msi: If a feature's action is INSTALLSTATE_UNKNOWN, MsiEvaluateCondition should…

dlls/msi/cond.y

@@ -317,7 +317,11 @@ value_i:
             INSTALLSTATE install = INSTALLSTATE_UNKNOWN, action = INSTALLSTATE_UNKNOWN;
       
             MSI_GetFeatureStateW(cond->package, $2, &install, &action );
-            $$ = action;
+            if (action == INSTALLSTATE_UNKNOWN)
+                $$ = MSICONDITION_FALSE;
+            else
+                $$ = action;
+
             msi_free( $2 );
         }
   | COND_EXCLAM identifier

dlls/msi/tests/package.c

@@ -986,6 +986,9 @@ static void test_condition(void)
     r = MsiEvaluateCondition(hpkg, "0");
     ok( r == MSICONDITION_FALSE, "wrong return val\n");
 
+    r = MsiEvaluateCondition(hpkg, "-1");
+    ok( r == MSICONDITION_TRUE, "wrong return val\n");
+
     r = MsiEvaluateCondition(hpkg, "0 = 0");
     ok( r == MSICONDITION_TRUE, "wrong return val\n");
 
@@ -1622,6 +1625,10 @@ static void test_condition(void)
     r = MsiEvaluateCondition(hpkg, "X !=\"\" and (X =\"5.0\" or X =\"5.1\" or X =\"6.0\")");
     ok( r == MSICONDITION_ERROR, "wrong return val (%d)\n", r);
 
+    /* feature doesn't exist */
+    r = MsiEvaluateCondition(hpkg, "&nofeature");
+    ok( r == MSICONDITION_FALSE, "wrong return val (%d)\n", r);
+
     MsiCloseHandle( hpkg );
     DeleteFile(msifile);
 }