gnu: sudo: Update to 1.9.4.

* gnu/packages/admin.scm (sudo): Update to 1.9.4.
[source]: Add patch.
* gnu/packages/patches/sudo-fix-build-without-sendmail.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.

gnu/local.mk

@@ -1443,6 +1443,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/sdl-pango-matrix_declarations.patch	\
   %D%/packages/patches/sdl-pango-sans-serif.patch		\
   %D%/packages/patches/sqlite-hurd.patch			\
+  %D%/packages/patches/sudo-fix-build-without-sendmail.patch	\
   %D%/packages/patches/sunxi-tools-remove-sys-io.patch	\
   %D%/packages/patches/patchutils-test-perms.patch		\
   %D%/packages/patches/patch-hurd-path-max.patch		\

gnu/packages/admin.scm

@@ -1397,7 +1397,7 @@ system administrator.")
 (define-public sudo
   (package
     (name "sudo")
-    (version "1.9.3p1")
+    (version "1.9.4")
     (source (origin
               (method url-fetch)
               (uri
@@ -1407,7 +1407,8 @@ system administrator.")
                                     version ".tar.gz")))
               (sha256
                (base32
-                "17mldsg5d08s23cskmjxfa81ibnqw3slgf3l4023j72ywi9xxffw"))
+                "1w03257akspgkkl757vmpq3p30sb2n6y61hll038mw9sqwnbv4cb"))
+              (patches (search-patches "sudo-fix-build-without-sendmail.patch"))
               (modules '((guix build utils)))
               (snippet
                '(begin

gnu/packages/patches/sudo-fix-build-without-sendmail.patch

@@ -0,0 +1,45 @@
+
+# HG changeset patch
+# User Todd C. Miller <Todd.Miller@sudo.ws>
+# Date 1606767492 25200
+# Node ID 41db1aad85bbce444b511bcb28b9628a0a22fcd9
+# Parent  96a5cfe3c66b6ee84d7f7b6fb26d932f45a44b76
+Fix build when configured using --without-sendmail
+Bug #947
+
+diff -r 96a5cfe3c66b -r 41db1aad85bb lib/eventlog/eventlog.c
+--- a/lib/eventlog/eventlog.c	Sun Nov 29 15:11:34 2020 -0700
++++ b/lib/eventlog/eventlog.c	Mon Nov 30 13:18:12 2020 -0700
+@@ -78,7 +78,7 @@
+ static FILE *eventlog_stub_open_log(int type, const char *logfile);
+ static void eventlog_stub_close_log(int type, FILE *fp);
+ 
+-/* Eventlog config settings */
++/* Eventlog config settings (default values). */
+ static struct eventlog_config evl_conf = {
+     EVLOG_NONE,			/* type */
+     EVLOG_SUDO,			/* format */
+@@ -91,7 +91,11 @@
+     false,			/* omit_hostname */
+     _PATH_SUDO_LOGFILE,		/* logpath */
+     "%h %e %T",			/* time_fmt */
++#ifdef _PATH_SUDO_SENDMAIL
+     _PATH_SUDO_SENDMAIL,	/* mailerpath */
++#else
++    NULL,			/* mailerpath (disabled) */
++#endif
+     "-t",			/* mailerflags */
+     NULL,			/* mailfrom */
+     MAILTO,			/* mailto */
+@@ -1436,8 +1440,10 @@
+ 	evl_conf.logpath = _PATH_SUDO_LOGFILE;
+     if (evl_conf.time_fmt == NULL)
+ 	evl_conf.time_fmt = "%h %e %T";
++#ifdef _PATH_SUDO_SENDMAIL
+     if (evl_conf.mailerpath == NULL)
+ 	evl_conf.mailerpath = _PATH_SUDO_SENDMAIL;
++#endif
+     if (evl_conf.mailerflags == NULL)
+ 	evl_conf.mailerflags = "-t";
+     if (evl_conf.mailto == NULL)
+