Add support for downloading single blobs

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

ui-blob.c

@@ -0,0 +1,31 @@
+#include "cgit.h"
+
+void cgit_print_blob(struct cacheitem *item, const char *hex, char *path)
+{
+
+	unsigned char sha1[20];
+	enum object_type type;
+	unsigned char *buf;
+	unsigned long size;
+
+	if (get_sha1_hex(hex, sha1)){
+		cgit_print_error(fmt("Bad hex value: %s", hex));
+	        return;
+	}
+
+	type = sha1_object_info(sha1, &size);
+	if (type == OBJ_BAD) {
+		cgit_print_error(fmt("Bad object name: %s", hex));
+		return;
+	}
+
+	buf = read_sha1_file(sha1, &type, &size);
+	if (!buf) {
+		cgit_print_error(fmt("Error reading object %s", hex));
+		return;
+	}
+
+	buf[size] = '\0';
+	cgit_print_snapshot_start("text/plain", path, item);
+	write(htmlfd, buf, size);
+}