Check `max-blob-size` before reading, default 10 MB

Only the tree view honoured the limit, and only after loading the
whole object. The raw blob, plain, blame and readme paths now check
the size before reading, and the default moves from unlimited to
10 MB so a fresh install never buffers a huge object whole, with zero
still the opt-out.

1 file changed, 8 insertions, 7 deletions

diff --git a/source/ui-tree.c b/source/ui-tree.c
index 292bfc6..f820f1f 100644
--- a/source/ui-tree.c
+++ b/source/ui-tree.c
@@ -117,6 +117,14 @@ static int print_object(const struct object_id *oid, const char *path, const cha
 		return 0;
 	}
 
+	/* Reject an oversized object before reading it whole into memory. */
+	if (ctx.cfg.max_blob_size && size / 1024 > (unsigned long)ctx.cfg.max_blob_size) {
+		cgit_print_error_page(413, "Too large",
+			"blob size (%luKB) exceeds display size limit (%dKB)",
+			size / 1024, ctx.cfg.max_blob_size);
+		return 0;
+	}
+
 	buf = odb_read_object(the_repository->objects, oid, &type, &size);
 	if (!buf) {
 		cgit_print_error_page(500, "Internal server error",
@@ -138,13 +146,6 @@ static int print_object(const struct object_id *oid, const char *path, const cha
 	}
 	html(")\n");
 
-	if (ctx.cfg.max_blob_size && size / 1024 > ctx.cfg.max_blob_size) {
-		htmlf("<div class='error'>blob size (%ldKB) exceeds display size limit (%dKB).</div>",
-				size / 1024, ctx.cfg.max_blob_size);
-		free(buf);
-		return 1;
-	}
-
 	if (is_binary)
 		print_binary_buffer(buf, size);
 	else