test: Add device test for signing an empty message in Decred which uses the BLAKE hash function.

tests/device_tests/test_msg_signmessage.py

@@ -190,6 +190,16 @@ VECTORS = (  # case name, coin_name, path, script_type, address, message, signat
         "206b1f8ba47ef9eaf87aa900e41ab1e97f67e8c09292faa4acf825228d074c4b774484046dcb1d9bbf0603045dbfb328c3e1b0c09c5ae133e89e604a67a1fc6cca",
         altcoin=True,
     ),
+    case(
+        "decred-empty",
+        "Decred",
+        "44h/42h/0h/0/0",
+        S.SPENDADDRESS,
+        "DsZtHtXHwvNR3nWf1PqfxrEdnRJisKEyzp1",
+        "",
+        "1fd2d57490b44a0361c7809768cad032d41ba1d4b7a297f935fc65ae05f71de7ea0c6c6fd265cc5154f1fa4acd7006b6a00ddd67fb7333c1594aff9120b3ba8024",
+        altcoin=True,
+    ),
 )
 
 

tests/ui_tests/fixtures.json

@@ -385,6 +385,7 @@
 "test_msg_signmessage.py::test_signmessage[NFC message]": "69bd412ca0c2f980b7e0bfcc8329c7454b144d89bae40193ef8e61bdf24a6961",
 "test_msg_signmessage.py::test_signmessage[NFKD message]": "69bd412ca0c2f980b7e0bfcc8329c7454b144d89bae40193ef8e61bdf24a6961",
 "test_msg_signmessage.py::test_signmessage[bcash]": "d25510e01fb7599df0cd81fbc4b843fe08950435a0c706ced32682954fd66adc",
+"test_msg_signmessage.py::test_signmessage[decred-empty]": "a27757cfa7a25e46162d04429e2054a22891645b452952cf1762da166b4958d2",
 "test_msg_signmessage.py::test_signmessage[decred]": "8ba7d70f772524c74642fd13ddaf86e331cc8edea04ab550561cce58c89195ae",
 "test_msg_signmessage.py::test_signmessage[grs-p2pkh]": "ec3e945d48671cb2636eb0894f2f9e098021f4f887ed5811038786ecbe888f32",
 "test_msg_signmessage.py::test_signmessage[grs-segwit-native]": "ec3e945d48671cb2636eb0894f2f9e098021f4f887ed5811038786ecbe888f32",