Merge bitcoin/bitcoin#27928: test: Add more tests for the BIP21 implementation

f1d807e Add more tests for the BIP21 implementation (Kiminuo)

Pull request description:

  This PR is an attempt to make it clear how the current BIP21 implementation behaves in Bitcoin Core. Especially, I'm interested whether one can specify multiple `amount` (`message`, etc.) parameters.

  My primary end goal is to answer [this question of mine](https://bitcoin.stackexchange.com/questions/118654/how-to-interpret-bip21-uri-with-amount-specified-twice/) but I figured that maybe it's worth a PR. If not, I'll close the PR.

ACKs for top commit:
  MarcoFalke:
    lgtm ACK f1d807e
  kevkevinpal:
    ACK [f1d807e](bitcoin/bitcoin@f1d807e)

Tree-SHA512: d287809d47c5cfc667f850927bfd969bd345a996d3d53a4c26ef0ffd29eb75ef53358692a15f9a0493ec9e1c101123b6584572e25f87bcb98ff67f6b6c166de4

Author: ryanofsky

src/qt/test/uritests.cpp

@@ -58,9 +58,35 @@ void URITests::uriTests()
     uri.setUrl(QString("bitcoin:175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W?req-message=Wikipedia Example Address"));
     QVERIFY(GUIUtil::parseBitcoinURI(uri, &rv));
 
+    // Commas in amounts are not allowed.
     uri.setUrl(QString("bitcoin:175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W?amount=1,000&label=Wikipedia Example"));
     QVERIFY(!GUIUtil::parseBitcoinURI(uri, &rv));
 
     uri.setUrl(QString("bitcoin:175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W?amount=1,000.0&label=Wikipedia Example"));
     QVERIFY(!GUIUtil::parseBitcoinURI(uri, &rv));
+
+    // There are two amount specifications. The last value wins.
+    uri.setUrl(QString("bitcoin:175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W?amount=100&amount=200&label=Wikipedia Example"));
+    QVERIFY(GUIUtil::parseBitcoinURI(uri, &rv));
+    QVERIFY(rv.address == QString("175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W"));
+    QVERIFY(rv.amount == 20000000000LL);
+    QVERIFY(rv.label == QString("Wikipedia Example"));
+
+    // The first amount value is correct. However, the second amount value is not valid. Hence, the URI is not valid.
+    uri.setUrl(QString("bitcoin:175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W?amount=100&amount=1,000&label=Wikipedia Example"));
+    QVERIFY(!GUIUtil::parseBitcoinURI(uri, &rv));
+
+    // Test label containing a question mark ('?').
+    uri.setUrl(QString("bitcoin:175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W?amount=100&label=?"));
+    QVERIFY(GUIUtil::parseBitcoinURI(uri, &rv));
+    QVERIFY(rv.address == QString("175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W"));
+    QVERIFY(rv.amount == 10000000000LL);
+    QVERIFY(rv.label == QString("?"));
+
+    // Escape sequences are not supported.
+    uri.setUrl(QString("bitcoin:175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W?amount=100&label=%3F"));
+    QVERIFY(GUIUtil::parseBitcoinURI(uri, &rv));
+    QVERIFY(rv.address == QString("175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W"));
+    QVERIFY(rv.amount == 10000000000LL);
+    QVERIFY(rv.label == QString("%3F"));
 }