gnu: Add libgit2-1.7.

* gnu/packages/version-control.scm (libgit2-1.7): New variable.

Change-Id: I872208575dace0868dc7a2acd35c08f43871030e

gnu/packages/version-control.scm

@@ -886,6 +886,33 @@ write native speed custom Git applications in any language with bindings.")
     ;; GPLv2 with linking exception
     (license license:gpl2)))
 
+(define-public libgit2-1.7
+  (package
+    (inherit libgit2)
+    (version "1.7.1")
+    (source (origin
+              (inherit (package-source libgit2))
+              (method git-fetch)
+              (uri (git-reference
+                    (url "https://github.com/libgit2/libgit2")
+                    (commit (string-append "v" version))))
+              (file-name (git-file-name "libgit2" version))
+              (sha256
+               (base32
+                "1wq6a91k97gbsyafla39yvn1lnr559hqc41ksz1qxv7flf5kyvfx"))
+              ;; We need to use the bundled xdiff until an option is given
+              ;; to use the one from git.
+              (modules '((guix build utils)))
+              (snippet
+               '(begin
+                  (for-each delete-file-recursively
+                            '("deps/chromium-zlib"
+                              "deps/http-parser"
+                              "deps/ntlmclient"
+                              "deps/pcre"
+                              "deps/winhttp"
+                              "deps/zlib"))))))))
+
 (define-public libgit2-1.6
   (package
     (inherit libgit2)