fclose on MSVC

[Bruno Haible]

On MSVC 9, it's the code from lib/fclose.c which makes fclose(stdout) crash:

  if (close (fd) < 0 && saved_errno == 0)
    saved_errno = errno;
    
  fclose (fp); /* will fail with errno = EBADF, if we did not lose a race */


Here's the fix.


2011-09-25  Bruno Haible  <address@hidden>

        fclose: Support for MSVC 9.
        * lib/fclose.c: Include msvc-inval.h.
        (fclose_nothrow): New function.
        (rpl_fclose): Use it.
        * modules/fclose (Depends-on): Add msvc-inval.
        * doc/posix-functions/fclose.texi: Mention the problem on MSVC.

--- doc/posix-functions/fclose.texi.orig        Sun Sep 25 12:04:17 2011
+++ doc/posix-functions/fclose.texi     Sun Sep 25 11:57:54 2011
@@ -13,6 +13,10 @@
 seekable input stream to the byte after the last one actually read:
 glibc 2.13, FreeBSD.
 @item
+This function crashes if the stream's file descriptor has already been
+closed on some platforms:
+MSVC 9.
address@hidden
 On Windows platforms (excluding Cygwin), @code{socket} and @code{accept}
 followed by @code{fdopen} do not return streams that can be closed by
 @code{fclose}.
--- lib/fclose.c.orig   Sun Sep 25 12:04:17 2011
+++ lib/fclose.c        Sun Sep 25 12:00:47 2011
@@ -23,12 +23,37 @@
 #include <unistd.h>
 
 #include "freading.h"
+#include "msvc-inval.h"
+
+#undef fclose
+
+#if HAVE_MSVC_INVALID_PARAMETER_HANDLER
+static int
+fclose_nothrow (FILE *fp)
+{
+  int result;
+
+  TRY_MSVC_INVAL
+    {
+      result = fclose (fp);
+    }
+  CATCH_MSVC_INVAL
+    {
+      result = EOF;
+      errno = EBADF;
+    }
+  DONE_MSVC_INVAL;
+
+  return result;
+}
+#else
+# define fclose_nothrow fclose
+#endif
 
 /* Override fclose() to call the overridden fflush() or close().  */
 
 int
 rpl_fclose (FILE *fp)
-#undef fclose
 {
   int saved_errno = 0;
   int fd;
@@ -37,7 +62,7 @@
   /* Don't change behavior on memstreams.  */
   fd = fileno (fp);
   if (fd < 0)
-    return fclose (fp);
+    return fclose_nothrow (fp);
 
   /* We only need to flush the file if it is not reading or if it is
      seekable.  This only guarantees the file position of input files
@@ -55,7 +80,8 @@
   if (close (fd) < 0 && saved_errno == 0)
     saved_errno = errno;
 
-  fclose (fp); /* will fail with errno = EBADF, if we did not lose a race */
+  fclose_nothrow (fp); /* will fail with errno = EBADF,
+                          if we did not lose a race */
 
 #else /* !WINDOWS_SOCKETS */
   /* Call fclose() and invoke all hooks of the overridden close().  */
@@ -64,12 +90,12 @@
   /* Note about multithread-safety: There is a race condition here as well.
      Some other thread could open fd between our calls to fclose and
      _gl_unregister_fd.  */
-  result = fclose (fp);
+  result = fclose_nothrow (fp);
   if (result == 0)
     _gl_unregister_fd (fd);
 # else
   /* No race condition here.  */
-  result = fclose (fp);
+  result = fclose_nothrow (fp);
 # endif
 
 #endif /* !WINDOWS_SOCKETS */
--- modules/fclose.orig Sun Sep 25 12:04:17 2011
+++ modules/fclose      Sun Sep 25 12:01:21 2011
@@ -11,6 +11,7 @@
 fflush          [test $REPLACE_FCLOSE = 1]
 freading        [test $REPLACE_FCLOSE = 1]
 lseek           [test $REPLACE_FCLOSE = 1]
+msvc-inval      [test $REPLACE_FCLOSE = 1]
 
 configure.ac:
 gl_FUNC_FCLOSE
-- 
In memoriam Safia Ahmed-jan <http://en.wikipedia.org/wiki/Safia_Ahmed-jan>