* m4/putenv.m4 (gl_FUNC_PUTENV): Also mention that we're checking

[gnulib.git] / tests / test-freading.c

diff --git a/tests/test-freading.c b/tests/test-freading.c
index e51d7ab..d429a7c 100644 (file)
--- a/tests/test-freading.c
+++ b/tests/test-freading.c
@@ -1,10 +1,10 @@
 /* Test of freading() function.
    Copyright (C) 2007 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -12,8 +12,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
 
@@ -21,9 +20,19 @@
 
 #include "freading.h"
 
+#include <stdio.h>
 #include <stdlib.h>
 
-#define ASSERT(expr) if (!(expr)) abort ();
+#define ASSERT(expr) \
+  do                                                                        \
+    {                                                                       \
+      if (!(expr))                                                          \
+        {                                                                   \
+          fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
+          abort ();                                                         \
+        }                                                                   \
+    }                                                                       \
+  while (0)
 
 #define TESTFILE "t-freading.tmp"
 
@@ -73,6 +82,7 @@ main ()
      freading is only deterministic after input or output, but this
      test case should be portable even on open, after reposition, and
      at EOF.  */
+  /* First a scenario with only fgetc, fseek, fputc.  */
   fp = fopen (TESTFILE, "r+");
   if (fp == NULL)
     goto skip;
@@ -91,12 +101,14 @@ main ()
   if (fseek (fp, 0, SEEK_CUR) != 0)
     goto skip;
   /* freading (fp) is undefined here, but fwriting (fp) is false.  */
-  if (fputc ('z', fp) != 'z')
+  if (fputc ('x', fp) != 'x')
     goto skip;
   ASSERT (!freading (fp));
   if (fseek (fp, 0, SEEK_END))
     goto skip;
-  ASSERT (!freading (fp));
+  /* freading (fp) is undefined here, because on some implementations (e.g.
+     glibc) fseek causes a buffer to be read.
+     fwriting (fp) is undefined as well.  */
   if (fclose (fp))
     goto skip;
 
@@ -105,6 +117,7 @@ main ()
      freading is only deterministic after input or output, but this
      test case should be portable even on open, after reposition, and
      at EOF.  */
+  /* Here a scenario that includes fflush.  */
   fp = fopen (TESTFILE, "r+");
   if (fp == NULL)
     goto skip;
@@ -120,7 +133,7 @@ main ()
   ASSERT (freading (fp));
   fflush (fp);
   /* freading (fp) is undefined here, but fwriting (fp) is false.  */
-  if (fgetc (fp) != 'a')
+  if (fgetc (fp) != 'x')
     goto skip;
   ASSERT (freading (fp));
   /* This fseek call is necessary when switching from reading to writing.
@@ -133,7 +146,9 @@ main ()
   ASSERT (!freading (fp));
   if (fseek (fp, 0, SEEK_END))
     goto skip;
-  ASSERT (!freading (fp));
+  /* freading (fp) is undefined here, because on some implementations (e.g.
+     glibc) fseek causes a buffer to be read.
+     fwriting (fp) is undefined as well.  */
   if (fclose (fp))
     goto skip;