[Vm-dev] [commit][3478] Apply http://forum.world.st/ Patch-FilePlugin-for-Windows-can-now-delete-read-only-files-td4855947. html#a4856703

[commits at squeakvm.org]

Revision: 3478
Author:   eliot
Date:     2015-10-20 15:39:11 -0700 (Tue, 20 Oct 2015)
Log Message:
-----------
Apply http://forum.world.st/Patch-FilePlugin-for-Windows-can-now-delete-read-only-files-td4855947.html#a4856703

Modified Paths:
--------------
    trunk/platforms/win32/plugins/FilePlugin/sqWin32FilePrims.c

Modified: trunk/platforms/win32/plugins/FilePlugin/sqWin32FilePrims.c
===================================================================
--- trunk/platforms/win32/plugins/FilePlugin/sqWin32FilePrims.c	2015-10-20 00:51:42 UTC (rev 3477)
+++ trunk/platforms/win32/plugins/FilePlugin/sqWin32FilePrims.c	2015-10-20 22:39:11 UTC (rev 3478)
@@ -17,6 +17,10 @@
 *   UPDATES:
 *     1) Support for long path names added by using UNC prefix in that case
 *        (Marcel Taeumel, Hasso Plattner Institute, Postdam, Germany)
+*     2) Try to remove the read-only attribute from a file before calling
+*        DeleteFile. DeleteFile cannot delete read-only files (see comment
+*        in sqFileDeleteNameSize).
+*        (Max Leske)
 *
 *****************************************************************************/
 #include <windows.h>
@@ -118,6 +122,20 @@
 
   if(hasCaseSensitiveDuplicate(win32Path))
     FAIL();
+
+  /* DeleteFile will not delete a file with the read-only attribute set
+  (e.g. -r--r--r--, see https://msdn.microsoft.com/en-us/library/windows/desktop/aa363915(v=vs.85).aspx).
+  To ensure that this works the same way as on *nix platforms we need to
+  remove the read-only attribute (which might fail if the current user
+  doesn't own the file).
+    Also note that DeleteFile cannot *effectively* delete a file as long as
+  there are other processes that hold open handles to that file. The function
+  will still report success since the file is *marked* for deletion (no new
+  handles can be opened. See the URL mentioned above for reference).
+  This will lead to problems during a recursive delete operation since now
+  the parent directory wont be empty. */
+  SetFileAttributesW(win32Path, FILE_ATTRIBUTE_NORMAL);
+
   if(!DeleteFileW(win32Path))
     FAIL();
   
@@ -302,7 +320,7 @@
    * sqFileFlush uses FlushFileBuffers which is equivalent to fsync on windows
    * as long as WriteFile is used directly and no other buffering is done.
    */
-  return sqFileFlush(SQFile *f);
+  return sqFileFlush(f);
 }
 
 sqInt sqFileTruncate(SQFile *f, squeakFileOffsetType offset) {