncated)) as f:
+            self.assertEqual(f.read(len(INPUT) + 1), INPUT)
+            self.assertRaises(EOFError, f.read, 1)
         # Incomplete 12-byte header.
         for i in range(12):
             with LZMAFile(BytesIO(truncated[:i])) as f: