device: Clear storage before enrolling the first print

Clear the device storage before we enroll the first print. At that
point, we know that the storage should be completely empty and we have
no way of deleting "garbage" prints later if the device does not support
listing prints.

src/device.c

@@ -1797,8 +1797,9 @@ enroll_cb (FpDevice *dev, GAsyncResult *res, void *user_data)
    * enough. */
   if (g_error_matches (error, FP_DEVICE_ERROR, FP_DEVICE_ERROR_DATA_FULL))
     {
-      g_debug ("Device storage is full, trying to garbage collect old prints");
+      g_debug ("Device storage is full");
-      if (try_delete_print (rdev))
+      if (fp_device_has_feature (priv->dev, FP_DEVICE_FEATURE_STORAGE_LIST) &&
+          try_delete_print (rdev))
         {
           /* Success? Then restart the operation */
           fp_device_enroll (priv->dev,
@@ -1939,6 +1940,15 @@ enroll_identify_cb (FpDevice *dev, GAsyncResult *res, void *user_data)
   enroll_start (rdev);
 }
 
+static gboolean
+is_first_enrollment (FprintDevice * rdev)
+{
+  g_autoptr(GPtrArray) host_prints = NULL;
+  host_prints = load_all_prints (rdev);
+
+  return host_prints->len == 0;
+}
+
 static gboolean
 fprint_device_enroll_start (FprintDBusDevice      *dbus_dev,
                             GDBusMethodInvocation *invocation,
@@ -1991,6 +2001,15 @@ fprint_device_enroll_start (FprintDBusDevice      *dbus_dev,
   priv->enroll_data = finger;
   priv->current_action = ACTION_ENROLL;
 
+  if (is_first_enrollment (rdev))
+    {
+      g_autoptr(GError) clear_err = NULL;
+
+      if (!fp_device_clear_storage_sync (priv->dev, NULL, &clear_err))
+        g_warning ("Failed to clear storage before first enrollment: %s",
+                   clear_err->message);
+    }
+
   if (fp_device_has_feature (priv->dev, FP_DEVICE_FEATURE_IDENTIFY))
     {
       g_autoptr(GPtrArray) all_prints = load_all_prints (rdev);

tests/fprintd.py

@@ -850,7 +850,7 @@ class FPrintdVirtualStorageDeviceBaseTest(FPrintdVirtualDeviceBaseTest):
         self.assertIn(command, ['INSERT', 'REMOVE', 'SCAN', 'ERROR', 'RETRY',
             'FINGER', 'UNPLUG', 'SLEEP', 'SET_ENROLL_STAGES', 'SET_SCAN_TYPE',
             'SET_CANCELLATION_ENABLED', 'LIST', 'IGNORED_COMMAND',
-            'SET_KEEP_ALIVE'])
+            'SET_KEEP_ALIVE', 'CONT'])
 
         with Connection(self.sockaddr) as con:
             res = self._send_command(con, command, *args)
@@ -935,6 +935,8 @@ class FPrintdVirtualStorageDeviceTests(FPrintdVirtualStorageDeviceBaseTest):
           'FP1-20201231-7-ABCDEFGH-testuser' : 'right-index-finger',
           'no-metadata-new' : 'left-middle-finger',
         }
+        # Explicitly fail initial cleanup (not needed, but faster)
+        self.send_command('ERROR', 0)
         for i, f in enrolled_prints.items():
             self.enroll_print(i, f)
 
@@ -973,6 +975,8 @@ class FPrintdVirtualStorageDeviceTests(FPrintdVirtualStorageDeviceBaseTest):
         self.device.Claim('(s)', 'testuser')
 
         self.assertEqual(self.get_stored_prints(), ['stored-print'])
+        # Explicitly fail initial cleanup (not needed, but faster)
+        self.send_command('ERROR', 0)
         self.device.EnrollStart('(s)', 'right-thumb')
         self.send_image('stored-print')  # During identify
         self.wait_for_result('enroll-stage-passed')
@@ -990,6 +994,8 @@ class FPrintdVirtualStorageDeviceTests(FPrintdVirtualStorageDeviceBaseTest):
         self.device.Claim('(s)', 'testuser')
 
         self.assertEqual(self.get_stored_prints(), ['stored-print'])
+        # Explicitly fail initial cleanup (not needed, but faster)
+        self.send_command('ERROR', 0)
         self.device.EnrollStart('(s)', 'right-thumb')
         self.send_image('stored-print')  # During identify
         self.send_error(FPrint.DeviceError.PROTO)  # During garbage collecting
@@ -3065,6 +3071,10 @@ class FPrintdUtilsTest(FPrintdVirtualStorageDeviceBaseTest):
         self.set_keep_alive(True)
         self.device.Release()
 
+        # Open and clear storage
+        self.send_command('CONT')
+        self.send_command('CONT')
+
         finger_name = self.get_finger_name(FPrint.Finger.LEFT_THUMB)
         enroll, out = self.util_start('enroll', [self.get_current_user(),
             '-f', finger_name])
@@ -3105,6 +3115,10 @@ class FPrintdUtilsTest(FPrintdVirtualStorageDeviceBaseTest):
         self.set_keep_alive(True)
         self.device.Release()
 
+        # Open and clear storage
+        self.send_command('CONT')
+        self.send_command('CONT')
+
         finger_name = self.get_finger_name(FPrint.Finger.LEFT_MIDDLE)
         enroll, out = self.util_start('enroll', [self.get_current_user(),
             '-f', finger_name])