VCard color is different from contact color

[WofWca]

• Operating System (Linux/Mac/Windows/iOS/Android): All
• Core Version: v2.17.0
• Client Version: 2.15.0

Expected behavior

"Share contact" VCard color is the same as the eventual contact's color when you start a chat with that contact.

Actual behavior

The colors are different.

Steps to reproduce the problem

1. Share a contact that has no avatar in a chat.

Screenshots

The bug exists since 9af00af (#7134). The VCard color and contact color used to be the same, str_to_color(addr.to_lowercase()), but fell out of sync.

core/deltachat-jsonrpc/src/api/types/contact.rs

Line 133 in 7da8489

let color = color::str_to_color(&vc.addr.to_lowercase());

core/src/contact.rs

Lines 1577 to 1588 in af58b86

	/// Get a color for the contact.
	/// The color is calculated from the contact's fingerprint (for key-contacts)
	/// or email address (for address-contacts) and can be used
	/// for an fallback avatar with white initials
	/// as well as for headlines in bubbles of group chats.
	pub fn get_color(&self) -> u32 {
	if let Some(fingerprint) = self.fingerprint() {
	str_to_color(&fingerprint.hex())
	} else {
	str_to_color(&self.addr.to_lowercase())
	}
	}

It would have been easy to fix, but apparently VCard doesn't have the "fingerprint" property, only a key:

core/deltachat-contact-tools/src/vcard.rs

Lines 12 to 27 in 7ec7329

	/// A Contact, as represented in a VCard.
	pub struct VcardContact {
	/// The email address, vcard property `email`
	pub addr: String,
	/// This must be the name authorized by the contact itself, not a locally given name. Vcard
	/// property `fn`. Can be empty, one should use `display_name()` to obtain the display name.
	pub authname: String,
	/// The contact's public PGP key in Base64, vcard property `key`
	pub key: Option<String>,
	/// The contact's profile image (=avatar) in Base64, vcard property `photo`
	pub profile_image: Option<String>,
	/// The biography, stored in the vcard property `note`
	pub biography: Option<String>,
	/// The timestamp when the vcard was created / last updated, vcard property `rev`
	pub timestamp: Result<i64>,
	}

I'm not sure if it's worth recalculating the fingerprint every time, or maybe it's better to store it together with the key.

core/src/contact.rs

Lines 339 to 355 in af58b86

	let fingerprint;
	if let Some(public_key) = key {
	fingerprint = public_key.dc_fingerprint().hex();
	context
	.sql
	.execute(
	"INSERT INTO public_keys (fingerprint, public_key)
	VALUES (?, ?)
	ON CONFLICT (fingerprint)
	DO NOTHING",
	(&fingerprint, public_key.to_bytes()),
	)
	.await?;
	} else {
	fingerprint = String::new();
	}