Update documentation & add tests as per lastest changes

README.md

@@ -5938,14 +5938,14 @@ However, you can use the break instruction to quit the block (the clear function
 and you can chain the M\_LET macro to create several different variables.
 
 
-##### M\_LET\_IF(init_code, test_code, clear_code)
+##### M\_LET\_IF(init_code, test_code, clear_code [, else_code] )
 
 This macro defines the variable(s) in 'init_code',
 executes the next block of instructions where the variable(s) is(are) used if the initialization succeeds by testing 'test_code',
 then it executes the 'clear_code'.
 
 'test_code' returns a boolean indicating if the initialization succeeds (true) or not.
-If the initialization fails, it won't call the 'clear_code'.
+If the initialization fails, it won't call the 'clear_code', but the 'else_code' if present.
 
 The syntax of 'init_code' is the same as a for loop.
 

tests/test-mcore.c

@@ -206,6 +206,15 @@ static void test_let(void)
     *p = 4;
   }
 
+  M_LET_IF( assert(c++ == 7), (assert(c++ == 8), true), assert(c++ == 10), assert(0) ) {
+    assert(c++ == 9);
+  }
+  M_LET_IF( assert(c++ == 11), (assert(c++ == 12), false), assert(0), assert(c++ == 13) ) {
+    assert(0);
+  }
+  assert(c++ == 14);
+
+  c = 7;
   int *p = (int*)malloc(sizeof(int));
   assert(p != NULL);
   M_DEFER ( (assert(c++ == 8), free(p)) ) {