gpgscm: Capture output of spawned processes.

* tests/gpgscm/tests.scm (call-check): Capture stdout and stderr, and
return stdout if the child exited successfully, or include stderr in
the error.
* tests/openpgp/version.scm: Demonstrate this by checking the stdout.

Signed-off-by: Justus Winter <justus@g10code.com>

tests/gpgscm/tests.scm

@@ -94,9 +94,6 @@
 		 CLOSED_FD
 		 (if (< *verbose* 0) STDOUT_FILENO CLOSED_FD)
 		 (if (< *verbose* 0) STDERR_FILENO CLOSED_FD)))
-(define (call-check what)
-  (if (not (= 0 (call what)))
-      (throw (list what "failed"))))
 
 ;; Accessor functions for the results of 'spawn-process'.
 (define :stdin car)
@@ -119,6 +116,12 @@
 ;; ':stderr' can also be used.
 (define :retcode car)
 
+(define (call-check what)
+  (let ((result (call-with-io what "")))
+    (if (= 0 (:retcode result))
+	(:stdout result)
+	(throw (list what "failed:" (:stderr result))))))
+
 (define (call-popen command input-string)
   (let ((result (call-with-io command input-string)))
     (if (= 0 (:retcode result))

tests/openpgp/version.scm

@@ -20,6 +20,5 @@
 (load (with-path "defs.scm"))
 
 (info "Printing the GPG version")
-(assert (= 0 (call `(,@GPG --version))))
-
-;; fixme: check that the output is as expected
+(assert (string-contains? (call-check `(,@GPG --version))
+			  "gpg (GnuPG) 2."))