Simplify the active_certification utility function.

- `active_certification` takes a fingerprint, and looks up the
    corresponding certificate in the certificate store.  But, all
    callers already have the certificate.  Avoid a lookup by taking a
    reference to the certificate.

src/commands.rs

@@ -3,7 +3,7 @@ use std::time::SystemTime;
 
 use sequoia_openpgp as openpgp;
 use openpgp::cert::prelude::*;
-use openpgp::{Cert, Fingerprint, KeyID, Result};
+use openpgp::{Cert, KeyID, Result};
 use openpgp::packet::prelude::*;
 use openpgp::parse::stream::*;
 use openpgp::policy::HashAlgoSecurity;
@@ -75,33 +75,15 @@ pub fn dispatch(sq: Sq, command: SqCommand) -> Result<()>
 
 /// Returns the active certification, if any, for the specified bindings.
 ///
-/// The certificate is looked up in the certificate store.
-///
 /// Note: if `n` User IDs are provided, then the returned vector has
 /// `n` elements.
-fn active_certification(sq: &Sq,
-                        cert: &Fingerprint, userids: Vec<UserID>,
-                        issuer: &Key<openpgp::packet::key::PublicParts,
-                                     openpgp::packet::key::UnspecifiedRole>)
+fn active_certification(
+    sq: &Sq,
+    cert: &Cert, userids: Vec<UserID>,
+    issuer: &Key<openpgp::packet::key::PublicParts,
+                 openpgp::packet::key::UnspecifiedRole>)
     -> Vec<(UserID, Option<Signature>)>
 {
-    // Look up the cert and find the certifications for the specified
-    // User ID, if any.
-    let lc = sq.cert_store_or_else()
-        .and_then(|cert_store| cert_store.lookup_by_cert_fpr(cert));
-    let lc = match lc {
-        Ok(lc) => lc,
-        Err(_) => {
-            return userids.into_iter().map(|userid| (userid, None)).collect();
-        }
-    };
-    let cert = match lc.to_cert() {
-        Ok(cert) => cert,
-        Err(_) => {
-            return userids.into_iter().map(|userid| (userid, None)).collect();
-        }
-    };
-
     let issuer_kh = issuer.key_handle();
 
     userids.into_iter().map(|userid| {

src/commands/network.rs

@@ -240,7 +240,7 @@ fn certify(sq: &Sq,
     }
 
     let certifications = active_certification(
-            sq, &cert.fingerprint(),
+            sq, cert,
             userids.iter().cloned().collect(),
             signer.public())
         .into_iter()

src/commands/pki/link.rs

@@ -485,7 +485,7 @@ pub fn add(sq: Sq, c: link::AddCommand)
         .context("Looking up local trust root")?;
 
     let certifications = active_certification(
-            &sq, &vc.fingerprint(), userids,
+            &sq, &cert, userids,
             signer.public())
         .into_iter()
         .map(|(userid, active_certification)| {
@@ -650,7 +650,7 @@ pub fn retract(sq: Sq, c: link::RetractCommand)
         .context("Looking up local trust root")?;
 
     let certifications = active_certification(
-            &sq, &cert.fingerprint(), userids, signer.public())
+            &sq, &cert, userids, signer.public())
         .into_iter()
         .map(|(userid, active_certification)| {
             let userid_str = || String::from_utf8_lossy(userid.value());
@@ -770,9 +770,19 @@ pub fn list(sq: Sq, c: link::ListCommand)
 
     let cert_store = sq.cert_store_or_else()?;
     for cert in cert_store.certs() {
+        let cert = if let Ok(cert) = cert.to_cert() {
+            cert
+        } else {
+            // Invalid cert.  Skip it.
+            continue;
+        };
+
+        let userids = cert.userids()
+            .map(|ua| ua.userid().clone())
+            .collect::<Vec<_>>();
+
         for (userid, certification) in active_certification(
-                &sq, &cert.fingerprint(), cert.userids().collect(),
-                trust_root_key)
+                &sq, &cert, userids, trust_root_key)
             .into_iter()
             .filter_map(|(user, certification)| {
                 if let Some(certification) = certification {