Handle non-ascii characters properly in scancode-fingerprint #1690

Signed-off-by: Steven Esser <[email protected]>

Author: steven-esser

plugins/scancode-fingerprint/src/plugin_fingerprint/fingerprint.py

@@ -25,9 +25,11 @@
 import binascii
 from bitarray import bitarray
 from bitarray import bitdiff
-from licensedcode.tokenize import ngrams
 import hashlib
 
+from commoncode.text import toascii
+from licensedcode.tokenize import ngrams
+
 HASH_LENGTH = 128
 SHINGLE_LENGTH = 3
 
@@ -103,6 +105,9 @@ def process_shingles(self, shingle, weighted_list):
         """
         Modify weighted list wrt to shingle
         """
+        # convert other encodings to ascii. See #1690.
+        shingle = toascii(shingle)
+        
         hash = hashlib.md5(shingle.encode()).digest()
         result = self.bitarray_from_bytes(hash)
 

plugins/scancode-fingerprint/tests/test_fingerprint.py

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 #
 # Copyright (c) nexB Inc. and others. All rights reserved.
 # http://nexb.com and https://github.com/nexB/scancode-toolkit/
@@ -131,10 +132,18 @@ def test_hex_digest3(self):
         result = simhash.hex_digest()
         assert result == '7f43e1b18f9c0e705fcf28007bc41754'
 
-    def test_hex_digest3(self):
+    def test_hex_digest4(self):
         simhash = Simhash()
         assert simhash.hex_digest() == None
 
+    # Ensure non-ascii characters are handled properly. See #1690.
+    def test_hex_digest_non_ascii(self):
+        simhash = Simhash()
+        simhash.update('Copyright (c) Mário Morgado')
+
+        result = simhash.hex_digest()
+        assert result == '01010040c1300a05ce41804024000001'
+
     def test_update(self):
         simhash = Simhash()
         assert simhash.tokens == []
@@ -152,6 +161,14 @@ def test_generate_fingerprint(self):
         simhash.update('this will get added too!')
         expected = bitarray('00000010000000000011110010100000101000001111100000000001010110000110101110111000100000110101000000010100100000000010110011010010')
         assert simhash.generate_fingerprint() == expected
+    
+    # Ensure non-ascii characters are handled properly. See #1690.
+    def test_generate_fingerprint_non_ascii(self):
+        simhash = Simhash()
+        simhash.update('Copyright (c) Mário Morgado')
+
+        expected = bitarray('00000001000000010000000001000000110000010011000000001010000001011100111001000001100000000100000000100100000000000000000000000001')
+        assert simhash.generate_fingerprint() == expected
 
     def test_similarity_matching1(self):
         simhash1 = Simhash()