1 files changed, 14 insertions, 6 deletions
diff --git a/src/Common/libzip/zip_source_layered.c b/src/Common/libzip/zip_source_layered.c
index 3c21441a..62b78e68 100644
--- a/src/Common/libzip/zip_source_layered.c
+++ b/src/Common/libzip/zip_source_layered.c
@@ -49,19 +49,27 @@ zip_source_layered(zip_t *za, zip_source_t *src, zip_source_layered_callback cb,
 zip_source_t *
 zip_source_layered_create(zip_source_t *src, zip_source_layered_callback cb, void *ud, zip_error_t *error) {
     zip_source_t *zs;
+    zip_int64_t lower_supports, supports;
 
-    if ((zs = _zip_source_new(error)) == NULL)
+    lower_supports = zip_source_supports(src);
+    supports = cb(src, ud, &lower_supports, sizeof(lower_supports), ZIP_SOURCE_SUPPORTS);
+    if (supports < 0) {
+        zip_error_set(error,ZIP_ER_INVAL, 0); /* Initialize in case cb doesn't return valid error. */
+        cb(src, ud, error, sizeof(*error), ZIP_SOURCE_ERROR);
         return NULL;
+    }
+
+    if ((zs = _zip_source_new(error)) == NULL) {
+        return NULL;
+    }
 
-    zip_source_keep(src);
     zs->src = src;
     zs->cb.l = cb;
     zs->ud = ud;
+    zs->supports = supports;
 
-    zs->supports = cb(src, ud, NULL, 0, ZIP_SOURCE_SUPPORTS);
-    if (zs->supports < 0) {
-        zs->supports = ZIP_SOURCE_SUPPORTS_READABLE;
-    }
+    /* Layered sources can't support writing, since we currently have no use case. If we want to revisit this, we have to define how the two sources interact. */
+    zs->supports &= ~(ZIP_SOURCE_SUPPORTS_WRITABLE & ~ZIP_SOURCE_SUPPORTS_SEEKABLE);
 
     return zs;
 }