Fix #822 (#825)

Author: ben-kaufman

src/cryptoadvance/specter/server_endpoints/devices.py

@@ -258,7 +258,7 @@ def device(device_alias):
         action = request.form["action"]
         if action == "forget":
             if len(wallets) != 0:
-                err = "Device could not be removed since it is used in wallets: {}.\nYou must delete those wallets before you can remove this device.".format(
+                err = "Device could not be removed since it is used in wallets: {}.<br>You must delete those wallets before you can remove this device.<br>You can delete a wallet from its Settings -> Advanced page.".format(
                     [wallet.name for wallet in wallets]
                 )
             else:
@@ -270,8 +270,14 @@ def device(device_alias):
                 )
                 return redirect("")
         elif action == "delete_key":
-            key = request.form["key"]
-            device.remove_key(Key.from_json({"original": key}))
+            key = Key.from_json({"original": request.form["key"]})
+            wallets_with_key = [w for w in wallets if key in w.keys]
+            if len(wallets_with_key) != 0:
+                err = "Key could not be removed since it is used in wallets: {}.<br>You must delete those wallets before you can remove this key.<br>You can delete a wallet from its Settings -> Advanced page.".format(
+                    ", ".join([wallet.name for wallet in wallets_with_key])
+                )
+            else:
+                device.remove_key(key)
         elif action == "rename":
             device_name = request.form["newtitle"]
             if not device_name:

src/cryptoadvance/specter/templates/device/device.jinja

@@ -78,6 +78,7 @@
 		<br>
 		{% if device.supports_hwi_toggle_passphrase %}
 			<button type="button" class="btn centered" onclick="togglePassphrase('{{ device.device_type }}')">Toggle device passphrase</button>
+			<br>
 		{% endif %}
 		<form action="./" method="POST">
 			<button type="submit" name="action" value="forget" class="btn danger centered" id="forget_device">Forget the device</button>

src/cryptoadvance/specter/wallet.py

@@ -848,7 +848,11 @@ def get_electrum_file(self):
 
         to_return = {"wallet_type": "{}of{}".format(self.sigs_required, len(self.keys))}
         for cnt, device in enumerate(self.devices):
-            key = [key for key in device.keys if key in self.keys][0]
+            keys_matched = [key for key in device.keys if key in self.keys]
+            if keys_matched:
+                key = keys_matched[0]
+            else:
+                return {"error": "Missing key couldn't be found in any device"}
             if device.device_type in electrum_devices:
                 to_return["x{}/".format(cnt + 1)] = {
                     "ckcc_xfp": int(