gnu: libgit2: Update to 0.26.0.

* gnu/packages/version-control.scm (libgit2): Update to 0.26.0.  Remove
"libgit2-use-after-free.patch".
* gnu/packages/patches/libgit2-use-after-free.patch: Remove.
* gnu/local.mk (dist_patch_DATA): Remove it.

gnu/local.mk

@@ -756,7 +756,6 @@ dist_patch_DATA =						\
   %D%/packages/patches/libgit2-0.25.1-mtime-0.patch		\
   %D%/packages/patches/libgdata-fix-tests.patch			\
   %D%/packages/patches/libgdata-glib-duplicate-tests.patch	\
-  %D%/packages/patches/libgit2-use-after-free.patch		\
   %D%/packages/patches/libjxr-fix-function-signature.patch	\
   %D%/packages/patches/libjxr-fix-typos.patch			\
   %D%/packages/patches/liboop-mips64-deplibs-fix.patch		\

gnu/packages/patches/libgit2-use-after-free.patch

@@ -1,24 +0,0 @@
-This patch is taken from <https://github.com/libgit2/libgit2/pull/4122>;
-we need it to fix the use-after-free error in 'git_commit_extract_signature'
-reported at <https://github.com/libgit2/libgit2/issues/4118>.
-
-From ade0d9c658fdfc68d8046935f6908f033fe7a529 Mon Sep 17 00:00:00 2001
-From: Patrick Steinhardt <ps@pks.im>
-Date: Mon, 13 Feb 2017 13:46:17 +0100
-Subject: [PATCH 3/3] commit: avoid possible use-after-free
-
-diff --git a/src/commit.c b/src/commit.c
-index 89a4db1..05b70a9 100644
---- a/src/commit.c
-+++ b/src/commit.c
-@@ -766,8 +766,9 @@ int git_commit_extract_signature(git_buf *signature, git_buf *signed_data, git_r
- 		if (git_buf_oom(signature))
- 			goto oom;
- 
-+		error = git_buf_puts(signed_data, eol+1);
- 		git_odb_object_free(obj);
--		return git_buf_puts(signed_data, eol+1);
-+		return error;
- 	}
- 
- 	giterr_set(GITERR_OBJECT, "this commit is not signed");

gnu/packages/version-control.scm

@@ -334,7 +334,7 @@ everything from small to very large projects with speed and efficiency.")
 (define-public libgit2
   (package
     (name "libgit2")
-    (version "0.25.1")
+    (version "0.26.0")
     (source (origin
               (method url-fetch)
               (uri (string-append "https://github.com/libgit2/libgit2/"
@@ -342,9 +342,8 @@ everything from small to very large projects with speed and efficiency.")
               (file-name (string-append name "-" version ".tar.gz"))
               (sha256
                (base32
-                "1cdwcw38frc1wf28x5ppddazv9hywc718j92f3xa3ybzzycyds3s"))
+                "1fdk9yhwvl1w1z71ykzcvgh4nsf8scxcbclz5anh98zpplmhmisa"))
-              (patches (search-patches "libgit2-use-after-free.patch"
+              (patches (search-patches "libgit2-0.25.1-mtime-0.patch"))))
-                                       "libgit2-0.25.1-mtime-0.patch"))))
     (build-system cmake-build-system)
     (arguments
      `(#:phases