cmd: for /f fails to launch quoted program plus args.

for /f can run a program and parse its output. The program name can
supply args and be quoted or not.  If quoted, wine fails to run the
program because internally we were adding an extra pair of
quotes. These are not needed and can be removed.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=39906
Signed-off-by: Jason Edmeades <us@edmeades.me.uk>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

programs/cmd/builtins.c

@@ -2073,7 +2073,7 @@ static HANDLE WCMD_forf_getinputhandle(BOOL usebackq, WCHAR *itemstr, BOOL iscmd
   static const WCHAR redirOutW[]  = {'>','%','s','\0'};
   static const WCHAR cmdW[]       = {'C','M','D','\0'};
   static const WCHAR cmdslashcW[] = {'C','M','D','.','E','X','E',' ',
-                                     '/','C',' ','"','%','s','"','\0'};
+                                     '/','C',' ','%','s','\0'};
 
   /* Remove leading and trailing character */
   if ((iscmd && (itemstr[0] == '`' && usebackq)) ||

programs/cmd/tests/test_builtins.cmd

@@ -1724,9 +1724,11 @@ if "%CD%"=="" goto :SkipFORFcmdNT4
 for /f %%i in ('echo.Passed1') do echo %%i
 for /f "usebackq" %%i in (`echo.Passed2`) do echo %%i
 for /f usebackq %%i in (`echo.Passed3`) do echo %%i
+for /f "usebackq" %%i in (`"c:\windows\system32\cmd.exe" /C echo Passed4`) do echo %%i
+for /f "usebackq" %%i in (`""c:\windows\system32\cmd.exe" /C echo Passed5"`) do echo %%i
 goto :ContinueFORF
 :SkipFORFcmdNT4
-for /l %%i in (1,1,3) do echo Missing functionality - Broken%%i
+for /l %%i in (1,1,5) do echo Missing functionality - Broken%%i
 :ContinueFORF
 rem FIXME: Rest not testable right now in wine: not implemented and would need
 rem preliminary grep-like program implementation (e.g. like findstr or fc) even

programs/cmd/tests/test_builtins.cmd.exp

@@ -1209,6 +1209,8 @@ c
 Passed1@or_broken@Missing functionality - Broken1
 Passed2@or_broken@Missing functionality - Broken2
 Passed3@or_broken@Missing functionality - Broken3
+Passed4@or_broken@Missing functionality - Broken4
+Passed5@or_broken@Missing functionality - Broken5
 ------ eol option
 and@or_broken@Broken NT4 functionality1
 Line@or_broken@Broken NT4 functionality2