openpgp: Fix Signature::get_issuer to return set of issuers.

  - A signature can contain multiple hints as to who created the
    signature.  Return all those hints to the caller.

  - Adapt all callers accordingly.

  - Fixes #264.

1 files changed, 3 insertions, 4 deletions

diff --git a/openpgp/examples/web-of-trust.rs b/openpgp/examples/web-of-trust.rs
index 754a7b13..34cbe289 100644
--- a/openpgp/examples/web-of-trust.rs
+++ b/openpgp/examples/web-of-trust.rs
@@ -10,6 +10,7 @@
 use std::env;
 
 extern crate sequoia_openpgp as openpgp;
+use crate::openpgp::KeyID;
 use crate::openpgp::tpk::TPKParser;
 use crate::openpgp::parse::Parse;
 
@@ -39,14 +40,12 @@ fn main() {
                     let keyid = tpk.keyid();
                     for uidb in tpk.userids() {
                         for tps in uidb.certifications() {
-                            if let Some(issuer) = tps.get_issuer() {
+                            for issuer in tps.get_issuers() {
                                 println!("{}, {:?}, {}",
-                                         issuer.as_u64().unwrap(),
+                                         KeyID::from(issuer).as_u64().unwrap(),
                                          String::from_utf8_lossy(
                                              uidb.userid().value()),
                                          keyid.as_u64().unwrap());
-                            } else {
-                                eprintln!("No issuer!?");
                             }
                         }
                     }