[libgit2-glib] Fix diffing a blob to a buffer using GObject-Introspection

[Garrett Regier <gregier src gnome org>]

commit 1abb137fed2e7c3002b78e46c7c84a423ad92a52
Author: Garrett Regier <garrettregier gmail com>
Date:   Sat Aug 23 06:50:29 2014 -0700

    Fix diffing a blob to a buffer using GObject-Introspection
    
    Must use guint8 for a byte array not gchar, otherwise
    Python can't use the method at all. This is already done
    in various other places that provide the length.

 libgit2-glib/ggit-diff.c |   13 ++++++++++---
 libgit2-glib/ggit-diff.h |    4 ++--
 2 files changed, 12 insertions(+), 5 deletions(-)
---
diff --git a/libgit2-glib/ggit-diff.c b/libgit2-glib/ggit-diff.c
index 4ae9edf..d4889fc 100644
--- a/libgit2-glib/ggit-diff.c
+++ b/libgit2-glib/ggit-diff.c
@@ -18,6 +18,8 @@
  * along with libgit2-glib. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <string.h>
+
 #include <git2.h>
 
 #include "ggit-diff.h"
@@ -757,8 +759,8 @@ ggit_diff_blobs (GgitBlob              *old_blob,
 void
 ggit_diff_blob_to_buffer (GgitBlob              *old_blob,
                           const gchar           *old_as_path,
-                          const gchar           *buffer,
-                          gsize                  buffer_len,
+                          const guint8          *buffer,
+                          gssize                 buffer_len,
                           const gchar           *buffer_as_path,
                           GgitDiffOptions       *diff_options,
                           GgitDiffFileCallback   file_cb,
@@ -782,6 +784,11 @@ ggit_diff_blob_to_buffer (GgitBlob              *old_blob,
        wrapper_data.diff = NULL;
        wrapper_data.encoding = NULL;
 
+       if (buffer_len == -1)
+       {
+               buffer_len = strlen((const gchar *) buffer);
+       }
+
        if (file_cb != NULL)
        {
                real_file_cb = ggit_diff_file_callback_wrapper;
@@ -802,7 +809,7 @@ ggit_diff_blob_to_buffer (GgitBlob              *old_blob,
 
        ret = git_diff_blob_to_buffer (old_blob ? _ggit_native_get (old_blob) : NULL,
                                       old_as_path,
-                                      buffer,
+                                      (const gchar *) buffer,
                                       buffer_len,
                                       buffer_as_path,
                                       (git_diff_options *) gdiff_options,
diff --git a/libgit2-glib/ggit-diff.h b/libgit2-glib/ggit-diff.h
index fac5e44..94a6016 100644
--- a/libgit2-glib/ggit-diff.h
+++ b/libgit2-glib/ggit-diff.h
@@ -113,8 +113,8 @@ void           ggit_diff_blobs                     (GgitBlob              *old_b
 
 void           ggit_diff_blob_to_buffer            (GgitBlob              *old_blob,
                                                     const gchar           *old_as_path,
-                                                    const gchar           *buffer,
-                                                    gsize                  buffer_len,
+                                                    const guint8          *buffer,
+                                                    gssize                 buffer_len,
                                                     const gchar           *buffer_as_path,
                                                     GgitDiffOptions       *diff_options,
                                                     GgitDiffFileCallback   file_cb,