Improve error handling opening the cert store.

- Improvements similar to the one in the previous commit.

  - See #492.

src/commands/network.rs

@@ -927,6 +927,8 @@ pub fn dispatch_search(mut sq: Sq, c: cli::network::search::Command)
     let rt = tokio::runtime::Runtime::new()?;
     rt.block_on(async {
       for _ in 0..iterations {
+        let cert_store = sq.cert_store()?;
+
         let mut requests = JoinSet::new();
         let mut converged = true;
         std::mem::take(&mut queries).into_iter().for_each(|query| {
@@ -1024,7 +1026,7 @@ pub fn dispatch_search(mut sq: Sq, c: cli::network::search::Command)
             // Finally, we also consult the certificate store to
             // discover more identifiers.  This is sync, but we use
             // the same mechanism to merge the result back in.
-            if let Ok(Some(store)) = sq.cert_store() {
+            if let Some(store) = &cert_store {
                 pb.inc_length(1);
                 let mut email_query = UserIDQueryParams::new();
                 email_query.set_email(true);

src/commands/verify.rs

@@ -181,7 +181,7 @@ impl<'c, 'store, 'rstore> VHelper<'c, 'store, 'rstore> {
         }
     }
 
-    fn print_sigs(&mut self, results: &[VerificationResult]) {
+    fn print_sigs(&mut self, results: &[VerificationResult]) -> Result<()> {
         make_qprintln!(self.quiet);
         use crate::common::pki::output::print_path;
         use crate::print_error_chain;
@@ -265,7 +265,7 @@ impl<'c, 'store, 'rstore> VHelper<'c, 'store, 'rstore> {
                 qprintln!("Authenticating {} ({:?}) using the web of trust:",
                           cert_fpr, signer_userid);
 
-                if let Ok(Some(cert_store)) = self.sq.cert_store() {
+                if let Some(cert_store) = self.sq.cert_store()? {
                     // Build the network.
                     let cert_store = sequoia_wot::store::CertStore::from_store(
                         cert_store, self.sq.policy, reference_time);
@@ -432,6 +432,8 @@ impl<'c, 'store, 'rstore> VHelper<'c, 'store, 'rstore> {
 
             qprintln!("");
         }
+
+        Ok(())
     }
 }
 
@@ -514,8 +516,9 @@ impl<'c, 'store, 'rstore> VerificationHelper for VHelper<'c, 'store, 'rstore>
                         qprintln!("Encrypted using {}", sym_algo);
                     }
                 },
-                MessageLayer::SignatureGroup { ref results } =>
+                MessageLayer::SignatureGroup { ref results } => {
-                    self.print_sigs(results),
+                    self.print_sigs(results)?;
+                },
             }
         }
 

src/sq.rs

@@ -456,18 +456,18 @@ impl<'store: 'rstore, 'rstore> Sq<'store, 'rstore> {
 
     /// Returns the secret keys found in any specified keyrings.
     pub fn keyring_tsks(&self)
-        -> &BTreeMap<Fingerprint,
+        -> Result<&BTreeMap<Fingerprint,
-                     (Fingerprint, Key<key::PublicParts, key::UnspecifiedRole>)>
+                            (Fingerprint, Key<key::PublicParts, key::UnspecifiedRole>)>>
     {
         if let Some(keyring_tsks) = self.keyring_tsks.get() {
-            keyring_tsks
+            Ok(keyring_tsks)
         } else {
             // This also initializes keyring_tsks.
-            let _ = self.cert_store();
+            self.cert_store()?;
 
             // If something went wrong, we just set it to an empty
             // map.
-            self.keyring_tsks.get_or_init(|| BTreeMap::new())
+            Ok(self.keyring_tsks.get_or_init(|| BTreeMap::new()))
         }
     }
 
@@ -1293,7 +1293,7 @@ impl<'store: 'rstore, 'rstore> Sq<'store, 'rstore> {
         let try_keyrings = |cert: &Cert, key: &Key<_, _>|
             -> Result<_>
         {
-            let keyring_tsks = self.keyring_tsks();
+            let keyring_tsks = self.keyring_tsks()?;
             if let Some((cert_fpr, key))
                 = keyring_tsks.get(&key.fingerprint())
             {
@@ -1353,7 +1353,7 @@ impl<'store: 'rstore, 'rstore> Sq<'store, 'rstore> {
         let try_keyrings = |cert: &Cert, key: &Key<_, _>|
             -> Result<_>
         {
-            let keyring_tsks = self.keyring_tsks();
+            let keyring_tsks = self.keyring_tsks()?;
             if let Some((cert_fpr, key))
                 = keyring_tsks.get(&key.fingerprint())
             {