ext/standard/crypt.c: handle musl failure tokens

Musl's crypt() returns "*" to indicate failure in contrast with the
"*0" returned by PHP/libxcrypt. This causes test failures, but more
importantly, is a pretty silly thing to expect the user to know.
This commit catches the musl value and turns it into "*0".

Author: orlitzky

ext/standard/crypt.c

@@ -215,6 +215,17 @@ PHP_FUNCTION(crypt)
 			RETURN_STRING("*0");
 		}
 	}
+	else if (zend_string_equals_literal(result, "*")) {
+		/* Musl crypt() uses "*" as a failure token rather
+		 * than the "*0" that libxcrypt/PHP use. Our test
+		 * suite in particular looks for "*0" in a few places,
+		 * and it would be annoying to handle both values
+		 * explicitly. It seems wise to abstract this detail
+		 * from the end user: if it's annoying for us, imagine
+		 * how annoying it would be in end-user code; not that
+		 * anyone would think of it. */
+		RETURN_STRING("*0");
+	}
 	RETURN_STR(result);
 }
 /* }}} */