Bugfix in bn2vch: avoid excessive padding #18374

1. 
   sipa commented at 5:46 am on March 18, 2020: member

   It seems #17319 introduced an (unobserved) bug in the test framework in bn2vch: a zero padding byte was added for every nonzero number, even when the top byte was <= 0x7F. Fix this.
2. 
   sipa commented at 5:46 am on March 18, 2020: member

   I’m happy to add a quick test case for this, but I don’t see any obvious place to put a test of the test framework itself. Any suggestions?
3. fanquake added the label Tests on Mar 18, 2020
4. in test/functional/test_framework/script.py:36 in 812340c395 outdated

   32@@ -33,6 +33,7 @@ def bn2vch(v):
   33     ext = bytearray()
   34     if v.bit_length() > 0:
   35         have_ext = (v.bit_length() & 0x07) == 0
   36+    if have_ext:
   

   ---

   ---

   

   kallewoof commented at 6:00 am on March 18, 2020:

   Alternative

   0if v.bit_length() > 0 and (v.bit_length() & 0x07) == 0:
   1    have_ext = True
   2    ext.append(0)
   

   ---

   

   sipa commented at 7:20 am on March 18, 2020:

   Thanks, much better indeed.
5. Bugfix in bn2vch: avoid excessive padding f65868baa9
6. sipa force-pushed on Mar 18, 2020
7. 
   DrahtBot commented at 7:44 am on March 18, 2020: member

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Conflicts

   Reviewers, this pull request conflicts with the following ones:

   • #17977 ([WIP] Implement BIP 340-342 validation (Schnorr/taproot/tapscript) by sipa)

   If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

8. in test/functional/test_framework/script.py:34 in f65868baa9

   30@@ -31,8 +31,8 @@ def bn2vch(v):
   31     # isn't a spare bit in the bit length, add an extension byte.
   32     have_ext = False
   33     ext = bytearray()
   34-    if v.bit_length() > 0:
   35-        have_ext = (v.bit_length() & 0x07) == 0
   36+    if v.bit_length() > 0 && (v.bit_length() & 0x07) == 0:
   

   ---

   ---

   

   MarcoFalke commented at 1:47 pm on March 18, 2020:

   0    if v.bit_length() > 0 and (v.bit_length() & 0x07) == 0:
   

9. 
   sipa commented at 5:23 pm on March 18, 2020: member

   Closing in favor of #18378.
10. sipa closed this on Mar 18, 2020

    ---

11. laanwj referenced this in commit 67de1ee8bc on Mar 19, 2020
12. DrahtBot locked this on Feb 15, 2022

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sipa kallewoof DrahtBot MarcoFalke

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