1 files changed, 125 insertions, 6 deletions

diff --git a/src/diff_print.c b/src/diff_print.c
index a7f7b6fe8..e54155458 100644
--- a/src/diff_print.c
+++ b/src/diff_print.c
@@ -8,6 +8,9 @@
 #include "diff.h"
 #include "diff_patch.h"
 #include "fileops.h"
+#include "zstream.h"
+#include "blob.h"
+#include "delta.h"
 #include "git2/sys/diff.h"
 
 typedef struct {
@@ -37,6 +40,8 @@ static int diff_print_info_init(
 
 	if (diff)
 		pi->flags = diff->opts.flags;
+	else
+		pi->flags = 0;
 
 	if (diff && diff->opts.id_abbrev != 0)
 		pi->oid_strlen = diff->opts.id_abbrev;
@@ -276,6 +281,118 @@ int git_diff_delta__format_file_header(
 	return git_buf_oom(out) ? -1 : 0;
 }
 
+static int print_binary_hunk(diff_print_info *pi, git_blob *old, git_blob *new)
+{
+	git_buf deflate = GIT_BUF_INIT, delta = GIT_BUF_INIT, *out = NULL;
+	const void *old_data, *new_data;
+	size_t old_data_len, new_data_len, delta_data_len, inflated_len, remain;
+	const char *out_type = "literal";
+	char *ptr;
+	int error;
+
+	old_data = old ? git_blob_rawcontent(old) : NULL;
+	new_data = new ? git_blob_rawcontent(new) : NULL;
+
+	old_data_len = old ? (size_t)git_blob_rawsize(old) : 0;
+	new_data_len = new ? (size_t)git_blob_rawsize(new) : 0;
+
+	out = &deflate;
+	inflated_len = new_data_len;
+
+	if ((error = git_zstream_deflatebuf(
+		&deflate, new_data, new_data_len)) < 0)
+		goto done;
+
+	if (old && new) {
+		void *delta_data;
+
+		delta_data = git_delta(old_data, old_data_len, new_data,
+			new_data_len, &delta_data_len, deflate.size);
+
+		if (delta_data) {
+			error = git_zstream_deflatebuf(&delta, delta_data, delta_data_len);
+			free(delta_data);
+
+			if (error < 0)
+				goto done;
+
+			if (delta.size < deflate.size) {
+				out = &delta;
+				out_type = "delta";
+				inflated_len = delta_data_len;
+			}
+		}
+	}
+
+	git_buf_printf(pi->buf, "%s %" PRIuZ "\n", out_type, inflated_len);
+	pi->line.num_lines++;
+
+	for (ptr = out->ptr, remain = out->size; remain > 0; ) {
+		size_t chunk_len = (52 < remain) ? 52 : remain;
+
+		if (chunk_len <= 26)
+			git_buf_putc(pi->buf, chunk_len + 'A' - 1);
+		else
+			git_buf_putc(pi->buf, chunk_len - 26 + 'a' - 1);
+
+		git_buf_put_base85(pi->buf, ptr, chunk_len);
+		git_buf_putc(pi->buf, '\n');
+
+		if (git_buf_oom(pi->buf)) {
+			error = -1;
+			goto done;
+		}
+
+		ptr += chunk_len;
+		remain -= chunk_len;
+		pi->line.num_lines++;
+	}
+
+done:
+	git_buf_free(&deflate);
+	git_buf_free(&delta);
+
+	return error;
+}
+
+/* git diff --binary 8d7523f~2 8d7523f~1 */
+static int diff_print_patch_file_binary(
+	diff_print_info *pi, const git_diff_delta *delta,
+	const char *oldpfx, const char *newpfx)
+{
+	git_blob *old = NULL, *new = NULL;
+	const git_oid *old_id, *new_id;
+	int error;
+
+	if ((pi->flags & GIT_DIFF_SHOW_BINARY) == 0) {
+		pi->line.num_lines = 1;
+		return diff_delta_format_with_paths(
+			pi->buf, delta, oldpfx, newpfx,
+				"Binary files %s%s and %s%s differ\n");
+	}
+
+	git_buf_printf(pi->buf, "GIT binary patch\n");
+	pi->line.num_lines++;
+
+	old_id = (delta->status != GIT_DELTA_ADDED) ? &delta->old_file.id : NULL;
+	new_id = (delta->status != GIT_DELTA_DELETED) ? &delta->new_file.id : NULL;
+
+	if ((old_id && (error = git_blob_lookup(&old, pi->diff->repo, old_id)) < 0) ||
+		(new_id && (error = git_blob_lookup(&new, pi->diff->repo,new_id)) < 0) ||
+		(error = print_binary_hunk(pi, old, new)) < 0 ||
+		(error = git_buf_putc(pi->buf, '\n')) < 0 ||
+		(error = print_binary_hunk(pi, new, old)) < 0)
+		goto done;
+
+	pi->line.num_lines++;
+
+done:
+	git_blob_free(old);
+	git_blob_free(new);
+
+	return error;
+}
+
 static int diff_print_patch_file(
 	const git_diff_delta *delta, float progress, void *data)
 {
@@ -286,6 +403,11 @@ static int diff_print_patch_file(
 	const char *newpfx =
 		pi->diff ? pi->diff->opts.new_prefix : DIFF_NEW_PREFIX_DEFAULT;
 
+	bool binary = !!(delta->flags & GIT_DIFF_FLAG_BINARY);
+	bool show_binary = !!(pi->flags & GIT_DIFF_SHOW_BINARY);
+	int oid_strlen = binary && show_binary ?
+		GIT_OID_HEXSZ + 1 : pi->oid_strlen;
+
 	GIT_UNUSED(progress);
 
 	if (S_ISDIR(delta->new_file.mode) ||
@@ -296,7 +418,7 @@ static int diff_print_patch_file(
 		return 0;
 
 	if ((error = git_diff_delta__format_file_header(
-			pi->buf, delta, oldpfx, newpfx, pi->oid_strlen)) < 0)
+			pi->buf, delta, oldpfx, newpfx, oid_strlen)) < 0)
 		return error;
 
 	pi->line.origin      = GIT_DIFF_LINE_FILE_HDR;
@@ -306,20 +428,17 @@ static int diff_print_patch_file(
 	if ((error = pi->print_cb(delta, NULL, &pi->line, pi->payload)) != 0)
 		return error;
 
-	if ((delta->flags & GIT_DIFF_FLAG_BINARY) == 0)
+	if (!binary)
 		return 0;
 
 	git_buf_clear(pi->buf);
 
-	if ((error = diff_delta_format_with_paths(
-			pi->buf, delta, oldpfx, newpfx,
-			"Binary files %s%s and %s%s differ\n")) < 0)
+	if ((error = diff_print_patch_file_binary(pi, delta, oldpfx, newpfx)) < 0)
 		return error;
 
 	pi->line.origin      = GIT_DIFF_LINE_BINARY;
 	pi->line.content     = git_buf_cstr(pi->buf);
 	pi->line.content_len = git_buf_len(pi->buf);
-	pi->line.num_lines   = 1;
 
 	return pi->print_cb(delta, NULL, &pi->line, pi->payload);
 }