uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

pkgs/applications/office/libreoffice/darwin/update-utils.nix

@@ -0,0 +1,51 @@
+{ lib }:
+let
+  # extractLatestVersionFromHtml :: String -> String
+  extractLatestVersionFromHtml = htmlString:
+    let
+      majorMinorPatchGroup = "([0-9]+\\.[0-9]+\\.[0-9]+)";
+      splittedVersions = builtins.split "href=\"${majorMinorPatchGroup}" htmlString;
+      stableVersions = builtins.concatLists
+        (builtins.filter (e: builtins.isList e)
+          splittedVersions);
+    in
+    if stableVersions == [ ]
+    then abort "Failed to extract versions from html."
+    else lib.last (builtins.sort builtins.lessThan stableVersions);
+
+  # getHtml :: String -> String
+  getHtml = url:
+    builtins.readFile (builtins.fetchurl url);
+
+  # getLatestStableVersion :: String
+  getLatestStableVersion =
+    extractLatestVersionFromHtml
+      (getHtml "https://download.documentfoundation.org/libreoffice/stable/");
+
+  # extractSha256FromHtml :: String -> String
+  extractSha256FromHtml = htmlString:
+    let
+      sha256 = (builtins.match ".*([0-9a-fA-F]{64}).*" htmlString);
+    in
+    if sha256 == [ ]
+    then abort "Failed to extract sha256 from html."
+    else builtins.head sha256;
+
+  # getSha256 :: String -> String
+  getSha256 = dmgUrl: oldVersion: newVersion:
+    extractSha256FromHtml (getHtml (getSha256Url dmgUrl oldVersion newVersion));
+
+  # getSha256Url :: String -> String -> String -> String
+  getSha256Url = dmgUrl: oldVersion: newVersion:
+    (builtins.replaceStrings [ oldVersion ] [ newVersion ] dmgUrl) + ".sha256";
+
+in
+{
+  inherit
+    extractLatestVersionFromHtml
+    getHtml
+    getLatestStableVersion
+    extractSha256FromHtml
+    getSha256
+    getSha256Url;
+}