1 files changed, 17 insertions, 6 deletions

diff --git a/ui-snapshot.c b/ui-snapshot.c
index f25613e..5372f5d 100644
--- a/ui-snapshot.c
+++ b/ui-snapshot.c
@@ -135,60 +135,71 @@ static const char *get_ref_from_filename(const char *url, const char *filename,
         snapshot[strlen(snapshot) - strlen(format->suffix)] = '\0';
         fprintf(stderr, "snapshot=%s\n", snapshot);
 
         if (get_sha1(snapshot, sha1) == 0)
                 return snapshot;
 
         reponame = cgit_repobasename(url);
         fprintf(stderr, "reponame=%s\n", reponame);
         if (prefixcmp(snapshot, reponame) == 0) {
                 snapshot += strlen(reponame);
                 while (snapshot && (*snapshot == '-' || *snapshot == '_'))
                         snapshot++;
         }
 
         if (get_sha1(snapshot, sha1) == 0)
                 return snapshot;
 
         snapshot = fmt("v%s", snapshot);
         if (get_sha1(snapshot, sha1) == 0)
                 return snapshot;
 
         return NULL;
 }
 
+void show_error(char *msg)
+{
+        ctx.page.mimetype = "text/html";
+        cgit_print_http_headers(&ctx);
+        cgit_print_docstart(&ctx);
+        cgit_print_pageheader(&ctx);
+        cgit_print_error(msg);
+        cgit_print_docend();
+}
+
 void cgit_print_snapshot(const char *head, const char *hex,
                          const char *filename, int snapshots, int dwim)
 {
         const struct cgit_snapshot_format* f;
         char *prefix = NULL;
 
+        if (!filename) {
+                show_error("No snapshot name specified");
+                return;
+        }
+
         f = get_format(filename);
         if (!f) {
-                ctx.page.mimetype = "text/html";
-                cgit_print_http_headers(&ctx);
-                cgit_print_docstart(&ctx);
-                cgit_print_pageheader(&ctx);
-                cgit_print_error(fmt("Unsupported snapshot format: %s", filename));
-                cgit_print_docend();
+                show_error(xstrdup(fmt("Unsupported snapshot format: %s",
+                                       filename)));
                 return;
         }
 
         if (!hex && dwim) {
                 hex = get_ref_from_filename(ctx.repo->url, filename, f);
                 if (hex == NULL) {
                         html_status(404, "Not found", 0);
                         return;
                 }
                 prefix = xstrdup(filename);
                 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
         }
 
         if (!hex)
                 hex = head;
 
         if (!prefix)
                 prefix = xstrdup(cgit_repobasename(ctx.repo->url));
 
         make_snapshot(f, hex, prefix, filename);
         free(prefix);
 }