Hi Hannes,

On Mon, 2 Dec 2019, Johannes Sixt wrote:

Am 02.12.19 um 12:33 schrieb Johannes Schindelin via GitGitGadget:

quoted

Range-diff vs v2:

 1:  280b6d08a4 = 1:  280b6d08a4 mingw: do set `errno` correctly when trying to restrict handle inheritance
 2:  c3dea00fb1 ! 2:  e04e1269b3 mingw: translate ERROR_SUCCESS to errno = 0
     @@ -3,12 +3,15 @@
          mingw: translate ERROR_SUCCESS to errno = 0

The subject line would have to be adjusted as well.

	mingw: forbid translating ERROR_SUCCESS to an errno value

or something.

Oy. Thank you for catching this! (It is always amazing to me how much I
miss when I have stared at the same commits for a while.)

For good measure, I force-pushed the branch of the PR to match what Junio
has in `pu`, but if there are no other changes I need to make, I will
refrain from submitting another iteration.

Thanks,
Dscho

quoted

          Johannes Sixt pointed out that the `err_win_to_posix()` function
     -    mishandles `ERROR_SUCCESS`. This commit fixes that.
     +    mishandles `ERROR_SUCCESS`: it maps it to `ENOSYS`.

     -    Technically, we try to only assign `errno` to the corresponding value of
     -    `GetLastError()` (which translation is performed by that function) when
     -    a Win32 API call failed, so this change is purely defensive and is not
     -    expected to fix an existing bug in our code base.
     +    The only purpose of this function is to map Win32 API errors to `errno`
     +    ones, and there is actually no equivalent to `ERROR_SUCCESS`: the idea
     +    of `errno` is that it will only be set in case of an error, and left
     +    alone in case of success.
     +
     +    Therefore, as pointed out by Junio Hamano, it is a bug to call this
     +    function when there was not even any error to map.

          Signed-off-by: Johannes Schindelin [off-list ref]

     @@ -19,7 +22,7 @@
       	case ERROR_SHARING_BUFFER_EXCEEDED: error = ENFILE; break;
       	case ERROR_SHARING_VIOLATION: error = EACCES; break;
       	case ERROR_STACK_OVERFLOW: error = ENOMEM; break;
     -+	case ERROR_SUCCESS: error = 0; break;
     ++	case ERROR_SUCCESS: BUG("err_win_to_posix() called without an error!");
       	case ERROR_SWAPERROR: error = ENOENT; break;
       	case ERROR_TOO_MANY_MODULES: error = EMFILE; break;
       	case ERROR_TOO_MANY_OPEN_FILES: error = EMFILE; break;

-- Hannes