gnu: libgit2: Update to 0.28.1.

* gnu/packages/patches/libgit2-oom-test.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Remove it.
* gnu/packages/version-control.scm (libgit2): Update to 0.28.1.
[source](patches): Remove 'libgit2-oom-test.patch'.

gnu/local.mk

@@ -972,7 +972,6 @@ dist_patch_DATA =						\
   %D%/packages/patches/libexif-CVE-2017-7544.patch		\
   %D%/packages/patches/libgcrypt-make-yat2m-reproducible.patch	\
   %D%/packages/patches/libgit2-mtime-0.patch			\
-  %D%/packages/patches/libgit2-oom-test.patch			\
   %D%/packages/patches/libgdata-fix-tests.patch			\
   %D%/packages/patches/libgdata-glib-duplicate-tests.patch	\
   %D%/packages/patches/libgnome-encoding.patch			\

gnu/packages/patches/libgit2-oom-test.patch

@@ -1,62 +0,0 @@
-Fix a test failure on 32-bit platforms as reported
-at <https://github.com/libgit2/libgit2/issues/4868>.
-
-From 415a8ae9c9b6ac18f0524b6af8e58408b426457d Mon Sep 17 00:00:00 2001
-From: Edward Thomson <ethomson@edwardthomson.com>
-Date: Thu, 13 Sep 2018 13:27:07 +0100
-Subject: [PATCH] tests: don't run buf::oom on 32-bit systems
-
-On a 32-bit Linux systems, the value large enough to make malloc
-guarantee a failure is also large enough that valgrind considers it
-"fishy".  Skip this test on those systems entirely.
----
- tests/buf/oom.c | 14 +++++++++-----
- 1 file changed, 9 insertions(+), 5 deletions(-)
-
-diff --git a/tests/buf/oom.c b/tests/buf/oom.c
-index 2741a8ddf2..ec3bad9979 100644
---- a/tests/buf/oom.c
-+++ b/tests/buf/oom.c
-@@ -11,12 +11,8 @@
-  */
- #if defined(GIT_ARCH_64) && defined(__linux__)
- # define TOOBIG 0x0fffffffffffffff
--#elif defined(__linux__)
--# define TOOBIG 0x0fffffff
- #elif defined(GIT_ARCH_64)
- # define TOOBIG 0xffffffffffffff00
--#else
--# define TOOBIG 0xffffff00
- #endif
- 
- /**
-@@ -25,13 +21,18 @@
-  * will fail.  And because the git_buf_grow() wrapper always
-  * sets mark_oom, the code in git_buf_try_grow() will free
-  * the internal buffer and set it to git_buf__oom.
-- * 
-+ *
-  * We initialized the internal buffer to (the static variable)
-  * git_buf__initbuf.  The purpose of this test is to make sure
-  * that we don't try to free the static buffer.
-+ *
-+ * Skip this test entirely on 32-bit platforms; a buffer large enough
-+ * to guarantee malloc failures is so large that valgrind considers
-+ * it likely to be an error.
-  */
- void test_buf_oom__grow(void)
- {
-+#ifdef GIT_ARCH_64
- 	git_buf buf = GIT_BUF_INIT;
- 
- 	git_buf_clear(&buf);
-@@ -40,6 +41,9 @@ void test_buf_oom__grow(void)
- 	cl_assert(git_buf_oom(&buf));
- 
- 	git_buf_free(&buf);
-+#else
-+    cl_skip();
-+#endif
- }
- 
- void test_buf_oom__grow_by(void)

gnu/packages/version-control.scm

@@ -526,7 +526,7 @@ everything from small to very large projects with speed and efficiency.")
 (define-public libgit2
   (package
     (name "libgit2")
-    (version "0.27.7")
+    (version "0.28.1")
     (source (origin
               (method url-fetch)
               (uri (string-append "https://github.com/libgit2/libgit2/"
@@ -534,9 +534,8 @@ everything from small to very large projects with speed and efficiency.")
               (file-name (string-append name "-" version ".tar.gz"))
               (sha256
                (base32
-                "0c95pbv7hwclwmn51nqnh1lb0cajpcdb24pbdzcir6vmhfj3am0s"))
-              (patches (search-patches "libgit2-mtime-0.patch"
-                                       "libgit2-oom-test.patch"))
+                "0swk2dyq5a4p1jn5wvbcsrxckhh808vifxz5y8w663avg541188c"))
+              (patches (search-patches "libgit2-mtime-0.patch"))
 
               ;; Remove bundled software.
               (snippet '(begin