pin: avoid changing PIN unnecessarily

src/apps/management/recovery_device.py

@@ -57,6 +57,8 @@ async def recovery_device(ctx, msg):
     # ask for pin repeatedly
     if msg.pin_protection:
         newpin = await request_pin_confirm(ctx, cancellable=False)
+    else:
+        newpin = ""
 
     # dry run
     if msg.dry_run:
@@ -72,7 +74,7 @@ async def recovery_device(ctx, msg):
             )
 
     # save into storage
-    if msg.pin_protection:
+    if newpin:
         config.change_pin(pin_to_int(""), pin_to_int(newpin))
     storage.set_u2f_counter(msg.u2f_counter)
     storage.load_settings(label=msg.label, use_passphrase=msg.passphrase_protection)

src/apps/management/reset_device.py

@@ -73,8 +73,9 @@ async def reset_device(ctx, msg):
             await show_wrong_entry(ctx)
 
     # write PIN into storage
-    if not config.change_pin(pin_to_int(""), pin_to_int(newpin)):
-        raise wire.ProcessError("Could not change PIN")
+    if newpin:
+        if not config.change_pin(pin_to_int(""), pin_to_int(newpin)):
+            raise wire.ProcessError("Could not change PIN")
 
     # write settings and mnemonic into storage
     storage.load_settings(label=msg.label, use_passphrase=msg.passphrase_protection)

vendor/trezor-storage

@@ -1 +1 @@
-Subproject commit 0e897f673a2150607bae553e21604b253352644e
+Subproject commit 511fc205b284605651348512c5c5c2c95a642fa1