gnu: go-github-com-urfave-cli: Fix tests when building with Go 1.17.

* gnu/packages/patches/go-github-com-urfave-cli-fix-tests.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/golang.scm (go-github-com-urfave-cli)[origin]: Apply it.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu/local.mk

@@ -1184,6 +1184,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/gobject-introspection-cc.patch		\
   %D%/packages/patches/gobject-introspection-girepository.patch	\
   %D%/packages/patches/go-fix-script-tests.patch			\
+  %D%/packages/patches/go-github-com-urfave-cli-fix-tests.patch \
   %D%/packages/patches/go-skip-gc-test.patch			\
   %D%/packages/patches/gpm-glibc-2.26.patch			\
   %D%/packages/patches/gpodder-disable-updater.patch		\

gnu/packages/golang.scm

@@ -4976,7 +4976,8 @@ as conversion to and from @command{net.Addr}.")
        (file-name (git-file-name name version))
        (sha256
         (base32
-         "10mcnvi5qmn00vpyk6si8gjka7p654wr9hac4zc9w5h3ickhvbdc"))))
+         "10mcnvi5qmn00vpyk6si8gjka7p654wr9hac4zc9w5h3ickhvbdc"))
+       (patches (search-patches "go-github-com-urfave-cli-fix-tests.patch"))))
     (build-system go-build-system)
     (arguments
      '(#:import-path "github.com/urfave/cli"))

gnu/packages/patches/go-github-com-urfave-cli-fix-tests.patch

@@ -0,0 +1,28 @@
+Backported from upstream PR: https://github.com/urfave/cli/pull/1299
+---
+diff --git a/app_test.go b/app_test.go
+index 33024ff..6b3aaa3 100644
+--- a/app_test.go
++++ b/app_test.go
+@@ -513,18 +513,18 @@ func TestApp_RunAsSubcommandParseFlags(t *testing.T) {
+ func TestApp_RunAsSubCommandIncorrectUsage(t *testing.T) {
+ 	a := App{
+ 		Flags: []Flag{
+-			StringFlag{Name: "--foo"},
++			StringFlag{Name: "foo"},
+ 		},
+ 		Writer: bytes.NewBufferString(""),
+ 	}
+ 
+ 	set := flag.NewFlagSet("", flag.ContinueOnError)
+-	_ = set.Parse([]string{"", "---foo"})
++	_ = set.Parse([]string{"", "-bar"})
+ 	c := &Context{flagSet: set}
+ 
+ 	err := a.RunAsSubcommand(c)
+ 
+-	expect(t, err, errors.New("bad flag syntax: ---foo"))
++	expect(t, err.Error(), "flag provided but not defined: -bar")
+ }
+ 
+ func TestApp_CommandWithFlagBeforeTerminator(t *testing.T) {