Fix shift UB in mbfilter_utf32.c

diff --git a/ext/mbstring/libmbfl/filters/mbfilter_utf32.c b/ext/mbstring/libmbfl/filters/mbfilter_utf32.c
index 5b02362b5d11f500aedb732775cb7414101026c4..b1b41331eb69ed138f814f95d038e6209792a024 100644 (file)
--- a/ext/mbstring/libmbfl/filters/mbfilter_utf32.c
+++ b/ext/mbstring/libmbfl/filters/mbfilter_utf32.c
@@ -138,7 +138,7 @@ int mbfl_filt_conv_utf32_wchar(int c, mbfl_convert_filter *filter)
                if (endian) {
                        n = c & 0xff;
                } else {
-                       n = (c & 0xff) << 24;
+                       n = (unsigned) (c & 0xff) << 24;
                }
                filter->cache = n;
                filter->status++;