8b2f471 qa: Fix double-negative arg test (Hennadii Stepanov)

Pull request description:

  Commit 67518f7 tests do not catch that a pointer is returned instead of a value.

  This PR makes test to not accept trailing characters after 0.

  From [IRC](http://www.erisian.com.au/bitcoin-core-dev/log-2020-01-07.html#l-358):
  >  \<hebasto\> ryanofsky: hmm, why test/functional/feature_config_args.py passed on 67518f7 ?
  >  \<hebasto\> I see now: test is broken.
  >  \<ryanofsky\> test should be unaffected by that change, do you see a break somewhere?
  >  \<hebasto\> yes: "-connect=0x7fff50369968" != "-connect=0"
  > ...
  >  \<ryanofsky\> Oh I see how that would happen, it should not be a problem in the current PR.
  >  \<hebasto\> going to submit a pr to fix test
  >  \<ryanofsky\> in the commit you mentioned, value is a pointer to a string, and it was printing the pointer address instead of the string on: LogPrintf("Warning: parsed potentially confusing double-negative -%s=%s\n", key, value);
  >  \<hebasto\> correct
  >  \<ryanofsky\> oh I see, test could be fixed to more robust and not accept trailing characters after 0

ACKs for top commit:
  ryanofsky:
    Code review ACK 8b2f471. I don't know how you found this but it's a nice catch! This change should make the test more reliable.

Tree-SHA512: 454b3d4415771d353a2da766f6ae6e0bfae7bdf485aaa7bfdd323595282356eeaf3f40e556b39f753bc35f578cbe9684368887eef2d63c5d7f0d7d9fa971697a

8b2f471 qa: Fix double-negative arg test (Hennadii Stepanov)

Pull request description:

  Commit 67518f7 tests do not catch that a pointer is returned instead of a value.

  This PR makes test to not accept trailing characters after 0.

  From [IRC](http://www.erisian.com.au/bitcoin-core-dev/log-2020-01-07.html#l-358):
  >  \<hebasto\> ryanofsky: hmm, why test/functional/feature_config_args.py passed on 67518f7 ?
  >  \<hebasto\> I see now: test is broken.
  >  \<ryanofsky\> test should be unaffected by that change, do you see a break somewhere?
  >  \<hebasto\> yes: "-connect=0x7fff50369968" != "-connect=0"
  > ...
  >  \<ryanofsky\> Oh I see how that would happen, it should not be a problem in the current PR.
  >  \<hebasto\> going to submit a pr to fix test
  >  \<ryanofsky\> in the commit you mentioned, value is a pointer to a string, and it was printing the pointer address instead of the string on: LogPrintf("Warning: parsed potentially confusing double-negative -%s=%s\n", key, value);
  >  \<hebasto\> correct
  >  \<ryanofsky\> oh I see, test could be fixed to more robust and not accept trailing characters after 0

ACKs for top commit:
  ryanofsky:
    Code review ACK 8b2f471. I don't know how you found this but it's a nice catch! This change should make the test more reliable.

Tree-SHA512: 454b3d4415771d353a2da766f6ae6e0bfae7bdf485aaa7bfdd323595282356eeaf3f40e556b39f753bc35f578cbe9684368887eef2d63c5d7f0d7d9fa971697a

- doc: fix git add argument bitcoin#18513
- build: Fix libevent linking for bench_bitcoin binary bitcoin#18397
- script: fix SCRIPT_ERR_SIG_PUSHONLY error string bitcoin#18412
- doc: Comment fix merkle.cpp bitcoin#18379
- log: Fix UB with bench on genesis block bitcoin#15283
- test: Fix mining to an invalid target + ensure that a new block has the correct hash internally bitcoin#18350
- Fix missing header in sync.h bitcoin#18357
- refactor: Fix implicit value conversion in formatPingTime bitcoin#18260
- Fix .gitignore policy in build_msvc directory bitcoin#18108
- build: Fix behavior when ALLOW_HOST_PACKAGES unset bitcoin#18051
- test: Fix p2p_invalid_messages failing in Python 3.8 because of warning bitcoin#17931
- qa: Fix double-negative arg test bitcoin#17893
- build: Fix configure report about qr bitcoin#17547
- log: Fix log message for -par=1 bitcoin#17325
- bench: Fix negative values and zero for -evals flag bitcoin#17267
- depends: fix boost mac cross build with clang 9+ bitcoin#17231
- doc: Fix broken bitcoin-cli examples bitcoin#17119
- doc: fix Makefile target in benchmarking.md bitcoin#17081
- contrib: fix minor typos in makeseeds.py bitcoin#17042
- test: Fix Python Docstring to include all Args. bitcoin#17030
- doc: Fix some misspellings bitcoin#17351
- doc: Doxygen-friendly script/descriptor.h comments bitcoin#16947
- doc: Fix doxygen errors bitcoin#17945
- doc: Doxygen-friendly CuckooCache comments bitcoin#16986
- doc: Add to Doxygen documentation guidelines bitcoin#17873
- depends: Consistent use of package variable bitcoin#17928
- init: Replace URL_WEBSITE with PACKAGE_URL bitcoin#18503
- doc: Add missed copyright headers bitcoin#17691

8b2f471 qa: Fix double-negative arg test (Hennadii Stepanov)

Pull request description:

  Commit 67518f7 tests do not catch that a pointer is returned instead of a value.

  This PR makes test to not accept trailing characters after 0.

  From [IRC](http://www.erisian.com.au/bitcoin-core-dev/log-2020-01-07.html#l-358):
  >  \<hebasto\> ryanofsky: hmm, why test/functional/feature_config_args.py passed on 67518f7 ?
  >  \<hebasto\> I see now: test is broken.
  >  \<ryanofsky\> test should be unaffected by that change, do you see a break somewhere?
  >  \<hebasto\> yes: "-connect=0x7fff50369968" != "-connect=0"
  > ...
  >  \<ryanofsky\> Oh I see how that would happen, it should not be a problem in the current PR.
  >  \<hebasto\> going to submit a pr to fix test
  >  \<ryanofsky\> in the commit you mentioned, value is a pointer to a string, and it was printing the pointer address instead of the string on: LogPrintf("Warning: parsed potentially confusing double-negative -%s=%s\n", key, value);
  >  \<hebasto\> correct
  >  \<ryanofsky\> oh I see, test could be fixed to more robust and not accept trailing characters after 0

ACKs for top commit:
  ryanofsky:
    Code review ACK 8b2f471. I don't know how you found this but it's a nice catch! This change should make the test more reliable.

Tree-SHA512: 454b3d4415771d353a2da766f6ae6e0bfae7bdf485aaa7bfdd323595282356eeaf3f40e556b39f753bc35f578cbe9684368887eef2d63c5d7f0d7d9fa971697a

Summary:
The test is made more robust by not accept trailing characters after 0.
This change was made after the test failed to fail when a bug was introduced (pointer address used instead of the string in a LogPrintf call).

This is a backport of Core [[bitcoin/bitcoin#17893 | PR17893]]

Test Plan: `ninja && test/functional/test_runner.py feature_config_args.py`

Reviewers: #bitcoin_abc, majcosta

Reviewed By: #bitcoin_abc, majcosta

Differential Revision: https://reviews.bitcoinabc.org/D8424

8b2f471 qa: Fix double-negative arg test (Hennadii Stepanov)

Pull request description:

  Commit 67518f7 tests do not catch that a pointer is returned instead of a value.

  This PR makes test to not accept trailing characters after 0.

  From [IRC](http://www.erisian.com.au/bitcoin-core-dev/log-2020-01-07.html#l-358):
  >  \<hebasto\> ryanofsky: hmm, why test/functional/feature_config_args.py passed on 67518f7 ?
  >  \<hebasto\> I see now: test is broken.
  >  \<ryanofsky\> test should be unaffected by that change, do you see a break somewhere?
  >  \<hebasto\> yes: "-connect=0x7fff50369968" != "-connect=0"
  > ...
  >  \<ryanofsky\> Oh I see how that would happen, it should not be a problem in the current PR.
  >  \<hebasto\> going to submit a pr to fix test
  >  \<ryanofsky\> in the commit you mentioned, value is a pointer to a string, and it was printing the pointer address instead of the string on: LogPrintf("Warning: parsed potentially confusing double-negative -%s=%s\n", key, value);
  >  \<hebasto\> correct
  >  \<ryanofsky\> oh I see, test could be fixed to more robust and not accept trailing characters after 0

ACKs for top commit:
  ryanofsky:
    Code review ACK 8b2f471. I don't know how you found this but it's a nice catch! This change should make the test more reliable.

Tree-SHA512: 454b3d4415771d353a2da766f6ae6e0bfae7bdf485aaa7bfdd323595282356eeaf3f40e556b39f753bc35f578cbe9684368887eef2d63c5d7f0d7d9fa971697a

8b2f471 qa: Fix double-negative arg test (Hennadii Stepanov)

Pull request description:

  Commit 67518f7 tests do not catch that a pointer is returned instead of a value.

  This PR makes test to not accept trailing characters after 0.

  From [IRC](http://www.erisian.com.au/bitcoin-core-dev/log-2020-01-07.html#l-358):
  >  \<hebasto\> ryanofsky: hmm, why test/functional/feature_config_args.py passed on 67518f7 ?
  >  \<hebasto\> I see now: test is broken.
  >  \<ryanofsky\> test should be unaffected by that change, do you see a break somewhere?
  >  \<hebasto\> yes: "-connect=0x7fff50369968" != "-connect=0"
  > ...
  >  \<ryanofsky\> Oh I see how that would happen, it should not be a problem in the current PR.
  >  \<hebasto\> going to submit a pr to fix test
  >  \<ryanofsky\> in the commit you mentioned, value is a pointer to a string, and it was printing the pointer address instead of the string on: LogPrintf("Warning: parsed potentially confusing double-negative -%s=%s\n", key, value);
  >  \<hebasto\> correct
  >  \<ryanofsky\> oh I see, test could be fixed to more robust and not accept trailing characters after 0

ACKs for top commit:
  ryanofsky:
    Code review ACK 8b2f471. I don't know how you found this but it's a nice catch! This change should make the test more reliable.

Tree-SHA512: 454b3d4415771d353a2da766f6ae6e0bfae7bdf485aaa7bfdd323595282356eeaf3f40e556b39f753bc35f578cbe9684368887eef2d63c5d7f0d7d9fa971697a