cmd: Fix 'if exist' with a directory\ as a parameter.

programs/cmd/builtins.c

@@ -2861,7 +2861,14 @@ void WCMD_if (WCHAR *p, CMD_LIST **cmdList)
   }
   else if (!lstrcmpiW (condition, existW)) {
     WIN32_FIND_DATAW fd;
-    HANDLE hff = FindFirstFileW(WCMD_parameter(p, 1+negate, NULL, FALSE, FALSE), &fd);
+    HANDLE hff;
+    WCHAR *param = WCMD_parameter(p, 1+negate, NULL, FALSE, FALSE);
+    int    len = strlenW(param);
+
+    /* FindFirstFile does not like a directory path ending in '\', append a '.' */
+    if (len && param[len-1] == '\\') strcatW(param, dotW);
+
+    hff = FindFirstFileW(param, &fd);
     test = (hff != INVALID_HANDLE_VALUE );
     if (test) FindClose(hff);
 

programs/cmd/tests/test_builtins.cmd

@@ -1046,6 +1046,26 @@ if exist idontexist\ba* (
 ) else (
    echo exist wildcard bad subdir broken works
 )
+if exist subdir (
+   echo exist subdir ok
+) else (
+   echo ERROR exist subdir not working
+)
+if exist subdir\. (
+   echo exist subdir with . ok
+) else (
+   echo ERROR exist subdir with . not working
+)
+if exist subdir\ (
+   echo exist subdir with \ ok
+) else (
+   echo ERROR exist subdir with \ not working
+)
+if exist "subdir\" (
+   echo exist subdir with \ and quotes ok
+) else (
+   echo ERROR exist subdir with \ and quotes not working
+)
 del foo subdir\bar
 rd subdir
 

programs/cmd/tests/test_builtins.cmd.exp

@@ -783,6 +783,10 @@ exist simple wildcard works
 exist wildcard works
 negate exist wildcard works
 exist wildcard bad subdir broken works
+exist subdir ok
+exist subdir with . ok
+exist subdir with \ ok
+exist subdir with \ and quotes ok
 ------ for numbers
 negative numbers handled
 negative numbers handled