SetEndOfFile fix

[Rein Klazes]

hi,

This fixes office 97 MSword error (disk full or write protected) when
saving files on a vfat partition. MSword calls SetEndOfFile() which
uses ftruncate() that, in Linux, cannot grow files in this filesystem.

BTW. A google search shows that the ftruncate problem has been
mentioned at least 3 times on c.e.m.w. in the last 6 months Since
nobody entered a fix, I could be overlooking something...

Changelog
	server	: file.c
	On the server side of SetEndOfFile, use an alternate method
	to grow a file when ftruncate refuses to do so.
	(eg with vfat filesystem under Linux)

Rein.
-- 
Rein Klazes
rklazes at xs4all.nl
-------------- next part --------------
--- wine/server/file.c	Tue Jan 15 13:24:26 2002
+++ mywine/server/file.c	Sun Jan 20 19:33:08 2002
@@ -456,6 +456,32 @@
     return 1;
 }
 
+/* wrapper around ftruncate:
+ * ftruncate may fail to grow the size of a file with some OS and filesystem
+ * combinations. Linux and vfat/fat is one example. If this is the case do
+ * a write to grow the file to the desired length.
+ */
+static int _ftruncate ( int fd, off_t length)
+{
+    struct stat st;
+    int ret, ret_errno;
+    char buf[1]={'\0'};
+    /* first try with ftruncate */
+    ret = ftruncate( fd, length);
+    if(ret != -1) return ret;
+    ret_errno = errno;
+    if( fstat( fd, &st ) == -1) return -1;
+    if( st.st_size == length ) return 0;
+    errno = ret_errno;
+    /* ftruncate() shouldn't fail when requested to shrink the file */
+    if( st.st_size > length ) return -1;
+    /* file pointer is at the requested size */
+    if( lseek( fd, -1, SEEK_CUR) == -1) return -1;
+    /* write one byte, filepointer is back at the orig. position. */
+    if( write( fd, &buf, 1) == -1) return -1;
+    return 0;
+}
+
 static int truncate_file( handle_t handle )
 {
     struct file *file;
@@ -464,7 +490,7 @@
     if (!(file = get_file_obj( current->process, handle, GENERIC_WRITE )))
         return 0;
     if (((result = lseek( file->obj.fd, 0, SEEK_CUR )) == -1) ||
-        (ftruncate( file->obj.fd, result ) == -1))
+        (_ftruncate( file->obj.fd, result ) == -1))
     {
         file_set_error();
         release_object( file );