Issue #7701: Fix crash in binascii.b2a_uu() in debug mode when given a

1-byte argument.  Patch by Victor Stinner.

Lib/test/test_binascii.py

@@ -109,6 +109,9 @@ class BinASCIITest(unittest.TestCase):
 
         self.assertRaises(binascii.Error, binascii.b2a_uu, 46*"!")
 
+        # Issue #7701 (crash on a pydebug build)
+        self.assertEqual(binascii.b2a_uu('x'), '!>   \n')
+
     def test_crc32(self):
         crc = binascii.crc32("Test the CRC-32 of")
         crc = binascii.crc32(" this string.", crc)

Misc/NEWS

@@ -33,6 +33,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #7701: Fix crash in binascii.b2a_uu() in debug mode when given a
+  1-byte argument.  Patch by Victor Stinner.
+
 - Issue #3299: Fix possible crash in the _sre module when given bad
   argument values in debug mode.  Patch by Victor Stinner.
 

Modules/binascii.c

@@ -294,7 +294,7 @@ binascii_b2a_uu(PyObject *self, PyObject *args)
 	}
 
 	/* We're lazy and allocate to much (fixed up later) */
-	if ( (rv=PyString_FromStringAndSize(NULL, bin_len*2+2)) == NULL ) {
+	if ( (rv=PyString_FromStringAndSize(NULL, 2 + (bin_len+2)/3*4)) == NULL ) {
 		PyBuffer_Release(&pbin);
 		return NULL;
 	}