From e34c756b945fd7970875fd42e81e636fe5dbd247 Mon Sep 17 00:00:00 2001
From: solar <unknown>
Date: Sat, 20 Nov 2010 06:01:42 +0000
Subject: [PATCH] Bug #39: fclose( stdout ) corrupts memory

---
 functions/stdio/fclose.c                     | 6 ++++--
 internals/_PDCLIB_int.h                      | 8 ++++++++
 platform/example/functions/_PDCLIB/stdinit.c | 6 +++---
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/functions/stdio/fclose.c b/functions/stdio/fclose.c
index 2b68694..5c1e4d4 100644
--- a/functions/stdio/fclose.c
+++ b/functions/stdio/fclose.c
@@ -49,8 +49,10 @@ int fclose( struct _PDCLIB_file_t * stream )
                 remove( stream->filename );
             }
             /* Free stream */
-            free( stream );
-
+            if ( ! stream->status & _PDCLIB_STATIC )
+            {
+                free( stream );
+            }
             return 0;
         }
         previous = current;
diff --git a/internals/_PDCLIB_int.h b/internals/_PDCLIB_int.h
index a4cf38b..0bad643 100644
--- a/internals/_PDCLIB_int.h
+++ b/internals/_PDCLIB_int.h
@@ -268,12 +268,20 @@ typedef unsigned _PDCLIB_intmax _PDCLIB_uintmax_t;
 #define _PDCLIB_FBIN    128u
 
 /* Internal flags, made to fit the same status field as the flags above. */
+/* -------------------------------------------------------------------------- */
+/* free() the buffer memory on closing (false for user-supplied buffer) */
 #define _PDCLIB_FREEBUFFER   512u
+/* stream has encountered error / EOF */
 #define _PDCLIB_ERRORFLAG   1024u
 #define _PDCLIB_EOFFLAG     2048u
+/* stream is wide-oriented */
 #define _PDCLIB_WIDESTREAM  4096u
+/* stream is byte-oriented */
 #define _PDCLIB_BYTESTREAM  8192u
+/* file associated with stream should be remove()d on closing (tmpfile()) */
 #define _PDCLIB_DELONCLOSE 16384u
+/* stream handle should not be free()d on close (stdin, stdout, stderr) */
+#define _PDCLIB_STATIC     32768u
 
 /* Position / status structure for getpos() / fsetpos(). */
 struct _PDCLIB_fpos_t
diff --git a/platform/example/functions/_PDCLIB/stdinit.c b/platform/example/functions/_PDCLIB/stdinit.c
index 78c76e2..8ddb774 100644
--- a/platform/example/functions/_PDCLIB/stdinit.c
+++ b/platform/example/functions/_PDCLIB/stdinit.c
@@ -27,9 +27,9 @@ static unsigned char _PDCLIB_sin_ungetbuf[_PDCLIB_UNGETCBUFSIZE];
 static unsigned char _PDCLIB_sout_ungetbuf[_PDCLIB_UNGETCBUFSIZE];
 static unsigned char _PDCLIB_serr_ungetbuf[_PDCLIB_UNGETCBUFSIZE];
 
-static struct _PDCLIB_file_t _PDCLIB_serr = { 2, _PDCLIB_serr_buffer, BUFSIZ, 0, 0, { 0, 0 }, 0, _PDCLIB_serr_ungetbuf, _IONBF | _PDCLIB_FWRITE, NULL, NULL };
-static struct _PDCLIB_file_t _PDCLIB_sout = { 1, _PDCLIB_sout_buffer, BUFSIZ, 0, 0, { 0, 0 }, 0, _PDCLIB_sout_ungetbuf, _IOLBF | _PDCLIB_FWRITE, NULL, &_PDCLIB_serr };
-static struct _PDCLIB_file_t _PDCLIB_sin  = { 0, _PDCLIB_sin_buffer, BUFSIZ, 0, 0, { 0, 0 }, 0, _PDCLIB_sin_ungetbuf, _IOLBF | _PDCLIB_FREAD, NULL, &_PDCLIB_sout };
+static struct _PDCLIB_file_t _PDCLIB_serr = { 2, _PDCLIB_serr_buffer, BUFSIZ, 0, 0, { 0, 0 }, 0, _PDCLIB_serr_ungetbuf, _IONBF | _PDCLIB_FWRITE | _PDCLIB_STATIC, NULL, NULL };
+static struct _PDCLIB_file_t _PDCLIB_sout = { 1, _PDCLIB_sout_buffer, BUFSIZ, 0, 0, { 0, 0 }, 0, _PDCLIB_sout_ungetbuf, _IOLBF | _PDCLIB_FWRITE | _PDCLIB_STATIC, NULL, &_PDCLIB_serr };
+static struct _PDCLIB_file_t _PDCLIB_sin  = { 0, _PDCLIB_sin_buffer, BUFSIZ, 0, 0, { 0, 0 }, 0, _PDCLIB_sin_ungetbuf, _IOLBF | _PDCLIB_FREAD | _PDCLIB_STATIC, NULL, &_PDCLIB_sout };
 
 struct _PDCLIB_file_t * stdin  = &_PDCLIB_sin;
 struct _PDCLIB_file_t * stdout = &_PDCLIB_sout;
-- 
2.40.0