2006-03-07 Eric Blake <ebb9@byu.net>

        * libc/stdio/freopen.c (_freopen_r) [HAVE_FCNTL]: For NULL
        filename, allow read-only or write-only FILE atop O_RDWR file
        descriptor.
        * libc/stdio64/freopen64.c (_freopen64_r) [HAVE_FCNTL]: Likewise.

diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index 5b7f21b..552742b 100644 (file)
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,10 @@
+2006-03-07  Eric Blake  <ebb9@byu.net>
+
+       * libc/stdio/freopen.c (_freopen_r) [HAVE_FCNTL]: For NULL
+       filename, allow read-only or write-only FILE atop O_RDWR file
+       descriptor.
+       * libc/stdio64/freopen64.c (_freopen64_r) [HAVE_FCNTL]: Likewise.
+
 2006-03-07  Jeff Johnston  <jjohnstn@redhat.com>
 
        * libm/common/sf_isinf.c[_DOUBLE_IS_32BITS]: Undef isinf.

diff --git a/newlib/libc/stdio/freopen.c b/newlib/libc/stdio/freopen.c
index d5582d4..ae3444b 100644 (file)
--- a/newlib/libc/stdio/freopen.c
+++ b/newlib/libc/stdio/freopen.c
@@ -56,10 +56,10 @@ it).
 <[file]> and <[mode]> are used just as in <<fopen>>.
 
 If <[file]> is <<NULL>>, the underlying stream is modified rather than
-closed.  The file cannot change access mode (for example, if it was
-previously read-only, <[mode]> must be "r", "rb", or "rt"), but can
-change status such as append or binary mode.  If modification is not
-possible, failure occurs.
+closed.  The file cannot be given a more permissive access mode (for
+example, a <[mode]> of "w" will fail on a read-only file descriptor),
+but can change status such as append or binary mode.  If modification
+is not possible, failure occurs.
 
 RETURNS
 If successful, the result is the same as the argument <[fp]>.  If the
@@ -148,12 +148,14 @@ _DEFUN(_freopen_r, (ptr, file, mode, fp),
 #ifdef HAVE_FCNTL
       int oldflags;
       /*
-       * Reuse the file descriptor, but only if the access mode is
-       * unchanged.  F_SETFL correctly ignores creation flags.
+       * Reuse the file descriptor, but only if the new access mode is
+       * equal or less permissive than the old.  F_SETFL correctly
+       * ignores creation flags.
        */
       f = fp->_file;
       if ((oldflags = _fcntl_r (ptr, f, F_GETFL, 0)) == -1
-          || ((oldflags ^ oflags) & O_ACCMODE) != 0
+          || ! ((oldflags & O_ACCMODE) == O_RDWR
+                || ((oldflags ^ oflags) & O_ACCMODE) == 0)
           || _fcntl_r (ptr, f, F_SETFL, oflags) == -1)
         f = -1;
 #else

diff --git a/newlib/libc/stdio64/freopen64.c b/newlib/libc/stdio64/freopen64.c
index 8acb957..6081e03 100644 (file)
--- a/newlib/libc/stdio64/freopen64.c
+++ b/newlib/libc/stdio64/freopen64.c
@@ -56,10 +56,10 @@ it).
 <[file]> and <[mode]> are used just as in <<fopen>>.
 
 If <[file]> is <<NULL>>, the underlying stream is modified rather than
-closed.  The file cannot change access mode (for example, if it was
-previously read-only, <[mode]> must be "r", "rb", or "rt"), but can
-change status such as append or binary mode.  If modification is not
-possible, failure occurs.
+closed.  The file cannot be given a more permissive access mode (for
+example, a <[mode]> of "w" will fail on a read-only file descriptor),
+but can change status such as append or binary mode.  If modification
+is not possible, failure occurs.
 
 RETURNS
 If successful, the result is the same as the argument <[fp]>.  If the
@@ -148,12 +148,14 @@ _DEFUN (_freopen64_r, (ptr, file, mode, fp),
 #ifdef HAVE_FCNTL
       int oldflags;
       /*
-       * Reuse the file descriptor, but only if the access mode is
-       * unchanged.  F_SETFL correctly ignores creation flags.
+       * Reuse the file descriptor, but only if the new access mode is
+       * equal or less permissive than the old.  F_SETFL correctly
+       * ignores creation flags.
        */
       f = fp->_file;
       if ((oldflags = _fcntl_r (ptr, f, F_GETFL, 0)) == -1
-          || ((oldflags ^ oflags) & O_ACCMODE) != 0
+          || ! ((oldflags & O_ACCMODE) == O_RDWR
+                || ((oldflags ^ oflags) & O_ACCMODE) == 0)
           || _fcntl_r (ptr, f, F_SETFL, oflags) == -1)
         f = -1;
 #else