thodg/libgit2

diff --git a/include/git2/diff.h b/include/git2/diff.h
index 6afa608..f0f4502 100644
--- a/include/git2/diff.h
+++ b/include/git2/diff.h
@@ -343,6 +343,7 @@ GIT_EXTERN(int) git_diff_blobs(
 	git_blob *new_blob,
 	git_diff_options *options,
 	void *cb_data,
+	git_diff_file_fn file_cb,
 	git_diff_hunk_fn hunk_cb,
 	git_diff_data_fn line_cb);
 
diff --git a/src/diff_output.c b/src/diff_output.c
index dbcc89f..dadbe28 100644
--- a/src/diff_output.c
+++ b/src/diff_output.c
@@ -298,6 +298,16 @@ static void release_content(git_diff_file *file, git_map *map, git_blob *blob)
 	}
 }
 
+static void fill_map_from_mmfile(git_map *dst, mmfile_t *src) {
+	assert(dst && src);
+
+	dst->data = src->ptr;
+	dst->len = src->size;
+#ifdef GIT_WIN32
+	dst->fmh = NULL;
+#endif
+}
+
 int git_diff_foreach(
 	git_diff_list *diff,
 	void *data,
@@ -691,12 +701,14 @@ int git_diff_blobs(
 	git_blob *new_blob,
 	git_diff_options *options,
 	void *cb_data,
+	git_diff_file_fn file_cb,
 	git_diff_hunk_fn hunk_cb,
 	git_diff_data_fn line_cb)
 {
 	diff_output_info info;
 	git_diff_delta delta;
 	mmfile_t old_data, new_data;
+	git_map old_map, new_map;
 	xpparam_t xdiff_params;
 	xdemitconf_t xdiff_config;
 	xdemitcb_t xdiff_callback;
@@ -738,6 +750,22 @@ int git_diff_blobs(
 	delta.old_file.size = old_data.size;
 	delta.new_file.size = new_data.size;
 
+	fill_map_from_mmfile(&old_map, &old_data);
+	fill_map_from_mmfile(&new_map, &new_data);
+
+	if (file_is_binary_by_content(&delta, &old_map, &new_map) < 0)
+		return -1;
+
+	if (file_cb != NULL) {
+		int error = file_cb(cb_data, &delta, 1);
+		if (error < 0)
+			return error;
+	}
+
+	/* don't do hunk and line diffs if file is binary */
+	if (delta.binary == 1)
+		return 0;
+
 	info.diff    = NULL;
 	info.delta   = &delta;
 	info.cb_data = cb_data;
diff --git a/tests-clar/diff/blob.c b/tests-clar/diff/blob.c
index 9364bdc..1bcb1f8 100644
--- a/tests-clar/diff/blob.c
+++ b/tests-clar/diff/blob.c
@@ -4,11 +4,11 @@
 static git_repository *g_repo = NULL;
 static diff_expects exp;
 static git_diff_options opts;
-static git_blob *d;
+static git_blob *d, *alien;
 
 void test_diff_blob__initialize(void)
 {
-	git_oid d_oid;
+	git_oid oid;
 
 	g_repo = cl_git_sandbox_init("attr");
 
@@ -19,13 +19,18 @@ void test_diff_blob__initialize(void)
 	memset(&exp, 0, sizeof(exp));
 
 	/* tests/resources/attr/root_test4.txt */
-	cl_git_pass(git_oid_fromstrn(&d_oid, "fe773770c5a6", 12));
-	cl_git_pass(git_blob_lookup_prefix(&d, g_repo, &d_oid, 6));
+	cl_git_pass(git_oid_fromstrn(&oid, "fe773770c5a6", 12));
+	cl_git_pass(git_blob_lookup_prefix(&d, g_repo, &oid, 6));
+
+	/* alien.png */
+	cl_git_pass(git_oid_fromstrn(&oid, "edf3dcee", 8));
+	cl_git_pass(git_blob_lookup_prefix(&alien, g_repo, &oid, 4));
 }
 
 void test_diff_blob__cleanup(void)
 {
 	git_blob_free(d);
+	git_blob_free(alien);
 
 	cl_git_sandbox_cleanup();
 }
@@ -50,7 +55,11 @@ void test_diff_blob__can_compare_text_blobs(void)
 	/* Doing the equivalent of a `git diff -U1` on these files */
 
 	cl_git_pass(git_diff_blobs(
-		a, b, &opts, &exp, diff_hunk_fn, diff_line_fn));
+		a, b, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	cl_assert(exp.files == 1);
+	cl_assert(exp.file_mods == 1);
+	cl_assert(exp.at_least_one_of_them_is_binary == false);
 
 	cl_assert(exp.hunks == 1);
 	cl_assert(exp.lines == 6);
@@ -60,7 +69,11 @@ void test_diff_blob__can_compare_text_blobs(void)
 
 	memset(&exp, 0, sizeof(exp));
 	cl_git_pass(git_diff_blobs(
-		b, c, &opts, &exp, diff_hunk_fn, diff_line_fn));
+		b, c, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	cl_assert(exp.files == 1);
+	cl_assert(exp.file_mods == 1);
+	cl_assert(exp.at_least_one_of_them_is_binary == false);
 
 	cl_assert(exp.hunks == 1);
 	cl_assert(exp.lines == 15);
@@ -70,7 +83,11 @@ void test_diff_blob__can_compare_text_blobs(void)
 
 	memset(&exp, 0, sizeof(exp));
 	cl_git_pass(git_diff_blobs(
-		a, c, &opts, &exp, diff_hunk_fn, diff_line_fn));
+		a, c, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	cl_assert(exp.files == 1);
+	cl_assert(exp.file_mods == 1);
+	cl_assert(exp.at_least_one_of_them_is_binary == false);
 
 	cl_assert(exp.hunks == 1);
 	cl_assert(exp.lines == 13);
@@ -82,7 +99,11 @@ void test_diff_blob__can_compare_text_blobs(void)
 
 	memset(&exp, 0, sizeof(exp));
 	cl_git_pass(git_diff_blobs(
-		c, d, &opts, &exp, diff_hunk_fn, diff_line_fn));
+		c, d, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	cl_assert(exp.files == 1);
+	cl_assert(exp.file_mods == 1);
+	cl_assert(exp.at_least_one_of_them_is_binary == false);
 
 	cl_assert(exp.hunks == 2);
 	cl_assert(exp.lines == 14);
@@ -100,7 +121,11 @@ void test_diff_blob__can_compare_against_null_blobs(void)
 	git_blob *e = NULL;
 
 	cl_git_pass(git_diff_blobs(
-		d, e, &opts, &exp, diff_hunk_fn, diff_line_fn));
+		d, e, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	cl_assert(exp.files == 1);
+	cl_assert(exp.file_dels == 1);
+	cl_assert(exp.at_least_one_of_them_is_binary == false);
 
 	cl_assert(exp.hunks == 1);
 	cl_assert(exp.hunk_old_lines == 14);
@@ -111,10 +136,88 @@ void test_diff_blob__can_compare_against_null_blobs(void)
 	memset(&exp, 0, sizeof(exp));
 
 	cl_git_pass(git_diff_blobs(
-		d, e, &opts, &exp, diff_hunk_fn, diff_line_fn));
+		d, e, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	cl_assert(exp.files == 1);
+	cl_assert(exp.file_adds == 1);
+	cl_assert(exp.at_least_one_of_them_is_binary == false);
 
 	cl_assert(exp.hunks == 1);
 	cl_assert(exp.hunk_new_lines == 14);
 	cl_assert(exp.lines == 14);
 	cl_assert(exp.line_adds == 14);
+
+	opts.flags ^= GIT_DIFF_REVERSE;
+	memset(&exp, 0, sizeof(exp));
+
+	cl_git_pass(git_diff_blobs(
+		alien, NULL, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	cl_assert(exp.at_least_one_of_them_is_binary == true);
+
+	cl_assert(exp.files == 1);
+	cl_assert(exp.file_dels == 1);
+	cl_assert(exp.hunks == 0);
+	cl_assert(exp.lines == 0);
+
+	memset(&exp, 0, sizeof(exp));
+
+	cl_git_pass(git_diff_blobs(
+		NULL, alien, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	cl_assert(exp.at_least_one_of_them_is_binary == true);
+
+	cl_assert(exp.files == 1);
+	cl_assert(exp.file_adds == 1);
+	cl_assert(exp.hunks == 0);
+	cl_assert(exp.lines == 0);
+}
+
+void assert_binary_blobs_comparison(diff_expects exp)
+{
+	cl_assert(exp.at_least_one_of_them_is_binary == true);
+
+	cl_assert(exp.files == 1);
+	cl_assert(exp.file_mods == 1);
+	cl_assert(exp.hunks == 0);
+	cl_assert(exp.lines == 0);
+}
+
+void test_diff_blob__can_compare_two_binary_blobs(void)
+{
+	git_blob *heart;
+	git_oid h_oid;
+
+	/* heart.png */
+	cl_git_pass(git_oid_fromstrn(&h_oid, "de863bff", 8));
+	cl_git_pass(git_blob_lookup_prefix(&heart, g_repo, &h_oid, 4));
+
+	cl_git_pass(git_diff_blobs(
+		alien, heart, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	assert_binary_blobs_comparison(exp);
+
+	memset(&exp, 0, sizeof(exp));
+
+	cl_git_pass(git_diff_blobs(
+		heart, alien, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	assert_binary_blobs_comparison(exp);
+
+	git_blob_free(heart);
+}
+
+void test_diff_blob__can_compare_a_binary_blob_and_a_text_blob(void)
+{
+	cl_git_pass(git_diff_blobs(
+		alien, d, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	assert_binary_blobs_comparison(exp);
+
+	memset(&exp, 0, sizeof(exp));
+
+	cl_git_pass(git_diff_blobs(
+		d, alien, &opts, &exp, diff_file_fn, diff_hunk_fn, diff_line_fn));
+
+	assert_binary_blobs_comparison(exp);
 }
diff --git a/tests-clar/diff/diff_helpers.c b/tests-clar/diff/diff_helpers.c
index 74a44ab..b12d888 100644
--- a/tests-clar/diff/diff_helpers.c
+++ b/tests-clar/diff/diff_helpers.c
@@ -30,6 +30,8 @@ int diff_file_fn(
 
 	GIT_UNUSED(progress);
 
+	e->	at_least_one_of_them_is_binary = delta->binary;
+
 	e->files++;
 	switch (delta->status) {
 	case GIT_DELTA_ADDED: e->file_adds++; break;
diff --git a/tests-clar/diff/diff_helpers.h b/tests-clar/diff/diff_helpers.h
index ca8c401..994af0f 100644
--- a/tests-clar/diff/diff_helpers.h
+++ b/tests-clar/diff/diff_helpers.h
@@ -20,6 +20,8 @@ typedef struct {
 	int line_ctxt;
 	int line_adds;
 	int line_dels;
+
+	bool at_least_one_of_them_is_binary;
 } diff_expects;
 
 extern int diff_file_fn(