refactor: add assertion for v_blob in tv_ptr() (#29554)

Also add test for using printf() and id() with a Blob.

2 files changed, 7 insertions, 2 deletions

diff --git a/src/nvim/strings.c b/src/nvim/strings.c
index bf7af40a38..0aaa100bf2 100644
--- a/src/nvim/strings.c
+++ b/src/nvim/strings.c
@@ -629,12 +629,14 @@ static const void *tv_ptr(const typval_T *const tvs, int *const idxp)
 #define OFF(attr) offsetof(union typval_vval_union, attr)
   STATIC_ASSERT(OFF(v_string) == OFF(v_list)
                 && OFF(v_string) == OFF(v_dict)
+                && OFF(v_string) == OFF(v_blob)
                 && OFF(v_string) == OFF(v_partial)
                 && sizeof(tvs[0].vval.v_string) == sizeof(tvs[0].vval.v_list)
                 && sizeof(tvs[0].vval.v_string) == sizeof(tvs[0].vval.v_dict)
+                && sizeof(tvs[0].vval.v_string) == sizeof(tvs[0].vval.v_blob)
                 && sizeof(tvs[0].vval.v_string) == sizeof(tvs[0].vval.v_partial),
-                "Strings, dictionaries, lists and partials are expected to be pointers, "
-                "so that all three of them can be accessed via v_string");
+                "Strings, Dictionaries, Lists, Blobs and Partials are expected to be pointers, "
+                "so that all of them can be accessed via v_string");
 #undef OFF
   const int idx = *idxp - 1;
   if (tvs[idx].v_type == VAR_UNKNOWN) {
diff --git a/test/functional/vimscript/printf_spec.lua b/test/functional/vimscript/printf_spec.lua
index 3c66e07618..1fd5c3c9b6 100644
--- a/test/functional/vimscript/printf_spec.lua
+++ b/test/functional/vimscript/printf_spec.lua
@@ -84,10 +84,13 @@ describe('printf()', function()
       end
       api.nvim_del_var('__result')
     end
+    check_printf('v:_null_string', true)
     check_printf('v:_null_list', true)
     check_printf('v:_null_dict', true)
+    check_printf('v:_null_blob', true)
     check_printf('[]')
     check_printf('{}')
+    check_printf('0z')
     check_printf('function("tr", ["a"])')
   end)
 end)