Auto merge of #6242 - sfackler:registry-username, r=alexcrichton

Allow usernames in alt registry URLs

We want to forbid secrets since they'll commonly end up checked into
source control, but usernames are fine (and are commonly going to be
`git`).

Closes #6241

r? @alexcrichton

src/cargo/util/config.rs

@@ -669,8 +669,8 @@ impl Config {
             match self.get_string(&format!("registries.{}.index", registry))? {
                 Some(index) => {
                     let url = index.val.to_url()?;
-                    if url.username() != "" || url.password().is_some() {
-                        bail!("Registry URLs may not contain credentials");
+                    if url.password().is_some() {
+                        bail!("Registry URLs may not contain passwords");
                     }
                     url
                 }

tests/testsuite/alt_registry.rs

@@ -458,7 +458,7 @@ fn publish_with_crates_io_dep() {
 }
 
 #[test]
-fn credentials_in_url_forbidden() {
+fn passwords_in_url_forbidden() {
     registry::init();
 
     let config = paths::home().join(".cargo/config");
@@ -489,6 +489,6 @@ fn credentials_in_url_forbidden() {
     p.cargo("publish --registry alternative -Zunstable-options")
         .masquerade_as_nightly_cargo()
         .with_status(101)
-        .with_stderr_contains("error: Registry URLs may not contain credentials")
+        .with_stderr_contains("error: Registry URLs may not contain passwords")
         .run();
 }