[PATCH/RFC] Allow for generating patch series

[Lukas Fleischer]

Signed-off-by: Lukas Fleischer <cgit at cryptocrack.de>
---
Note that this is a very first draft of a patch series introducing
revision range support for /patch/. Also, the final series will contain
an additional bug fix of an e-mail address encoding bug I noticed during
testing this.

Comments welcome.

 cmd.c      |  2 +-
 ui-patch.c | 85 +++++++++++++++++++++++++++++++++++++++-----------------------
 ui-patch.h |  2 +-
 3 files changed, 56 insertions(+), 33 deletions(-)

diff --git a/cmd.c b/cmd.c
index abe8e46..7e8b168 100644
--- a/cmd.c
+++ b/cmd.c
@@ -93,7 +93,7 @@ static void repolist_fn(struct cgit_context *ctx)
 
 static void patch_fn(struct cgit_context *ctx)
 {
-	cgit_print_patch(ctx->qry.sha1, ctx->qry.path);
+	cgit_print_patch(ctx->qry.sha1, ctx->qry.sha2, ctx->qry.path);
 }
 
 static void plain_fn(struct cgit_context *ctx)
diff --git a/ui-patch.c b/ui-patch.c
index fbb92cc..0eb48bd 100644
--- a/ui-patch.c
+++ b/ui-patch.c
@@ -83,55 +83,78 @@ static void filepair_cb(struct diff_filepair *pair)
 		html("Binary files differ\n");
 }
 
-void cgit_print_patch(char *hex, const char *prefix)
+void cgit_print_patch(char *new_rev, char *old_rev, const char *prefix)
 {
+	struct rev_info rev;
 	struct commit *commit;
 	struct commitinfo *info;
-	unsigned char sha1[20], old_sha1[20];
+	unsigned char new_sha1[20], old_sha1[20];
+	char rev_range[2 * 20 + strlen("..") + 1];
+	char *rev_argv[] = { NULL, "--reverse", rev_range };
 	char *patchname;
 
-	if (!hex)
-		hex = ctx.qry.head;
+	if (!new_rev)
+		new_rev = ctx.qry.head;
 
-	if (get_sha1(hex, sha1)) {
-		cgit_print_error("Bad object id: %s", hex);
+	if (get_sha1(new_rev, new_sha1)) {
+		cgit_print_error("Bad object id: %s", new_rev);
 		return;
 	}
-	commit = lookup_commit_reference(sha1);
+	commit = lookup_commit_reference(new_sha1);
 	if (!commit) {
-		cgit_print_error("Bad commit reference: %s", hex);
+		cgit_print_error("Bad commit reference: %s", new_rev);
 		return;
 	}
-	info = cgit_parse_commit(commit);
 
-	if (commit->parents && commit->parents->item)
+	if (old_rev)
+		get_sha1(old_rev, old_sha1);
+	else if (commit->parents && commit->parents->item)
 		hashcpy(old_sha1, commit->parents->item->object.sha1);
 	else
 		hashclr(old_sha1);
 
-	patchname = fmt("%s.patch", sha1_to_hex(sha1));
+	if (old_rev)
+		patchname = fmt("%s..%s.patch", sha1_to_hex(old_sha1), sha1_to_hex(new_sha1));
+	else
+		patchname = fmt("%s.patch", sha1_to_hex(new_sha1));
+
 	ctx.page.mimetype = "text/plain";
 	ctx.page.filename = patchname;
 	cgit_print_http_headers(&ctx);
-	htmlf("From %s Mon Sep 17 00:00:00 2001\n", sha1_to_hex(sha1));
-	htmlf("From: %s", info->author);
-	if (!ctx.cfg.noplainemail) {
-		htmlf(" %s", info->author_email);
-	}
-	html("\n");
-	html("Date: ");
-	cgit_print_date(info->author_date, "%a, %d %b %Y %H:%M:%S %z%n", ctx.cfg.local_time);
-	htmlf("Subject: %s\n\n", info->subject);
-	if (info->msg && *info->msg) {
-		htmlf("%s", info->msg);
-		if (info->msg[strlen(info->msg) - 1] != '\n')
-			html("\n");
+
+	sprintf(rev_range, "%s..%s", sha1_to_hex(old_sha1),
+	        sha1_to_hex(new_sha1));
+
+	init_revisions(&rev, NULL);
+	rev.abbrev = DEFAULT_ABBREV;
+	rev.commit_format = CMIT_FMT_EMAIL;
+	rev.verbose_header = 1;
+	rev.show_root_diff = 0;
+	setup_revisions(3, rev_argv, &rev, NULL);
+	prepare_revision_walk(&rev);
+
+	while ((commit = get_revision(&rev)) != NULL) {
+		info = cgit_parse_commit(commit);
+		htmlf("From %s Mon Sep 17 00:00:00 2001\n", sha1_to_hex(commit->object.sha1));
+		htmlf("From: %s", info->author);
+		if (!ctx.cfg.noplainemail) {
+			htmlf(" %s", info->author_email);
+		}
+		html("\n");
+		html("Date: ");
+		cgit_print_date(info->author_date, "%a, %d %b %Y %H:%M:%S %z%n", ctx.cfg.local_time);
+		htmlf("Subject: %s\n\n", info->subject);
+		if (info->msg && *info->msg) {
+			htmlf("%s", info->msg);
+			if (info->msg[strlen(info->msg) - 1] != '\n')
+				html("\n");
+		}
+		html("---\n");
+		if (prefix)
+			htmlf("(limited to '%s')\n\n", prefix);
+		cgit_diff_tree(commit->parents->item->object.sha1, commit->object.sha1, filepair_cb, prefix, 0);
+		html("--\n");
+		htmlf("cgit %s\n\n", cgit_version);
+		cgit_free_commitinfo(info);
 	}
-	html("---\n");
-	if (prefix)
-		htmlf("(limited to '%s')\n\n", prefix);
-	cgit_diff_tree(old_sha1, sha1, filepair_cb, prefix, 0);
-	html("--\n");
-	htmlf("cgit %s\n", cgit_version);
-	cgit_free_commitinfo(info);
 }
diff --git a/ui-patch.h b/ui-patch.h
index 1641cea..d65d594 100644
--- a/ui-patch.h
+++ b/ui-patch.h
@@ -1,6 +1,6 @@
 #ifndef UI_PATCH_H
 #define UI_PATCH_H
 
-extern void cgit_print_patch(char *hex, const char *prefix);
+extern void cgit_print_patch(char *new_rev, char *old_rev, const char *prefix);
 
 #endif /* UI_PATCH_H */
-- 
1.8.4.rc2.477.g1da3ebd