Implement a win32 tmpfile() function

Bug report and proposed patch at:
http://lists.cairographics.org/archives/cairo/2007-December/012529.html

On Windows the tmpfile() function creates the file in the root
directory. This will fail if the user does not have write access to the
root directory.

Implement _cairo_win32_tmpfile() that is #defined as tmpfile() on
Windows. This function uses GetTempPath() and GetTempFileName() to
create the temporary file. CreateFile() is used to open the file so
the DELETE_ON_CLOSE flag can be set.

src/Makefile.am

@@ -73,12 +73,13 @@ libcairo_quartz_sources = cairo-quartz-surface.c cairo-quartz-private.h
 backend_pkgconfigs += cairo-quartz.pc
 endif
 
+libcairo_win32_sources =
 if OS_WIN32
+libcairo_win32_sources += cairo-win32.c
 export_symbols = -export-symbols cairo.def
 cairo_def_dependency = cairo.def
 endif
 
-libcairo_win32_sources =
 if CAIRO_HAS_WIN32_SURFACE
 libcairo_win32_headers = cairo-win32.h
 libcairo_win32_sources += cairo-win32-surface.c cairo-win32-printing-surface.c cairo-win32-private.h

src/cairo-win32.c

@@ -0,0 +1,98 @@
+/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
+/* Cairo - a vector graphics library with display and print output
+ *
+ * Copyright © 2007 Adrian Johnson
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ *
+ * The Original Code is the cairo graphics library.
+ *
+ * The Initial Developer of the Original Code is Adrian Johnson.
+ *
+ * Contributor(s):
+ *      Adrian Johnson <ajohnson@redneon.com>
+ */
+
+#define WIN32_LEAN_AND_MEAN
+/* We require Windows 2000 features such as ETO_PDY */
+#if !defined(WINVER) || (WINVER < 0x0500)
+# define WINVER 0x0500
+#endif
+#if !defined(_WIN32_WINNT) || (_WIN32_WINNT < 0x0500)
+# define _WIN32_WINNT 0x0500
+#endif
+
+#include "cairoint.h"
+
+#include <windows.h>
+#include <io.h>
+
+/* tmpfile() replacment for Windows.
+ *
+ * On Windows tmpfile() creates the file in the root directory. This
+ * may fail due to unsufficient privileges.
+ */
+FILE *
+_cairo_win32_tmpfile (void)
+{
+    DWORD path_len;
+    WCHAR path_name[MAX_PATH + 1];
+    WCHAR file_name[MAX_PATH + 1];
+    HANDLE handle;
+    int fd;
+    FILE *fp;
+
+    path_len = GetTempPathW (MAX_PATH, path_name);
+    if (path_len <= 0 || path_len >= MAX_PATH)
+	return NULL;
+
+    if (GetTempFileNameW (path_name, L"ps_", 0, file_name) == 0)
+	return NULL;
+
+    handle = CreateFileW (file_name,
+			 GENERIC_READ | GENERIC_WRITE,
+			 0,
+			 NULL,
+			 CREATE_ALWAYS,
+			 FILE_ATTRIBUTE_NORMAL | FILE_FLAG_DELETE_ON_CLOSE,
+			 NULL);
+    if (handle == INVALID_HANDLE_VALUE) {
+	DeleteFileW (file_name);
+	return NULL;
+    }
+
+    fd = _open_osfhandle((intptr_t) handle, 0);
+    if (fd < 0) {
+	CloseHandle (handle);
+	return NULL;
+    }
+
+    fp = fdopen(fd, "w+b");
+    if (fp == NULL) {
+	_close(fd);
+	return NULL;
+    }
+
+    return fp;
+}

src/cairoint.h

@@ -81,6 +81,12 @@
 
 CAIRO_BEGIN_DECLS
 
+#ifdef _WIN32
+cairo_private FILE *
+_cairo_win32_tmpfile (void);
+#define tmpfile() _cairo_win32_tmpfile()
+#endif
+
 #undef MIN
 #define MIN(a, b) ((a) < (b) ? (a) : (b))