NewScriptPubkey: fix panic on empty scriptPubKey

If scriptPubKey is empty, we can't get &scriptPubKey[0] from it.

Author: starius

kernel/script_pubkey.go

@@ -35,7 +35,11 @@ func newScriptPubkey(ptr *C.btck_ScriptPubkey, fromOwned bool) *ScriptPubkey {
 // Parameters:
 //   - rawScriptPubkey: Serialized script pubkey data
 func NewScriptPubkey(rawScriptPubkey []byte) *ScriptPubkey {
-	ptr := C.btck_script_pubkey_create(unsafe.Pointer(&rawScriptPubkey[0]), C.size_t(len(rawScriptPubkey)))
+	var buf unsafe.Pointer
+	if len(rawScriptPubkey) > 0 {
+		buf = unsafe.Pointer(&rawScriptPubkey[0])
+	}
+	ptr := C.btck_script_pubkey_create(buf, C.size_t(len(rawScriptPubkey)))
 	return newScriptPubkey(check(ptr), true)
 }
 

kernel/script_pubkey_test.go

@@ -173,6 +173,16 @@ func TestInvalidScripts(t *testing.T) {
 			inputIndex:      0,
 			description:     "a random segwit transaction from the blockchain using native segwit - WITH WRONG SEGWIT",
 		},
+		{
+			name:            "empty_scriptpubkey",
+			scriptPubkeyHex: "",
+			amount:          0,
+			// Minimal coinbase-style transaction with a single empty scriptSig and zero-value output;
+			// used to trigger verification paths.
+			txToHex:     "01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff00ffffffff0100000000000000000000000000",
+			inputIndex:  0,
+			description: "empty scriptPubkey should fail verification",
+		},
 	}
 
 	for _, tt := range tests {