Merge pull request #762 from Varriount/os/fix-removeFile2

Fix os.removeFile behavior on windows (again)

lib/pure/os.nim

@@ -970,15 +970,35 @@ proc moveFile*(source, dest: string) {.rtl, extern: "nos$1",
   if crename(source, dest) != 0'i32:
     raise newException(EOS, $strerror(errno))
 
-when not defined(ENOENT):
+when not defined(ENOENT) and not defined(Windows):
   var ENOENT {.importc, header: "<errno.h>".}: cint
 
+when defined(Windows):
+  when useWinUnicode:
+    template DeleteFile(file: expr): expr {.immediate.} = DeleteFileW(file)
+    template SetFileAttributes(file, attrs: expr): expr {.immediate.} = 
+      SetFileAttributesW(file, attrs)
+  else:
+    template DeleteFile(file: expr): expr {.immediate.} = DeleteFileA(file)
+    template SetFileAttributes(file, attrs: expr): expr {.immediate.} = 
+      SetFileAttributesA(file, attrs)
+
 proc removeFile*(file: string) {.rtl, extern: "nos$1", tags: [FWriteDir].} =
   ## Removes the `file`. If this fails, `EOS` is raised. This does not fail
   ## if the file never existed in the first place.
   ## On Windows, ignores the read-only attribute.
   when defined(Windows):
-    setFilePermissions(file, {fpUserWrite})
+    when useWinUnicode:
+      let f = newWideCString(file)
+    else:
+      let f = file
+    if DeleteFile(f) == 0:
+      if GetLastError() == ERROR_ACCESS_DENIED: 
+        if SetFileAttributes(f, FILE_ATTRIBUTE_NORMAL) == 0:
+          OSError(OSLastError())
+        if DeleteFile(f) == 0:
+          OSError(OSLastError())
+  else:
     if cremove(file) != 0'i32 and errno != ENOENT:
       raise newException(EOS, $strerror(errno))
 

lib/windows/winlean.nim

@@ -553,18 +553,26 @@ const
 
   FILE_FLAG_BACKUP_SEMANTICS* = 33554432'i32
 
+# Error Constants
+const
+  ERROR_ACCESS_DENIED* = 5
+
 when useWinUnicode:
   proc CreateFileW*(lpFileName: widecstring, dwDesiredAccess, dwShareMode: DWORD,
                     lpSecurityAttributes: pointer,
                     dwCreationDisposition, dwFlagsAndAttributes: DWORD,
                     hTemplateFile: THANDLE): THANDLE {.
       stdcall, dynlib: "kernel32", importc: "CreateFileW".}
+  proc DeleteFileW*(pathName: widecstring): int32 {.
+    importc: "DeleteFileW", dynlib: "kernel32", stdcall.}
 else:
   proc CreateFileA*(lpFileName: cstring, dwDesiredAccess, dwShareMode: DWORD,
                     lpSecurityAttributes: pointer,
                     dwCreationDisposition, dwFlagsAndAttributes: DWORD,
                     hTemplateFile: THANDLE): THANDLE {.
       stdcall, dynlib: "kernel32", importc: "CreateFileA".}
+  proc DeleteFileA*(pathName: cstring): int32 {.
+    importc: "DeleteFileA", dynlib: "kernel32", stdcall.}
 
 proc SetEndOfFile*(hFile: THANDLE): WINBOOL {.stdcall, dynlib: "kernel32",
     importc: "SetEndOfFile".}