From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Fri, 11 Feb 2022 10:40:22 +0000 (+1100)
Subject: fix incorrect clearing of bits in bitarray
X-Git-Tag: 3.0.0~31^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7b945c57b1d8148c7c736271c8c5f8b8c796fce9;p=graphviz

fix incorrect clearing of bits in bitarray

The wrong bitwise operations were used here, resulting in e.g. a set of bit 2 of
of `0b011000` updating to `0b011100` instead of being a no-op.

This bug was present since the first introduction of this interface in
3ced90bd756bb8e56920620f2686e0ba6b482bbb, but this has not yet made it into a
release.
---

diff --git a/lib/cgraph/bitarray.h b/lib/cgraph/bitarray.h
index bf9564275..6aa7fb7d7 100644
--- a/lib/cgraph/bitarray.h
+++ b/lib/cgraph/bitarray.h
@@ -113,7 +113,7 @@ static inline void bitarray_set(bitarray_t *self, size_t index, bool value) {
   if (value) {
     base[index / 8] |= (uint8_t)(UINT8_C(1) << (index % 8));
   } else {
-    base[index / 8] ^= (uint8_t)(UINT8_C(1) << (index % 8));
+    base[index / 8] &= (uint8_t)~(UINT8_C(1) << (index % 8));
   }
 }
 
diff --git a/rtest/test_regression.py b/rtest/test_regression.py
index 7f203084c..01128fa9f 100644
--- a/rtest/test_regression.py
+++ b/rtest/test_regression.py
@@ -1516,7 +1516,6 @@ def test_gvmap_fclose():
   # pass this through gvmap
   subprocess.run(["gvmap"], input=input.encode("utf-8"), check=True)
 
-@pytest.mark.xfail(strict=True) # FIXME
 def test_bitarray():
   """run the bitarray unit tests"""