Merge bitcoin/bitcoin#25253: test: add coverage for non-hex value to -minimumchainwork

ebfc308ea4 test: add coverage for non-hex value to -minimumchainwork (brunoerg)

Pull request description:

  This PR adds test coverage for the following init error:
  https://github.com/bitcoin/bitcoin/blob/b9ef5a10e2fa4609d048db57b99463305455ebe4/src/init.cpp#L917-L919

  Passing a non-hex value to -minimumchainwork should throw an initial error.

ACKs for top commit:
  laanwj:
    Code review ACK ebfc308ea4
  kristapsk:
    re-ACK ebfc308ea4

Tree-SHA512: c665903757ae3b8b2480df97bb888e60ba4387b009fcb8031041822e87a155a0e4950ebe79873c1034f0826504521d82b1fdfdb5e8378b227d14ca545b8d4e11

test/functional/feature_minchainwork.py

@@ -106,5 +106,13 @@ class MinimumChainWorkTest(BitcoinTestFramework):
         # not be exercising the logic we want!)
         assert_equal(self.nodes[2].getblockchaininfo()['initialblockdownload'], True)
 
+        self.log.info("Test -minimumchainwork with a non-hex value")
+        self.stop_node(0)
+        self.nodes[0].assert_start_raises_init_error(
+            ["-minimumchainwork=test"],
+            expected_msg='Error: Invalid non-hex (test) minimum chain work value specified',
+        )
+
+
 if __name__ == '__main__':
     MinimumChainWorkTest().main()