[PATCH v2 3/4] Allow for creating patch series

[Lukas Fleischer]

This allows for specifying a revision range using the id2 parameter of
/patch/. The output that is produced is similar to

    $ git format-patch --stdout id2..id

Signed-off-by: Lukas Fleischer <cgit at cryptocrack.de>
---
 cmd.c      |  2 +-
 ui-patch.c | 16 +++++++++++++---
 ui-patch.h |  2 +-
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/cmd.c b/cmd.c
index 9893710..0202917 100644
--- a/cmd.c
+++ b/cmd.c
@@ -98,7 +98,7 @@ 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 e205fda..79a6fa7 100644
--- a/ui-patch.c
+++ b/ui-patch.c
@@ -11,7 +11,7 @@
 #include "html.h"
 #include "ui-shared.h"
 
-void cgit_print_patch(char *hex, const char *prefix)
+void cgit_print_patch(char *hex, const char *old_rev, const char *prefix)
 {
 	struct rev_info rev;
 	struct commit *commit;
@@ -33,10 +33,20 @@ void cgit_print_patch(char *hex, const char *prefix)
 		return;
 	}
 
-	if (commit->parents && commit->parents->item)
+	if (old_rev) {
+		if (get_sha1(old_rev, old_sha1)) {
+			cgit_print_error("Bad object id: %s", old_rev);
+			return;
+		}
+		if (!lookup_commit_reference(old_sha1)) {
+			cgit_print_error("Bad commit reference: %s", old_rev);
+			return;
+		}
+	} else if (commit->parents && commit->parents->item) {
 		hashcpy(old_sha1, commit->parents->item->object.sha1);
-	else
+	} else {
 		hashclr(old_sha1);
+	}
 
 	sprintf(rev_range, "%s..%s", sha1_to_hex(old_sha1), sha1_to_hex(sha1));
 
diff --git a/ui-patch.h b/ui-patch.h
index 1641cea..acd37fd 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 *hex, const char *old_rev, const char *prefix);
 
 #endif /* UI_PATCH_H */
-- 
1.8.4.rc2.477.g1da3ebd