2 files changed, 19 insertions, 1 deletions
diff --git a/tests/files.cpp b/tests/files.cpp
index e1a38421..04baa151 100644
--- a/tests/files.cpp
+++ b/tests/files.cpp
@@ -1,6 +1,7 @@
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 int main()
 {
@@ -103,6 +104,23 @@ int main()
   fclose(inf);
   printf("fscanfed: %d - %s\n", number, text);
 
+  // temp files
+  const char *tname = "file_XXXXXX.txt";
+  char tname1[100];
+  char tname2[100];
+  strcpy(tname1, tname);
+  strcpy(tname2, tname);
+  assert(!strcmp(tname1, tname2)); // equal
+  int f1 = mkstemp(tname1);
+  int f2 = mkstemp(tname2);
+  assert(f1 != f2);
+  //printf("%d,%d,%s,%s\n", f1, f2, tname1, tname2);
+  assert(strcmp(tname1, tname2)); // not equal
+  assert(fopen(tname1, "r"));
+  assert(fopen(tname2, "r"));
+  assert(!fopen(tname2+1, "r")); // sanity check that we can't open just anything
+  printf("ok.\n");
+
   return 0;
 }
 
diff --git a/tests/runner.py b/tests/runner.py
index 97ec3b94..1ab5c7af 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -5021,7 +5021,7 @@ def process(filename):
       other.close()
 
       src = open(path_from_root('tests', 'files.cpp'), 'r').read()
-      self.do_run(src, 'size: 7\ndata: 100,-56,50,25,10,77,123\nloop: 100 -56 50 25 10 77 123 \ninput:hi there!\ntexto\ntexte\n$\n5 : 10,30,20,11,88\nother=some data.\nseeked=me da.\nseeked=ata.\nseeked=ta.\nfscanfed: 10 - hello\n',
+      self.do_run(src, 'size: 7\ndata: 100,-56,50,25,10,77,123\nloop: 100 -56 50 25 10 77 123 \ninput:hi there!\ntexto\ntexte\n$\n5 : 10,30,20,11,88\nother=some data.\nseeked=me da.\nseeked=ata.\nseeked=ta.\nfscanfed: 10 - hello\nok.\n',
                    post_build=post, extra_emscripten_args=['-H', 'libc/fcntl.h'])
 
     def test_files_m(self):