[core] Serialize reactivation and transmit requests. JB#51200

It didn't matter before, because reactivation was only happening during
initialization of ISO-DEP targets. The whole process was controlled by
nfcd, no external requests could be submitted until after the target
has been initialized, everything was nice and simple.

Now that we are considering exposing reactivation functionality over
D-Bus, we need to serialize reactivation and transmit requests and
that's a totally different game.

core/src/nfc_tag_t4.c

@@ -379,20 +379,30 @@ nfc_tag_t4_initialized(
     NfcTag* tag = &self->tag;
 
     GASSERT(!priv->init_id);
+    g_object_ref(self);
     nfc_target_sequence_unref(priv->init_seq);
     nfc_iso_dep_ndef_read_free(priv->init_read);
     priv->init_seq = NULL;
     priv->init_read = NULL;
     nfc_tag_set_initialized(tag);
+    g_object_unref(self);
 }
 
 static
 void
 nfc_tag_t4_init_done(
     NfcTarget* target,
-    void* user_data)
+    NFC_REACTIVATE_STATUS status,
+    void* self)
 {
-    nfc_tag_t4_initialized(NFC_TAG_T4(user_data));
+    /*
+     * It doesn't make sense to mark tag as initialized in case of
+     * reactivation timeout, because the tag going to get deactivated
+     * and dropped right after this function returns.
+     */
+    if (status != NFC_REACTIVATE_STATUS_TIMEOUT) {
+        nfc_tag_t4_initialized(NFC_TAG_T4(self));
+    }
 }
 
 static
@@ -407,10 +417,9 @@ nfc_tag_t4_ndef_read_done(
      * done now, to avoid blocking presence checks in case if reactivation
      * times out.
      */
-    nfc_target_sequence_unref(priv->init_seq);
-    priv->init_seq = NULL;
     GDEBUG("Reactivating Type 4 tag");
-    if (!nfc_target_reactivate(self->tag.target, nfc_tag_t4_init_done, self)) {
+    if (!nfc_target_reactivate(self->tag.target, priv->init_seq,
+        nfc_tag_t4_init_done, self)) {
         GDEBUG("Oops. Failed to reactivate, leaving the tag as is");
         nfc_tag_t4_initialized(self);
     }