fix build regression on archs with variable page size

[musl] / src / internal / stdio_impl.h

diff --git a/src/internal/stdio_impl.h b/src/internal/stdio_impl.h
index 0dd7fb5..7cdf729 100644 (file)
--- a/src/internal/stdio_impl.h
+++ b/src/internal/stdio_impl.h
@@ -86,7 +86,8 @@ void __ofl_unlock(void);
 #define getc_unlocked(f) \
        ( ((f)->rpos < (f)->rend) ? *(f)->rpos++ : __uflow((f)) )
 
-#define putc_unlocked(c, f) ( ((c)!=(f)->lbf && (f)->wpos<(f)->wend) \
+#define putc_unlocked(c, f) \
+       ( ((unsigned char)(c)!=(f)->lbf && (f)->wpos<(f)->wend) \
        ? *(f)->wpos++ = (c) : __overflow((f),(c)) )
 
 /* Caller-allocated FILE * operations */