From 1f49adf01ed06e320a401fd9129175d27bd1753e Mon Sep 17 00:00:00 2001
From: Jonathan Underwood <jonathan.underwood@gmail.com>
Date: Sat, 13 May 2017 12:54:08 +0100
Subject: [PATCH 1/3] Remove check for zero size in block compress (#27)

There are valid use cases for passing a zero length string
to compress:

https://github.com/python-lz4/python-lz4/issues/27
---
 lz4/block/_block.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/lz4/block/_block.c b/lz4/block/_block.c
index ac13ecd9..4a9f93ba 100644
--- a/lz4/block/_block.c
+++ b/lz4/block/_block.c
@@ -121,11 +121,6 @@ compress (PyObject * Py_UNUSED (self), PyObject * args, PyObject * kwargs)
       return NULL;
     }
 
-  if (source_size <= 0) {
-    PyErr_Format(PyExc_ValueError, "Input source data size invalid: %d bytes", source_size);
-    return NULL;
-  }
-
   if (!strncmp (mode, "default", sizeof ("default")))
     {
       comp = DEFAULT;

From 94c8473596cf4ff18403791566776dbb7d68faeb Mon Sep 17 00:00:00 2001
From: Jonathan Underwood <jonathan.underwood@gmail.com>
Date: Sat, 13 May 2017 13:01:19 +0100
Subject: [PATCH 2/3] Allow dest size of 0 in block decompress (#27)

---
 lz4/block/_block.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lz4/block/_block.c b/lz4/block/_block.c
index 4a9f93ba..a31b61fe 100644
--- a/lz4/block/_block.c
+++ b/lz4/block/_block.c
@@ -253,7 +253,7 @@ decompress (PyObject * Py_UNUSED (self), PyObject * args, PyObject * kwargs)
       source_size -= hdr_size;
     }
 
-  if (dest_size <= 0 || dest_size > PY_SSIZE_T_MAX)
+  if (dest_size < 0 || dest_size > PY_SSIZE_T_MAX)
     {
       PyErr_Format (PyExc_ValueError, "Invalid size in header: 0x%zu",
                     dest_size);

From 96f2a8988618977d1f0e6ac58a128fdd0bbf298a Mon Sep 17 00:00:00 2001
From: Jonathan Underwood <jonathan.underwood@gmail.com>
Date: Sat, 13 May 2017 13:01:54 +0100
Subject: [PATCH 3/3] Add test for zero size input for block
 compress/decompress (#27)

---
 tests/test_block.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tests/test_block.py b/tests/test_block.py
index 9be2c781..29f458a2 100644
--- a/tests/test_block.py
+++ b/tests/test_block.py
@@ -8,6 +8,10 @@
 
 class TestLZ4Block(unittest.TestCase):
 
+    def test_empty_string(self):
+      DATA = b''
+      self.assertEqual(DATA, lz4.block.decompress(lz4.block.compress(DATA)))
+
     def test_random(self):
       DATA = os.urandom(128 * 1024)  # Read 128kb
       self.assertEqual(DATA, lz4.block.decompress(lz4.block.compress(DATA)))