Hi Eric,
Great work, this testcase!
> If this invariant is not fulfilled and the stream is read-write but
> - currently writing, subsequent putc or fputc calls will write directly
> + currently reading, subsequent putc or fputc calls will write directly
> into the buffer, although they shouldn't be allowed to. */
Yes, the comment was wrong. Sorry if it led you the wrong way.
> + if test "$REPLACE_FPURGE$HAVE_DECL_FPURGE" != 01; then
> + AC_LIBOBJ([fpurge])
> + fi
This is not right: When REPLACE_FPURGE = 0 and HAVE_DECL_FPURGE = 0, it is not
needed to compile fpurge.c just because the declaration is missing. It would
also lead to a symbol clash, because in this case lib/stdio.in.h does not do
"#define fpurge rpl_fpurge", thus fpurge.o would and libc.so would both define
the symbol 'fpurge'. Which may lead to the expected effect of fpurge.o ends
up in a shared library that is dynamically loaded.
> + remove (TESTFILE);
Without a preceding fclose (fp), this call may not work on Windows platforms.
I'm applying this fix:
2009-08-16 Bruno Haible <br...@clisp.org>
* m4/fpurge.m4 (gl_FUNC_FPURGE): Don't compile fpurge.c if only the
declaration of fpurge is missing.
* tests/test-fpurge.c (main): Check that the file has not more contents
than expected. Close the file before removing it.
--- m4/fpurge.m4.orig 2009-08-16 14:43:16.000000000 +0200
+++ m4/fpurge.m4 2009-08-16 14:24:10.000000000 +0200
@@ -1,4 +1,4 @@
-# fpurge.m4 serial 4
+# fpurge.m4 serial 5
dnl Copyright (C) 2007, 2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -34,12 +34,10 @@
[gl_cv_func_fpurge_works='guessing no'])])
if test "x$gl_cv_func_fpurge_works" != xyes; then
REPLACE_FPURGE=1
+ AC_LIBOBJ([fpurge])
fi
fi
if test "x$ac_cv_have_decl_fpurge" = xno; then
HAVE_DECL_FPURGE=0
fi
- if test "$REPLACE_FPURGE$HAVE_DECL_FPURGE" != 01; then
- AC_LIBOBJ([fpurge])
- fi
])
--- tests/test-fpurge.c.orig 2009-08-16 14:43:16.000000000 +0200
+++ tests/test-fpurge.c 2009-08-16 14:42:28.000000000 +0200
@@ -51,6 +51,8 @@
if (fclose (fp))
goto skip;
+ /* The file's contents is now "foobarsh". */
+
/* Open it in read-write mode. */
fp = fopen (TESTFILE, "r+");
if (fp == NULL)
@@ -82,22 +84,30 @@
ASSERT (getc (fp) == EOF);
ASSERT (fclose (fp) == 0);
+ /* The file's contents is now "foogarsh". */
+
/* Ensure that purging a read does not corrupt subsequent writes. */
fp = fopen (TESTFILE, "r+");
- ASSERT (fp);
- ASSERT (fseek (fp, -1, SEEK_END) == 0);
+ if (fp == NULL)
+ goto skip;
+ if (fseek (fp, -1, SEEK_END))
+ goto skip;
ASSERT (getc (fp) == 'h');
ASSERT (getc (fp) == EOF);
ASSERT (fpurge (fp) == 0);
ASSERT (putc ('!', fp) == '!');
ASSERT (fclose (fp) == 0);
fp = fopen (TESTFILE, "r");
- ASSERT (fp);
+ if (fp == NULL)
+ goto skip;
{
- char buf[9];
- ASSERT (fread (buf, 1, 9, fp) == 9);
+ char buf[10];
+ ASSERT (fread (buf, 1, 10, fp) == 9);
ASSERT (memcmp (buf, "foogarsh!", 9) == 0);
}
+ ASSERT (fclose (fp) == 0);
+
+ /* The file's contents is now "foogarsh!". */
remove (TESTFILE);
return 0;
