(SINGLE_BYTE_CHAR_P): Check if C is negative or not.

diff --git a/src/charset.h b/src/charset.h
index 957cb4afdb9d6207abcb27ccc0c94358bc236c26..44955fa3ac4f2fb6bb6d876b212a8d00364a029a 100644 (file)
--- a/src/charset.h
+++ b/src/charset.h
@@ -250,7 +250,7 @@ extern int charset_big5_2;  /* Big5 Level 2 (Chinese Traditional) */
 #define GENERIC_COMPOSITION_CHAR (GLYPH_MASK_CHAR)
 
 /* 1 if C is an ASCII character, else 0.  */
-#define SINGLE_BYTE_CHAR_P(c) ((c) < 0x100)
+#define SINGLE_BYTE_CHAR_P(c) ((c) >= 0 && (c) < 0x100)
 /* 1 if C is an composite character, else 0.  */
 #define COMPOSITE_CHAR_P(c) ((c) >= MIN_CHAR_COMPOSITION)