1 files changed, 137 insertions, 0 deletions
diff --git a/libc/libio/tst-mmap2-eofsync.c b/libc/libio/tst-mmap2-eofsync.c
new file mode 100644
index 000000000..f3699656a
--- /dev/null
+++ b/libc/libio/tst-mmap2-eofsync.c
@@ -0,0 +1,137 @@
+/* Test program for synchronization of stdio state with file after EOF.  */
+
+#include <stdio.h>
+#include <error.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+static void do_prepare (void);
+#define PREPARE(argc, argv) do_prepare ()
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include <test-skeleton.c>
+
+static char *temp_file;
+static int temp_fd;
+
+static char *pages;
+
+static void
+do_prepare (void)
+{
+  pages = malloc (getpagesize () * 2);
+  memset (pages, 'a', getpagesize ());
+  memset (pages + getpagesize (), 'b', getpagesize ());
+
+  temp_fd = create_temp_file ("tst-mmap2-eofsync.", &temp_file);
+  if (temp_fd == -1)
+    error (1, errno, "cannot create temporary file");
+  else
+    {
+      ssize_t cc = write (temp_fd, pages, getpagesize ());
+      if (cc != getpagesize ())
+	error (1, errno, "cannot write to temporary file");
+    }
+}
+
+static int
+do_test (void)
+{
+  const size_t pagesize = getpagesize ();
+  FILE *f;
+  char buf[pagesize];
+  int result = 0;
+  int c;
+
+  f = fopen (temp_file, "rm");
+  if (f == NULL)
+    {
+      perror (temp_file);
+      return 1;
+    }
+
+  if (fread (buf, pagesize, 1, f) != 1)
+    {
+      perror ("fread");
+      return 1;
+    }
+
+  if (memcmp (buf, pages, pagesize))
+    {
+      puts ("data mismatch in page 1");
+      result = 1;
+    }
+
+  printf ("feof = %d, ferror = %d immediately after fread\n",
+	  feof (f), ferror (f));
+
+  c = fgetc (f);
+  if (c == EOF)
+    printf ("fgetc -> EOF (feof = %d, ferror = %d)\n",
+	    feof (f), ferror (f));
+  else
+    {
+      printf ("fgetc returned %o (feof = %d, ferror = %d)\n",
+	      c, feof (f), ferror (f));
+      result = 1;
+    }
+
+  c = write (temp_fd, pages + pagesize, pagesize);
+  if (c == (ssize_t) pagesize)
+    printf ("wrote more to file\n");
+  else
+    {
+      printf ("wrote %d != %zd (%m)\n", c, pagesize);
+      result = 1;
+    }
+
+  if (fread (buf, pagesize, 1, f) != 1)
+    {
+      printf ("second fread fails: feof = %d, ferror = %d (%m)\n",
+	      feof (f), ferror (f));
+      clearerr (f);
+      if (fread (buf, pagesize, 1, f) != 1)
+	{
+	  printf ("retry fread fails: feof = %d, ferror = %d (%m)\n",
+		  feof (f), ferror (f));
+	  result = 1;
+	}
+    }
+  if (result == 0 && memcmp (buf, pages + pagesize, pagesize))
+    {
+      puts ("data mismatch in page 2");
+      result = 1;
+    }
+
+  fseek (f, pagesize - 1, SEEK_SET);
+  c = fgetc (f);
+  if (c != 'a')
+    {
+      printf ("fgetc at end of page 1 read '%c' (%m)\n", c);
+      result = 1;
+    }
+
+  if (ftruncate (temp_fd, pagesize) < 0)
+    {
+      printf ("ftruncate failed: %m\n");
+      result = 1;
+    }
+
+  fflush (f);
+
+  c = fgetc (f);
+  if (c == EOF)
+    printf ("after truncate fgetc -> EOF (feof = %d, ferror = %d)\n",
+	    feof (f), ferror (f));
+  else
+    {
+      printf ("after truncate fgetc returned '%c' (feof = %d, ferror = %d)\n",
+	      c, feof (f), ferror (f));
+      result = 1;
+    }
+
+  fclose (f);
+
+  return result;
+}