[PATCH/RFC 1/2] ui-diff: Use diff_tree_sha1() for raw diff formatting

[cgit at cryptocrack.de (Lukas Fleischer)]

Use Git's internal diff_tree_sha1() function for the /rawdiff/ command
instead of trying to recreate this functionality.

Signed-off-by: Lukas Fleischer <cgit at cryptocrack.de>
---
The test suite still passes. If anybody has any idea how to do this
better: Comments welcome.

 ui-diff.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/ui-diff.c b/ui-diff.c
index 1209c47..c602494 100644
--- a/ui-diff.c
+++ b/ui-diff.c
@@ -360,7 +360,7 @@ void cgit_print_diff_ctrls()
 void cgit_print_diff(const char *new_rev, const char *old_rev,
 		     const char *prefix, int show_ctrls, int raw)
 {
-	struct commit *commit, *commit2;
+	struct commit *commit, *commit2 = NULL;
 
 	if (!new_rev)
 		new_rev = ctx.qry.head;
@@ -394,10 +394,32 @@ void cgit_print_diff(const char *new_rev, const char *old_rev,
 	}
 
 	if (raw) {
+		unsigned char old_tree_sha1[20], new_tree_sha1[20];
+		struct diff_options diffopt;
+
+		memcpy(new_tree_sha1, commit->tree->object.sha1, 20);
+		if (commit2) {
+			memcpy(old_tree_sha1, commit2->tree->object.sha1, 20);
+		} else {
+			/*
+			 * SHA-1 of an empty tree. We might be better off not
+			 * hardcoding this.
+			 */
+			get_sha1("4b825dc642cb6eb9a060e54bf8d69288fbee4904",
+				 old_tree_sha1);
+		}
+
+		diff_setup(&diffopt);
+		diffopt.output_format = DIFF_FORMAT_PATCH;
+		DIFF_OPT_SET(&diffopt, RECURSIVE);
+		diff_setup_done(&diffopt);
+
 		ctx.page.mimetype = "text/plain";
 		cgit_print_http_headers(&ctx);
-		cgit_diff_tree(old_rev_sha1, new_rev_sha1, filepair_cb_raw,
-			       prefix, 0);
+		diff_tree_sha1(old_tree_sha1, new_tree_sha1, "", &diffopt);
+		diffcore_std(&diffopt);
+		diff_flush(&diffopt);
+
 		return;
 	}
 
-- 
1.8.4.rc3.500.gc3113b0