expr: fix erroneous comparison

as long as `size_t`'s conversion rank is >= `int` this check would work
out fine.

but in case size_t happens to be less than int (which I believe is valid
under the C standard) then comparison will take place in `signed int`
and the operand `-1` will not get implicitly converted to SIZE_MAX.

explicitly cast it to size_t to avoid such issues.

1 files changed, 1 insertions, 1 deletions

diff --git a/expr.c b/expr.c
index dc11aec..83e80f7 100644
--- a/expr.c
+++ b/expr.c
@@ -403,7 +403,7 @@ decodechar(const char *src, uint_least32_t *chr, bool *hexoct, const char *desc,
 		}
 	} else {
 		n = utf8dec(&c, s, 4);
-		if (n == -1)
+		if (n == (size_t)-1)
 			error(loc, "%s contains invalid UTF-8", desc);
 		s += n;
 	}