139/197: installer: Allow file system specifications to be removed.

[Danny Milosavljevic]

dannym pushed a commit to branch wip-installer-2
in repository guix.

commit a6bbba8d89f70a48f02dc02b78ccb22acc5a7b60
Author: John Darrington <address@hidden>
Date:   Tue Jan 24 17:01:41 2017 +0100

    installer:  Allow file system specifications to be removed.
    
    * gnu/system/installer/mount-point.scm (mount-point-page-key-handler): Call
    assoc-remove! on entries which are #f
---
 gnu/system/installer/mount-point.scm | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/gnu/system/installer/mount-point.scm 
b/gnu/system/installer/mount-point.scm
index 794ec9f..b4b83aa 100644
--- a/gnu/system/installer/mount-point.scm
+++ b/gnu/system/installer/mount-point.scm
@@ -60,10 +60,11 @@
               (form-get-value form 'mount-point)
               (form-get-value form 'label)
               (form-get-value form 'fs-type))))
-        (when fss
-              (set! mount-points
-                    (assoc-set! mount-points dev fss))))
-      (page-leave))
+        (set! mount-points
+              (if fss
+                  (assoc-set! mount-points dev fss)
+                  (assoc-remove! mount-points dev)))
+        (page-leave)))
 
      ((buttons-key-matches-symbol? nav ch 'cancel)
       ;; Close the menu and return