path: root/0001-Use-CreateFile-on-Win32-to-make-sure-g_unlink-always.patch

From 7f4f4354540440c0a8a37beaccbec8bc7fc15ec7 Mon Sep 17 00:00:00 2001
From: Erik van Pienbroek <epienbro@fedoraproject.org>
Date: Mon, 27 Aug 2012 23:28:54 +0200
Subject: [PATCH] Use CreateFile on Win32 to make sure g_unlink always works

The functions g_open(), g_creat() and g_fopen() defer to _wopen(),
_wcreat() and _wfopen() respectively. This is very similar to
the corresponding arrangement for Linux. However, those Windows
functions do not support renaming a file whilst it's open. As a
result, g_rename() behaves differently on the Windows platform
compared to its Linux behaviour, where files can be renamed even
while there are file handles still open. Resolved this by using
the Win32 API function CreateFile() instead of _wopen(), _wcreat()
and _wfopen()

Patch initially created by John Emmas
---
 glib/gstdio.c | 259 ++++++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 233 insertions(+), 26 deletions(-)

diff --git a/glib/gstdio.c b/glib/gstdio.c
index 6d763e1..c1d072f 100644
--- a/glib/gstdio.c
+++ b/glib/gstdio.c
@@ -758,6 +758,11 @@
 	int          mode)
 {
 #ifdef G_OS_WIN32
+  HANDLE hFile;
+  DWORD  dwDesiredAccess       = 0;
+  DWORD  dwFlagsAndAttributes  = 0;
+  DWORD  dwDisposition         = OPEN_EXISTING;
+  DWORD  dwSharedAccess        = FILE_SHARE_READ | FILE_SHARE_DELETE;
   wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
   int retval;
   int save_errno;
@@ -768,12 +773,114 @@
       return -1;
     }
 
-  retval = _wopen (wfilename, flags, mode);
-  save_errno = errno;
+  /* Set up the access modes and other attributes */
+  if ((flags & _O_CREAT) && (mode & _S_IREAD))
+  {
+    if (! (mode & _S_IWRITE))
+      dwFlagsAndAttributes  = FILE_ATTRIBUTE_READONLY; /* Sets file to 'read only' after the file gets closed */
+  }
+  if ( !(flags & _O_ACCMODE))
+  {
+    /* Equates to _O_RDONLY */
+    if (flags & _O_TRUNC)
+	{
+	  errno = EINVAL;
+	  g_free (wfilename);
+	  return -1;
+	}
 
-  g_free (wfilename);
+	dwDesiredAccess |= GENERIC_READ;
+	dwSharedAccess  |= FILE_SHARE_WRITE;
+  }
+  if (flags & _O_WRONLY)
+  {
+    if (flags & _O_RDWR)
+	{
+	  errno = EINVAL;
+	  g_free (wfilename);
+	  return -1;
+	}
+
+	dwDesiredAccess |= GENERIC_WRITE;
+  }
+  if (flags & _O_RDWR)
+  {
+	dwDesiredAccess |= GENERIC_READ;
+	dwDesiredAccess |= GENERIC_WRITE;
+  }
+  if (flags & _O_TRUNC)
+  {
+    if (flags & _O_CREAT)
+	  dwDisposition = CREATE_ALWAYS;
+	else
+	  dwDisposition = TRUNCATE_EXISTING;
+  }
+  if ((flags & _O_CREAT) && !(flags & _O_TRUNC))
+  {
+    if (flags & _O_EXCL)
+	  dwDisposition = CREATE_NEW;
+	else
+	  dwDisposition = OPEN_ALWAYS;
+  }
+  if (flags & _O_CREAT)
+  {
+    /* Handle the other flags that can be attached to _O_CREAT */
+    if ((flags & _O_TEMPORARY) || (flags & _O_SHORT_LIVED))
+      dwFlagsAndAttributes |= FILE_ATTRIBUTE_TEMPORARY;
+
+    if (flags & _O_TEMPORARY)
+      dwFlagsAndAttributes |= FILE_FLAG_DELETE_ON_CLOSE;
+  }
+  if ((flags & _O_SEQUENTIAL) || (flags & _O_APPEND))
+  {
+    dwFlagsAndAttributes |= FILE_FLAG_SEQUENTIAL_SCAN;
+  }
+  else if (flags & _O_RANDOM)
+  {
+    dwFlagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;
+  }
+
+  if (0 == dwFlagsAndAttributes)
+    dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
+  hFile = CreateFileW(wfilename, dwDesiredAccess, dwSharedAccess, NULL, dwDisposition, dwFlagsAndAttributes, NULL);
+
+  if (INVALID_HANDLE_VALUE == hFile)
+  {
+    retval = (-1);
+
+    switch (GetLastError ())
+    {
+#define CASE(a,b) case ERROR_##a: errno = b; break
+      CASE (FILE_NOT_FOUND, ENOENT);
+      CASE (PATH_NOT_FOUND, ENOENT);
+      CASE (ACCESS_DENIED, EACCES);
+      CASE (NOT_SAME_DEVICE, EXDEV);
+      CASE (LOCK_VIOLATION, EACCES);
+      CASE (SHARING_VIOLATION, EACCES);
+      CASE (FILE_EXISTS, EEXIST);
+      CASE (ALREADY_EXISTS, EEXIST);
+#undef CASE
+      default: errno = EIO;
+    }
+  }
+  else
+    retval = _open_osfhandle((long)hFile, flags);
 
+  if ((-1) != retval)
+  {
+    /* We have a valid file handle. Set its translation mode to text or binary, as appropriate */
+    if ((!(flags & _O_TEXT)) && (_fmode == _O_BINARY))
+      _setmode(retval, _O_BINARY);
+    else if ((flags & _O_TEXT) || (_fmode == _O_TEXT))
+      _setmode(retval, _O_TEXT);
+    else
+      _setmode(retval, _O_BINARY);
+  }
+
+  save_errno = errno;
+  g_free (wfilename);
   errno = save_errno;
+
   return retval;
 #else
   int fd;
@@ -821,6 +928,8 @@
 	 int          mode)
 {
 #ifdef G_OS_WIN32
+  HANDLE hFile;
+  DWORD  dwFlagsAndAttributes  = FILE_ATTRIBUTE_NORMAL;
   wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
   int retval;
   int save_errno;
@@ -831,12 +940,41 @@
       return -1;
     }
 
-  retval = _wcreat (wfilename, mode);
-  save_errno = errno;
+  if (mode & _S_IREAD)
+  {
+    if (! (mode & _S_IWRITE))
+      dwFlagsAndAttributes  = FILE_ATTRIBUTE_READONLY; /* Sets file to 'read only' after the file gets closed */
+  }
+
+  hFile = CreateFileW(wfilename, (GENERIC_READ | GENERIC_WRITE), (FILE_SHARE_READ | FILE_SHARE_DELETE),
+                                  NULL, CREATE_ALWAYS, dwFlagsAndAttributes, NULL);
+
+  if (INVALID_HANDLE_VALUE == hFile)
+  {
+    retval = (-1);
+
+    switch (GetLastError ())
+    {
+#define CASE(a,b) case ERROR_##a: errno = b; break
+      CASE (FILE_NOT_FOUND, ENOENT);
+      CASE (PATH_NOT_FOUND, ENOENT);
+      CASE (ACCESS_DENIED, EACCES);
+      CASE (NOT_SAME_DEVICE, EXDEV);
+      CASE (LOCK_VIOLATION, EACCES);
+      CASE (SHARING_VIOLATION, EACCES);
+      CASE (FILE_EXISTS, EEXIST);
+      CASE (ALREADY_EXISTS, EEXIST);
+#undef CASE
+      default: errno = EIO;
+    }
+  }
+  else
+    retval = _open_osfhandle((long)hFile, _O_RDWR);
 
+  save_errno = errno;
   g_free (wfilename);
-
   errno = save_errno;
+
   return retval;
 #else
   return creat (filename, mode);
@@ -1286,36 +1424,102 @@
 	 const gchar *mode)
 {
 #ifdef G_OS_WIN32
-  wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
-  wchar_t *wmode;
-  gchar   *mode2;
-  FILE *retval;
-  int save_errno;
-
-  if (wfilename == NULL)
-    {
-      errno = EINVAL;
-      return NULL;
-    }
-
-  mode2 = _g_win32_get_mode_alias (mode);
-  wmode = g_utf8_to_utf16 (mode2, -1, NULL, NULL, NULL);
-  g_free (mode2);
-
-  if (wmode == NULL)
-    {
-      g_free (wfilename);
-      errno = EINVAL;
-      return NULL;
-    }
+  int   hFile;
+  int   flags  = 0;
+  gchar priv_mode[4];
+  FILE *retval = NULL;
+
+  if ((NULL == filename) || (NULL == mode))
+  {
+    errno = EINVAL;
+    goto out;
+  }
+  if ((strlen(mode) < 1) || (strlen(mode) > 3))
+  {
+    errno - EINVAL;
+    goto out;
+  }
+
+  strncpy(priv_mode, mode, 3);
+  priv_mode[3] = '\0';
+
+  /* Set up any flags to pass to 'g_open()' */
+  if (3 == strlen(priv_mode))
+  {
+    if (('c' == priv_mode[2]) || ('n' == priv_mode[2]))
+      priv_mode[2] = '\0';
+    else
+    {
+      if (0 == strcmp(priv_mode, "a+b"))
+        flags = _O_RDWR | _O_CREAT | _O_APPEND | _O_BINARY;
+      else if (0 == strcmp(priv_mode, "a+t"))
+        flags = _O_RDWR | _O_CREAT | _O_APPEND | _O_TEXT;
+      else if (0 == strcmp(priv_mode, "r+b"))
+        flags = _O_RDWR | _O_BINARY;
+      else if (0 == strcmp(priv_mode, "r+t"))
+        flags = _O_RDWR | _O_TEXT;
+      else if (0 == strcmp(priv_mode, "w+b"))
+        flags = _O_RDWR | _O_CREAT |_O_TRUNC | _O_BINARY;
+      else if (0 == strcmp(priv_mode, "w+t"))
+        flags = _O_RDWR | _O_CREAT |_O_TRUNC | _O_TEXT;
+      else
+	  {
+	    errno = EINVAL;
+        goto out;
+	  }
+    }
+  }
+  if (2 == strlen(priv_mode))
+  {
+    if (('c' == priv_mode[1]) || ('n' == priv_mode[1]))
+      priv_mode[1] = '\0';
+    else
+    {
+      if (0 == strcmp(priv_mode, "a+"))
+        flags = _O_RDWR | _O_CREAT | _O_APPEND;
+      else if (0 == strcmp(priv_mode, "ab"))
+        flags = _O_WRONLY | _O_CREAT | _O_APPEND | _O_BINARY;
+      else if (0 == strcmp(priv_mode, "at"))
+        flags = _O_WRONLY | _O_CREAT | _O_APPEND | _O_TEXT;
+      else if (0 == strcmp(priv_mode, "rb"))
+        flags = _O_RDONLY | _O_BINARY;
+      else if (0 == strcmp(priv_mode, "rt"))
+        flags = _O_RDONLY | _O_TEXT;
+      else if (0 == strcmp(priv_mode, "wb"))
+        flags = _O_WRONLY | _O_CREAT | _O_TRUNC | _O_BINARY;
+      else if (0 == strcmp(priv_mode, "wt"))
+        flags = _O_WRONLY | _O_CREAT | _O_TRUNC | _O_TEXT;
+      else
+	  {
+	    errno = EINVAL;
+        goto out;
+	  }
+    }
+  }
+  if (1 == strlen(priv_mode))
+  {
+    if (0 == strcmp(priv_mode, "a"))
+      flags = _O_WRONLY | _O_CREAT | _O_APPEND;
+    else if (0 == strcmp(priv_mode, "r"))
+      flags = _O_RDONLY;
+    else if (0 == strcmp(priv_mode, "w"))
+      flags = _O_WRONLY | _O_CREAT | _O_TRUNC;
+    else if ( !((0 == strcmp(priv_mode, "c")) || (0 == strcmp(priv_mode, "n"))))
+	{
+	  errno = EINVAL;
+      goto out;
+	}
+  }
 
-  retval = _wfopen (wfilename, wmode);
-  save_errno = errno;
+  hFile = g_open (filename, flags, (_S_IREAD | _S_IWRITE));
 
-  g_free (wfilename);
-  g_free (wmode);
+  if (INVALID_HANDLE_VALUE == (HANDLE)hFile)
+    /* 'errno' will have already been set by 'g_open()' */
+    retval = NULL;
+  else
+    retval = _fdopen(hFile, mode);
 
-  errno = save_errno;
+out:
   return retval;
 #else
   return fopen (filename, mode);