tests: Add macro managing ephemeral home directories.

* tests/openpgp/defs.scm (with-ephemeral-home-directory): New macro.
* tests/openpgp/setup.scm: Use the new macro.

tests/openpgp/defs.scm

@@ -200,6 +200,17 @@
 ;; GnuPG helper.
 ;;
 
+;; Evaluate a sequence of expressions with an ephemeral home
+;; directory.
+(macro (with-ephemeral-home-directory form)
+  `(let ((original-home-directory (getenv "GNUPGHOME")))
+     (with-temporary-working-directory
+      (define ephemeral-home-directory (getcwd))
+      (dynamic-wind
+	  (lambda () (setenv "GNUPGHOME" ephemeral-home-directory #t))
+	  (lambda () ,@(cdr form))
+	  (lambda () (setenv "GNUPGHOME" original-home-directory #t))))))
+
 ;; Call GPG to obtain the hash sums.  Either specify an input file in
 ;; ARGS, or an string in INPUT.  Returns a list of (<algo>
 ;; "<hashsum>") lists.

tests/openpgp/setup.scm

@@ -22,8 +22,7 @@
 (unless (member "--create-tarball" *args*)
 	(fail "Usage: setup.scm --create-tarball <file>"))
 
-(with-temporary-working-directory
- (setenv "GNUPGHOME" (getcwd) #t)
+(with-ephemeral-home-directory
  (create-gpghome)
  (create-legacy-gpghome)
  (stop-agent)