read_key(): placate "warning: shifting a negative signed value is undefined"

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/libbb/read_key.c b/libbb/read_key.c
index 951786869c25e8104ca84bd4abfd4cf495539790..03b7da65651522b99619246f4757a96f77481953 100644 (file)
--- a/libbb/read_key.c
+++ b/libbb/read_key.c
@@ -259,7 +259,8 @@ int64_t FAST_FUNC read_key(int fd, char *buffer, int timeout)
 
                        buffer[-1] = 0;
                        /* Pack into "1 <row15bits> <col16bits>" 32-bit sequence */
-                       col |= (((-1 << 15) | row) << 16);
+                       row |= ((unsigned)(-1) << 15);
+                       col |= (row << 16);
                        /* Return it in high-order word */
                        return ((int64_t) col << 32) | (uint32_t)KEYCODE_CURSOR_POS;
                }