Bug #1588217: don't parse "= " as a soft line break in binascii's

a2b_qp() function, instead leave it in the string as quopri.decode()
does.

Lib/test/test_binascii.py

@@ -134,7 +134,7 @@ class BinASCIITest(unittest.TestCase):
             pass
         else:
             self.fail("binascii.a2b_qp(**{1:1}) didn't raise TypeError")
-        self.assertEqual(binascii.a2b_qp("= "), "")
+        self.assertEqual(binascii.a2b_qp("= "), "= ")
         self.assertEqual(binascii.a2b_qp("=="), "=")
         self.assertEqual(binascii.a2b_qp("=AX"), "=AX")
         self.assertRaises(TypeError, binascii.b2a_qp, foo="bar")

Misc/NEWS

@@ -219,6 +219,10 @@ Library
 Extension Modules
 -----------------
 
+- Bug #1588217: don't parse "= " as a soft line break in binascii's
+  a2b_qp() function, instead leave it in the string as quopri.decode()
+  does.
+
 - Bug #1567666: Emulate GetFileAttributesExA for Win95.
 
 - Patch #1576166: Support os.utime for directories on Windows NT+.

Modules/binascii.c

@@ -1057,8 +1057,7 @@ binascii_a2b_qp(PyObject *self, PyObject *args, PyObject *kwargs)
 			in++;
 			if (in >= datalen) break;
 			/* Soft line breaks */
-			if ((data[in] == '\n') || (data[in] == '\r') ||
-			    (data[in] == ' ') || (data[in] == '\t')) {
+			if ((data[in] == '\n') || (data[in] == '\r')) {
 				if (data[in] != '\n') {
 					while (in < datalen && data[in] != '\n') in++;
 				}