openpgp: Wrap bare email addresses in angle brackets.

  - Change `UserID::from_address` to wrap a bare address in angle
    brackets.  That is, change `UserID::from_address` so that
    `UserID::from_address(None, None, "alice@example.org")` maps to
    `<alice@example.org>` not `alice@example.org`.  This has the
    advantage that the standard regular expression for scoping CAs can
    match bare email addresses, see:

    https://docs.sequoia-pgp.org/sequoia_openpgp/regex/index.html#caveat-emptor

  - Fixes #1076.

1 files changed, 6 insertions, 8 deletions

diff --git a/openpgp/src/packet/userid.rs b/openpgp/src/packet/userid.rs
index 4a1a6016..0b8b0ae6 100644
--- a/openpgp/src/packet/userid.rs
+++ b/openpgp/src/packet/userid.rs
@@ -657,14 +657,12 @@ impl UserID {
             }
         }
 
-        let something = !value.is_empty();
-        if something {
-            value.push_str(" <");
+        if !value.is_empty() {
+            value.push(' ');
         }
+        value.push('<');
         value.push_str(address);
-        if something {
-            value.push('>');
-        }
+        value.push('>');
 
         if check_address {
             // Make sure the combined thing is valid.
@@ -1315,7 +1313,7 @@ mod tests {
           Some("First Last"), Some("Comment"), Some("name@example.org"), None);
         c("First Last <name@example.org>",
           Some("First Last"), None, Some("name@example.org"), None);
-        c("name@example.org",
+        c("<name@example.org>",
           None, None, Some("name@example.org"), None);
     }
 
@@ -1411,7 +1409,7 @@ mod tests {
     fn from_address() {
         assert_eq!(UserID::from_address(None, None, "foo@bar.com")
                        .unwrap().value(),
-                   b"foo@bar.com");
+                   b"<foo@bar.com>");
         assert!(UserID::from_address(None, None, "foo@@bar.com").is_err());
         assert_eq!(UserID::from_address("Foo Q. Bar".into(), None, "foo@bar.com")
                       .unwrap().value(),