From e44ca1c085b3bd41266c882ea1cb0fd436231635 Mon Sep 17 00:00:00 2001
From: Joseph Myers <josmyers@redhat.com>
Date: Thu, 5 Sep 2024 20:08:10 +0000
Subject: [PATCH] Fix freopen handling of ,ccs= (bug 23675)

As reported in bug 23675 and shown up in the recently added tests of
different cases of freopen (relevant part of the test currently
conditioned under #if 0 to avoid a failure resulting from this bug),
freopen wrongly forces the stream to unoriented even when a mode with
,ccs= is specified, though such a mode is supposed to result in a
wide-oriented stream.  Move the clearing of _mode to before the actual
reopening occurs, so that the main fopen implementation can leave a
wide-oriented stream in the ,ccs= case.

Tested for x86_64.
---
 libio/freopen.c                  | 5 ++---
 libio/freopen64.c                | 4 +---
 stdio-common/tst-freopen2-main.c | 5 -----
 3 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/libio/freopen.c b/libio/freopen.c
index ceeff8f2ac..00f26ad578 100644
--- a/libio/freopen.c
+++ b/libio/freopen.c
@@ -66,6 +66,7 @@ freopen (const char *filename, const char *mode, FILE *fp)
       fp->_flags2 &= ~(_IO_FLAGS2_MMAP
 		       | _IO_FLAGS2_NOTCANCEL
 		       | _IO_FLAGS2_CLOEXEC);
+      fp->_mode = 0;
       result = _IO_old_file_fopen (fp, gfilename, mode);
     }
   else
@@ -78,6 +79,7 @@ freopen (const char *filename, const char *mode, FILE *fp)
       fp->_flags2 &= ~(_IO_FLAGS2_MMAP
 		       | _IO_FLAGS2_NOTCANCEL
 		       | _IO_FLAGS2_CLOEXEC);
+      fp->_mode = 0;
       result = _IO_file_fopen (fp, gfilename, mode, 1);
       if (result != NULL)
 	result = __fopen_maybe_mmap (result);
@@ -85,9 +87,6 @@ freopen (const char *filename, const char *mode, FILE *fp)
   fp->_flags2 &= ~_IO_FLAGS2_NOCLOSE;
   if (result != NULL)
     {
-      /* unbound stream orientation */
-      result->_mode = 0;
-
       if (fd != -1 && _IO_fileno (result) != fd)
 	{
 	  /* At this point we have both file descriptors already allocated,
diff --git a/libio/freopen64.c b/libio/freopen64.c
index 3a314aca5c..77c0dd3fdf 100644
--- a/libio/freopen64.c
+++ b/libio/freopen64.c
@@ -59,15 +59,13 @@ freopen64 (const char *filename, const char *mode, FILE *fp)
   fp->_flags2 &= ~(_IO_FLAGS2_MMAP
 		   | _IO_FLAGS2_NOTCANCEL
 		   | _IO_FLAGS2_CLOEXEC);
+  fp->_mode = 0;
   result = _IO_file_fopen (fp, gfilename, mode, 0);
   fp->_flags2 &= ~_IO_FLAGS2_NOCLOSE;
   if (result != NULL)
     result = __fopen_maybe_mmap (result);
   if (result != NULL)
     {
-      /* unbound stream orientation */
-      result->_mode = 0;
-
       if (fd != -1 && _IO_fileno (result) != fd)
 	{
 	  /* At this point we have both file descriptors already allocated,
diff --git a/stdio-common/tst-freopen2-main.c b/stdio-common/tst-freopen2-main.c
index 5dad41c76b..74c3125fca 100644
--- a/stdio-common/tst-freopen2-main.c
+++ b/stdio-common/tst-freopen2-main.c
@@ -386,13 +386,8 @@ do_test (void)
   fp = xfopen (file2, "w,ccs=iso-8859-1");
   ret = fputws (L"\xc0\xc1", fp);
   TEST_VERIFY (ret >= 0);
-#if 0 /* Doesn't work (bug 23675).  */
   fp = FREOPEN (file1, "r,ccs=utf-8", fp);
   TEST_VERIFY_EXIT (fp != NULL);
-#else /* Works instead.  */
-  xfclose (fp);
-  fp = xfopen (file1, "r,ccs=utf-8");
-#endif
   wc = fgetwc (fp);
   TEST_COMPARE (wc, (wint_t) 0xc0);
   wc = fgetwc (fp);