re-add Windows tmpfile checks in test code

Author: JohannesGaessler

tests/test-gguf.cpp

@@ -157,6 +157,10 @@ static void helper_write(FILE * file, const void * data, const size_t nbytes) {
 static FILE * get_handcrafted_file(const unsigned int seed, const enum handcrafted_file_type hft, const int extra_bytes = 0) {
     FILE * file = tmpfile();
 
+    if (!file) {
+        return file;
+    }
+
     std::mt19937 rng(seed);
     uint32_t alignment = GGUF_DEFAULT_ALIGNMENT;
 
@@ -693,6 +697,16 @@ static std::pair<int, int> test_handcrafted_file(const unsigned int seed) {
         printf("%s: handcrafted_file_type=%s\n", __func__, handcrafted_file_type_name(hft).c_str());
         FILE * file = get_handcrafted_file(seed, hft);
 
+#ifdef _WIN32
+        if (!file) {
+            printf("%s: failed to create tmpfile(), needs elevated privileges on Windows");
+            printf("%s: skipping tests");
+            continue;
+        }
+#else
+        GGML_ASSERT(file);
+#endif // _WIN32
+
         struct ggml_context * ctx = nullptr;
         struct gguf_init_params gguf_params = {
             /*no_alloc =*/ false,
@@ -1065,6 +1079,17 @@ static std::pair<int, int> test_roundtrip(ggml_backend_dev_t dev, const unsigned
     }
 
     FILE * file = tmpfile();
+
+#ifdef _WIN32
+    if (!file) {
+        printf("%s: failed to create tmpfile(), needs elevated privileges on Windows");
+        printf("%s: skipping tests");
+        return;
+    }
+#else
+    GGML_ASSERT(file);
+#endif // _WIN32
+
     {
         std::vector<int8_t> buf;
         gguf_write_to_buf(gguf_ctx_0, buf, only_meta);