Re: Small issue with lfs compiled under mingw

[Lorenzo Donati <lorenzodonatibz@...>]

On 28/07/2011 0.00, Lorenzo Donati wrote:
> Hi all!
>
> Some time ago I compiled lfs using mingw "by hand" (the distro came with
> a makefile for VC only, so I concocted one) and put lfs.dll in my cpath
> for using other libraries that required it - never had problems with it.
>
> Lately I'm cleaning-up my (ugly) makefiles and I rewrote the one for
> building lfs, enabling more warnings and performing the test script.
> Now I have some issues:
>
> 1. compiling lfs.c gives some warnings.
> 2. running test.lua fails with an assertion.

Probably I've tracked down the problem [2] and found a solution, but I'd 
like to have a feedback from more expert C folks.

First a test that fails on my system:


----------------------------------------
lfs = require 'lfs'
-- "mydir" is an existing dir with two files "a" and "b" in it.
iter, dir = assert( lfs.dir( dirname ) )
dir:close()
print( dir:next() or "<no ret val>" )  --> .
print( dir:next() or "<no ret val>" )  --> ..
print( dir:next() or "<no ret val>" )  --> a
print( dir:next() or "<no ret val>" )  --> b
print( dir:next() or "<no ret val>" )  --> <no ret val>
print( dir:next() or "<no ret val>" )  -- *** ERROR! ***
----------------------------------------

That is, the dir object can be used for iteration although it has been 
closed just after creation.

Let's try with this one:

----------------------------------------
lfs = require 'lfs'
iter, dir = assert( lfs.dir( dirname ) )
print( dir:next() or "<no ret val>" )  --> .
dir:close()
print( dir:next() or "<no ret val>" )  -- *** ERROR! ***
----------------------------------------
That is, the dir object is actually invalidated as expected.

Therefore it seems that for dir:close to work it is necessary to call 
dir:next at least once, which is weird.

Analyzing the source I found a possible solution (patch attached), but I 
don't know if it could break something else.

With that patch applied the test.lua file of lfs distro passes without 
raising any assertion.

Any comment appreciated.

TIA
-- Lorenzo

diff --git b/src/lfs.c a/src/lfs.c
index f46cfed..18255a2 100644
--- b/src/lfs.c
+++ a/src/lfs.c
@@ -455,8 +455,9 @@ static int dir_iter (lua_State *L) {
 static int dir_close (lua_State *L) {
 	dir_data *d = (dir_data *)lua_touserdata (L, 1);
 #ifdef _WIN32
-	if (!d->closed && d->hFile) {
-		_findclose (d->hFile);
+	if (!d->closed ) {
+		if( d->hFile )
+			_findclose (d->hFile);
 		d->closed = 1;
 	}
 #else