feat: Add Contact::get_or_gen_color. Use it in CFFI and JSON-RPC to avoid gray self-color (#7374)

`Contact::get_color()` returns gray if own keypair doesn't exist yet and we don't want any UIs
displaying it. Keypair generation can't be done in `get_color()` or `get_by_id_optional()` to avoid
breaking Core tests on key import. Also this makes the API clearer, pure getters shouldn't modify
any visible state.

src/contact.rs

@@ -1573,11 +1573,24 @@ impl Contact {
     }
 
     /// Returns a color for the contact.
-    /// See [`self::get_color`].
+    /// For self-contact this returns gray if own keypair doesn't exist yet.
+    /// See also [`self::get_color`].
     pub fn get_color(&self) -> u32 {
         get_color(self.id == ContactId::SELF, &self.addr, &self.fingerprint())
     }
 
+    /// Returns a color for the contact.
+    /// Ensures that the color isn't gray. For self-contact this generates own keypair if it doesn't
+    /// exist yet.
+    /// See also [`self::get_color`].
+    pub async fn get_or_gen_color(&self, context: &Context) -> Result<u32> {
+        let mut fpr = self.fingerprint();
+        if fpr.is_none() && self.id == ContactId::SELF {
+            fpr = Some(load_self_public_key(context).await?.dc_fingerprint());
+        }
+        Ok(get_color(self.id == ContactId::SELF, &self.addr, &fpr))
+    }
+
     /// Gets the contact's status.
     ///
     /// Status is the last signature received in a message from this contact.

src/contact/contact_tests.rs

@@ -4,7 +4,6 @@ use super::*;
 use crate::chat::{Chat, get_chat_contacts, send_text_msg};
 use crate::chatlist::Chatlist;
 use crate::receive_imf::receive_imf;
-use crate::securejoin::get_securejoin_qr;
 use crate::test_utils::{self, TestContext, TestContextManager, TimeShiftFalsePositiveNote};
 
 #[test]
@@ -775,16 +774,21 @@ async fn test_contact_get_color() -> Result<()> {
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-async fn test_self_color_vs_key() -> Result<()> {
+async fn test_self_color() -> Result<()> {
     let mut tcm = TestContextManager::new();
     let t = &tcm.unconfigured().await;
     t.configure_addr("alice@example.org").await;
     assert!(t.is_configured().await?);
-    let color = Contact::get_by_id(t, ContactId::SELF).await?.get_color();
+    let self_contact = Contact::get_by_id(t, ContactId::SELF).await?;
+    let color = self_contact.get_color();
     assert_eq!(color, 0x808080);
-    get_securejoin_qr(t, None).await?;
-    let color1 = Contact::get_by_id(t, ContactId::SELF).await?.get_color();
-    assert_ne!(color1, color);
+    let color = self_contact.get_or_gen_color(t).await?;
+    assert_ne!(color, 0x808080);
+    let color1 = self_contact.get_or_gen_color(t).await?;
+    assert_eq!(color1, color);
+
+    let bob = &tcm.bob().await;
+    assert_eq!(bob.add_or_lookup_contact(t).await.get_color(), color);
     Ok(())
 }