Merge #19014: test: Replace TEST_PREVIOUS_RELEASES env var with test_framework option

fad798be76dd5e330463c837fda768477d536078 test: Default --previous-releases to false if dir is empty (MarcoFalke)
faf1c3cc58d14f86ba5364e6ee5c8ef29cac2e26 test: Replace TEST_PREVIOUS_RELEASES env var with test_framework option (MarcoFalke)

Pull request description:

  The "auto-detection" feature is kept in place, but making it an option allows to properly document it. For example, on my machine I get:

  ```
  $ ./test/functional/wallet_disable.py --help | grep previous-releases
    --previous-releases   Force test of previous releases (default: False)

ACKs for top commit:
  Sjors:
    re-tACK fad798b

Tree-SHA512: a7377d0d5378be0a50be278d76396cc403583617b5fc43467773eee706df698acf3f4e67651491183b9b43a8e1816b052e4c17b90272b7ec4b6ac134ad811400

1 files changed, 10 insertions, 13 deletions

diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
index 6126efd842..716fa1d845 100755
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -140,6 +140,7 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
             sys.exit(exit_code)
 
     def parse_args(self):
+        previous_releases_path = os.getenv("PREVIOUS_RELEASES_DIR") or os.getcwd() + "/releases"
         parser = argparse.ArgumentParser(usage="%(prog)s [options]")
         parser.add_argument("--nocleanup", dest="nocleanup", default=False, action="store_true",
                             help="Leave bitcoinds and test.* datadir on exit or error")
@@ -154,6 +155,9 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
                             help="Print out all RPC calls as they are made")
         parser.add_argument("--portseed", dest="port_seed", default=os.getpid(), type=int,
                             help="The seed to use for assigning port numbers (default: current process id)")
+        parser.add_argument("--previous-releases", dest="prev_releases", action="store_true",
+                            default=os.path.isdir(previous_releases_path) and bool(os.listdir(previous_releases_path)),
+                            help="Force test of previous releases (default: %(default)s)")
         parser.add_argument("--coveragedir", dest="coveragedir",
                             help="Write tested RPC commands into this directory")
         parser.add_argument("--configfile", dest="configfile",
@@ -174,6 +178,7 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         parser.add_argument('--timeout-factor', dest="timeout_factor", type=float, default=1.0, help='adjust test timeouts by a factor. Setting it to 0 disables all timeouts')
         self.add_options(parser)
         self.options = parser.parse_args()
+        self.options.previous_releases_path = previous_releases_path
 
     def setup(self):
         """Call this method to start up the test framework object with options set."""
@@ -190,18 +195,16 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         fname_bitcoind = os.path.join(
             config["environment"]["BUILDDIR"],
             "src",
-            "bitcoind" + config["environment"]["EXEEXT"]
+            "bitcoind" + config["environment"]["EXEEXT"],
         )
         fname_bitcoincli = os.path.join(
             config["environment"]["BUILDDIR"],
             "src",
-            "bitcoin-cli" + config["environment"]["EXEEXT"]
+            "bitcoin-cli" + config["environment"]["EXEEXT"],
         )
         self.options.bitcoind = os.getenv("BITCOIND", default=fname_bitcoind)
         self.options.bitcoincli = os.getenv("BITCOINCLI", default=fname_bitcoincli)
 
-        self.options.previous_releases_path = os.getenv("PREVIOUS_RELEASES_DIR") or os.getcwd() + "/releases"
-
         os.environ['PATH'] = os.pathsep.join([
             os.path.join(config['environment']['BUILDDIR'], 'src'),
             os.path.join(config['environment']['BUILDDIR'], 'src', 'qt'), os.environ['PATH']
@@ -684,17 +687,11 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
 
     def has_previous_releases(self):
         """Checks whether previous releases are present and enabled."""
-        if os.getenv("TEST_PREVIOUS_RELEASES") == "false":
-            # disabled
-            return False
-
         if not os.path.isdir(self.options.previous_releases_path):
-            if os.getenv("TEST_PREVIOUS_RELEASES") == "true":
-                raise AssertionError("TEST_PREVIOUS_RELEASES=true but releases missing: {}".format(
+            if self.options.prev_releases:
+                raise AssertionError("Force test of previous releases but releases missing: {}".format(
                     self.options.previous_releases_path))
-            # missing
-            return False
-        return True
+        return self.options.prev_releases
 
     def is_cli_compiled(self):
         """Checks whether bitcoin-cli was compiled."""