stat-time tests fix for Windows

[Bruno Haible]

On native Windows, the 'test-stat-time' test works fine the first time I run it,
but fails in subsequent runs in the same build directory.

Strangely enough, when you create a file, delete it, create it again (with the
same name), then the st_ctime field will contain the time of the first creation.
(See log appended below.) Reproduced with Windows 10 on NTFS.

As a workaround/fix: Let the stat-time test create files with different names
each time.


2017-05-14  Bruno Haible  <address@hidden>

        stat-time tests: Workaround for native Windows.
        * tests/test-stat-time.c: Include <stdio.h>, <time.h>.
        (filename_stamp1, filename_testfile, filename_stamp2, filename_stamp3):
        New variables.
        (initialize_filenames): New function.
        (main): Invoke it.
        (cleanup, prepare_test): Update.

diff --git a/tests/test-stat-time.c b/tests/test-stat-time.c
index 7b9cebf..25fe6c3 100644
--- a/tests/test-stat-time.c
+++ b/tests/test-stat-time.c
@@ -22,8 +22,10 @@
 
 #include <fcntl.h>
 #include <signal.h>
+#include <stdio.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <time.h>
 
 #include "macros.h"
 
@@ -32,6 +34,25 @@
 
 enum { NFILES = 4 };
 
+static char filename_stamp1[50];
+static char filename_testfile[50];
+static char filename_stamp2[50];
+static char filename_stamp3[50];
+
+/* Use file names that are different at each run.
+   This is necessary for test_birthtime() to pass on native Windows:
+   On this platform, the file system apparently remembers the creation time
+   of a file even after it is removed and created anew.  */
+static void
+initialize_filenames (void)
+{
+  long t = (long) time (NULL);
+  sprintf (filename_stamp1,   "t-stt-%ld-stamp1", t);
+  sprintf (filename_testfile, "t-stt-%ld-testfile", t);
+  sprintf (filename_stamp2,   "t-stt-%ld-stamp2", t);
+  sprintf (filename_stamp3,   "t-stt-%ld-stamp3", t);
+}
+
 static int
 force_unlink (const char *filename)
 {
@@ -45,11 +66,10 @@ static void
 cleanup (int sig)
 {
   /* Remove temporary files.  */
-  force_unlink ("t-stt-stamp1");
-  force_unlink ("t-stt-testfile");
-  force_unlink ("t-stt-stamp2");
-  force_unlink ("t-stt-renamed");
-  force_unlink ("t-stt-stamp3");
+  force_unlink (filename_stamp1);
+  force_unlink (filename_testfile);
+  force_unlink (filename_stamp2);
+  force_unlink (filename_stamp3);
 
   if (sig != 0)
     _exit (1);
@@ -87,20 +107,20 @@ prepare_test (struct stat *statinfo, struct timespec 
*modtimes)
 {
   int i;
 
-  create_file ("t-stt-stamp1");
+  create_file (filename_stamp1);
   nap ();
-  create_file ("t-stt-testfile");
+  create_file (filename_testfile);
   nap ();
-  create_file ("t-stt-stamp2");
+  create_file (filename_stamp2);
   nap ();
-  ASSERT (chmod ("t-stt-testfile", 0400) == 0);
+  ASSERT (chmod (filename_testfile, 0400) == 0);
   nap ();
-  create_file ("t-stt-stamp3");
+  create_file (filename_stamp3);
 
-  do_stat ("t-stt-stamp1",  &statinfo[0]);
-  do_stat ("t-stt-testfile", &statinfo[1]);
-  do_stat ("t-stt-stamp2",  &statinfo[2]);
-  do_stat ("t-stt-stamp3",  &statinfo[3]);
+  do_stat (filename_stamp1,   &statinfo[0]);
+  do_stat (filename_testfile, &statinfo[1]);
+  do_stat (filename_stamp2,   &statinfo[2]);
+  do_stat (filename_stamp3,   &statinfo[3]);
 
   /* Now use our access functions. */
   for (i = 0; i < NFILES; ++i)
@@ -160,7 +180,7 @@ test_ctime (const struct stat *statinfo)
   if (statinfo[0].st_mtime != statinfo[0].st_ctime)
     return;
 
-  /* mtime(stamp2) < ctime(renamed) */
+  /* mtime(stamp2) < ctime(testfile) */
   ASSERT (statinfo[2].st_mtime < statinfo[1].st_ctime
           || (statinfo[2].st_mtime == statinfo[1].st_ctime
               && (get_stat_mtime_ns (&statinfo[2])
@@ -183,11 +203,11 @@ test_birthtime (const struct stat *statinfo,
         return;
     }
 
-  /* mtime(stamp1) < birthtime(renamed) */
+  /* mtime(stamp1) < birthtime(testfile) */
   ASSERT (modtimes[0].tv_sec < birthtimes[1].tv_sec
           || (modtimes[0].tv_sec == birthtimes[1].tv_sec
               && modtimes[0].tv_nsec < birthtimes[1].tv_nsec));
-  /* birthtime(renamed) < mtime(stamp2) */
+  /* birthtime(testfile) < mtime(stamp2) */
   ASSERT (birthtimes[1].tv_sec < modtimes[2].tv_sec
           || (birthtimes[1].tv_sec == modtimes[2].tv_sec
               && birthtimes[1].tv_nsec < modtimes[2].tv_nsec));
@@ -200,6 +220,8 @@ main (void)
   struct timespec modtimes[NFILES];
   struct timespec birthtimes[NFILES];
 
+  initialize_filenames ();
+
 #ifdef SIGHUP
   signal (SIGHUP, cleanup);
 #endif


=================================== EXPERIMENT ==============================

$ gltests/test-stat-time.exe
i=0 modtime=1494769524.508897000 birthtime=1494769524.508897000
i=1 modtime=1494769524.509899300 birthtime=1494769524.509899300
i=2 modtime=1494769524.517378100 birthtime=1494769524.517378100
i=3 modtime=1494769524.535423400 birthtime=1494769524.535423400
File t-stt-stamp1: ret=0, st_ctim = 1494769524.508897000
File t-stt-testfile: ret=0, st_ctim = 1494769524.509899300
File t-stt-stamp2: ret=0, st_ctim = 1494769524.517378100
File t-stt-stamp3: ret=0, st_ctim = 1494769524.535423400

$ echo $?
0

$ gltests/test-stat-time.exe
File t-stt-stamp1: ret=0, st_ctim = 1494769524.508897000
File t-stt-testfile: ret=0, st_ctim = 1494769524.509899300
File t-stt-stamp2: ret=0, st_ctim = 1494769524.517378100
File t-stt-stamp3: ret=0, st_ctim = 1494769524.535423400
../../gltests/test-stat-time.c:193: assertion 'modtimes[0].tv_sec < 
birthtimes[1].tv_sec || (modtimes[0].tv_sec == birthtimes[1].tv_sec && 
modtimes[0].tv_nsec < birthtimes[1].tv_nsec)' failed

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
i=0 modtime=1494769535.271086600 birthtime=1494769524.508897000
i=1 modtime=1494769535.272055700 birthtime=1494769524.509899300
i=2 modtime=1494769535.275064100 birthtime=1494769524.517378100
i=3 modtime=1494769535.283084700 birthtime=1494769524.535423400

$ rm -f t-stt-*

$ gltests/test-stat-time.exe
File t-stt-stamp1: ret=0, st_ctim = 1494769524.508897000
File t-stt-testfile: ret=0, st_ctim = 1494769524.509899300
File t-stt-stamp2: ret=0, st_ctim = 1494769524.517378100
File t-stt-stamp3: ret=0, st_ctim = 1494769524.535423400
../../gltests/test-stat-time.c:193: assertion 'modtimes[0].tv_sec < 
birthtimes[1].tv_sec || (modtimes[0].tv_sec == birthtimes[1].tv_sec && 
modtimes[0].tv_nsec < birthtimes[1].tv_nsec)' failed

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
i=0 modtime=1494769595.727543200 birthtime=1494769524.508897000
i=1 modtime=1494769595.728546200 birthtime=1494769524.509899300
i=2 modtime=1494769595.731553900 birthtime=1494769524.517378100
i=3 modtime=1494769595.738220100 birthtime=1494769524.535423400