packages: Add 'patches' and related fields to <origin>.

See <https://lists.gnu.org/archive/html/guix-devel/2013-09/msg00137.html>
for the rationale.

* guix/packages.scm (<origin>)[patches, patch-flags, patch-inputs,
  patch-guile]: New fields.
  (%standard-patch-inputs, default-guile, patch-and-repack): New
  procedures.
  (package-source-derivation): When 'patches' is non-empty, call
  'patch-and-repack'.
* guix/utils.scm (file-sans-extension): New procedure.

1 files changed, 8 insertions, 0 deletions

diff --git a/guix/utils.scm b/guix/utils.scm
index 733319a0b4..1f3c0c8ad6 100644
--- a/guix/utils.scm
+++ b/guix/utils.scm
@@ -63,6 +63,7 @@
             package-name->name+version
             string-tokenize*
             file-extension
+            file-sans-extension
             call-with-temporary-output-file
             fold2
             filtered-port))
@@ -352,6 +353,13 @@ introduce the version part."
   (let ((dot (string-rindex file #\.)))
     (and dot (substring file (+ 1 dot) (string-length file)))))
 
+(define (file-sans-extension file)
+  "Return the substring of FILE without its extension, if any."
+  (let ((dot (string-rindex file #\.)))
+    (if dot
+        (substring file 0 dot)
+        file)))
+
 (define (string-tokenize* string separator)
   "Return the list of substrings of STRING separated by SEPARATOR.  This is
 like `string-tokenize', but SEPARATOR is a string."