tests: Normalize underlines.

  - GnuPG emits a header with underlines in key listings that changes
    with the length of GNUPGHOME.  Now, since the state directories
    are created within TMPDIR, the length of both GNUPGHOME and the
    underline changes.  Previously, we normalized GNUPGHOME, but we
    failed to normalize the underline.

  - Fixes #8.

tests/gpg.rs

@@ -243,12 +243,24 @@ impl Output {
     }
 
     /// Canonicalizes the paths in the output.
+    ///
+    /// This replaces `homedir` with `"/HOMEDIR"` and `experiment`
+    /// with `"/EXPERIMENT"` in stdout and stderr, and normalizes the
+    /// underline decorating `homedir` in key listings in stdout.
     fn canonicalize(mut self, homedir: &Path, experiment: &Path) -> Self {
+        const DASHES: &str =
+            "\n------------------------------------------------------------";
+        let d = regex::bytes::Regex::new(
+            &DASHES[..DASHES.len().min(homedir.to_str().unwrap().len() + 1)])
+            .unwrap();
         let h = regex::bytes::Regex::new(homedir.to_str().unwrap()).unwrap();
         let e = regex::bytes::Regex::new(experiment.to_str().unwrap()).unwrap();
         self.stdout =
-            e.replace_all(&h.replace_all(&self.stdout, &b"/HOMEDIR"[..]),
-                          &b"/EXPERIMENT"[..])
+            e.replace_all(
+                &h.replace_all(
+                    &d.replace_all(&self.stdout, &b"\n--------"[..]),
+                    &b"/HOMEDIR"[..]),
+                &b"/EXPERIMENT"[..])
             .into();
         self.stderr =
             e.replace_all(&h.replace_all(&self.stderr, &b"/HOMEDIR"[..]),