gnu: flatpak: Fix binary path when exporting application files.

* gnu/packages/package-management.scm (flatpak): Use FLATPAK_BINARY
environment variable instead of patch.
[native-search-paths]: Add FLATPAK_BINARY.
[source]<patches>: Remove "flatpak-fix-path.patch".
* gnu/packages/patches/flatpak-fix-path.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): De-register it.

Fixes: #438
Change-Id: I094234b1ecf9b2bba6d499a0eae4559231a2f199
Signed-off-by: Danny Milosavljevic <dannym@friendly-machines.com>

gnu/local.mk

@@ -1303,7 +1303,6 @@ dist_patch_DATA =						\
   %D%/packages/patches/firebird-riscv64-support-pt1.patch	\
   %D%/packages/patches/firebird-riscv64-support-pt2.patch	\
   %D%/packages/patches/flann-cmake-3.11.patch			\
-  %D%/packages/patches/flatpak-fix-path.patch			\
   %D%/packages/patches/flatpak-fix-fonts-icons.patch	\
   %D%/packages/patches/flatpak-fix-icon-validation.patch	\
   %D%/packages/patches/flatpak-unset-gdk-pixbuf-for-sandbox.patch	\

gnu/packages/package-management.scm

@@ -2096,7 +2096,6 @@ the boot loader configuration.")
         (base32 "0ajbz8ms4h5nyjr59hv9z8vaimj4f3p51v8idmy14qnbmmjwa2nb"))
        (patches
         (search-patches "flatpak-fix-fonts-icons.patch"
-                        "flatpak-fix-path.patch"
                         "flatpak-fix-icon-validation.patch"
                         "flatpak-unset-gdk-pixbuf-for-sandbox.patch"))))
     (build-system meson-build-system)
@@ -2214,6 +2213,13 @@ cp -r /tmp/locale/*/en_US.*")))
                              libarchive
                              libseccomp
                              libxau))
+    (native-search-paths
+     (list (search-path-specification
+            (variable "FLATPAK_BINARY")
+            (separator #f)
+            (files '("bin"))
+            (file-pattern "^flatpak$")
+            (file-type 'regular))))
     (home-page "https://flatpak.org")
     (synopsis "System for building, distributing, and running sandboxed desktop
 applications")

gnu/packages/patches/flatpak-fix-path.patch

@@ -1,29 +0,0 @@
-Flatpak writes files for installed applications with the full Flatpak (store) path. This patch makes it write just "flatpak", using Flatpak from PATH. This is similar to the NixOS [0] patch, updated for Flatpak 1.12.1
-
-[0] https://github.com/NixOS/nixpkgs/blob/bf4167861d0f864b0fc457778d54feb4a2675ea2/pkgs/development/libraries/flatpak/use-flatpak-from-path.patch
-
-diff --git a/common/flatpak-dir.c b/common/flatpak-dir.c
-index 80ff5e5f..0c111c31 100644
---- a/common/flatpak-dir.c
-+++ b/common/flatpak-dir.c
-@@ -7134,8 +7134,7 @@ export_desktop_file (const char         *app,
-         flatpak = FLATPAK_BINDIR "/flatpak";
-
-       g_string_append_printf (new_exec,
--                              "%s run --branch=%s --arch=%s",
--                              flatpak,
-+                              "flatpak run --branch=%s --arch=%s",
-                               escaped_branch,
-                               escaped_arch);
-
-@@ -8467,8 +8466,8 @@ flatpak_dir_deploy (FlatpakDir          *self,
-       if ((flatpak = g_getenv ("FLATPAK_BINARY")) == NULL)
-         flatpak = FLATPAK_BINDIR "/flatpak";
-
--      bin_data = g_strdup_printf ("#!/bin/sh\nexec %s run --branch=%s --arch=%s %s \"$@\"\n",
--                                  flatpak, escaped_branch, escaped_arch, escaped_app);
-+      bin_data = g_strdup_printf ("#!/bin/sh\nexec flatpak run --branch=%s --arch=%s %s \"$@\"\n",
-+                                  escaped_branch, escaped_arch, escaped_app);
-       if (!g_file_replace_contents (wrapper, bin_data, strlen (bin_data), NULL, FALSE,
-                                     G_FILE_CREATE_REPLACE_DESTINATION, NULL, cancellable, error))
-         return FALSE;