tests: Skip Python tests if the bindings are not built.

* tests/gpgme/wrap.scm (python): Move variable...
* tests/gpgme/gpgme-defs.scm (python): ... here.
(run-python-tests?): New function.
* tests/gpgme/run-tests.scm: Only run Python tests if the bindings can
be located in GPGME's build directory.

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

tests/gpgme/gpgme-defs.scm

@@ -171,3 +171,13 @@
 	    (else
 	     (expand-one (append acc (list (car v))) (cdr v))))))
 	values)))
+
+(define python (catch #f
+		      (path-expand "python" (string-split (getenv "PATH") *pathsep*))))
+(define (run-python-tests?)
+  (let* ((python-version
+	  (string-trim char-whitespace?
+		       (call-popen `(,python -c "import sys; print('{0}.{1}'.format(sys.version_info[0], sys.version_info[1]))") "")))
+	 (build-path (path-join gpgme-builddir "lang" "python"
+				(string-append "python" python-version "-gpg"))))
+    (trace (file-exists? (trace build-path)))))

tests/gpgme/run-tests.scm

@@ -71,5 +71,7 @@
 			     -- ,@(:path cmpnts))))
 		  (if (null? tests) (all-tests makefile (:key cmpnts)) tests))))
 	 `((("tests" "gpg") "c_tests" ,setup-c)
-	   (("lang" "python" "tests") "py_tests" ,setup-py)
+	   ,@(if (run-python-tests?)
+		 `((("lang" "python" "tests") "py_tests" ,setup-py))
+		 '())
 	   (("lang" "qt" "tests") "TESTS" ,setup-c))))))

tests/gpgme/wrap.scm

@@ -29,9 +29,6 @@
 (setenv "top_srcdir" gpgme-srcdir #t)
 (setenv "srcdir" (path-join gpgme-srcdir "tests" "gpg") #t)
 
-(define python (catch #f
-		      (path-expand "python" (string-split (getenv "PATH") *pathsep*))))
-
 (define (run what)
   (if (string-suffix? (car what) ".py")
       (begin