several bug fixes after test-suite

lang/cem/libcc.ansi/stdlib/ext_comp.c

@@ -501,6 +501,7 @@ _str_ext_cvt(char *s, char **ss, struct EXTEND *e)
 	if (c == 'E' || c == 'e') {
 		int	exp1 = 0;
 		int	sign = 1;
+		int	exp_overflow = 0;
 
 		switch(*s) {
 		case '-':
@@ -515,13 +516,16 @@ _str_ext_cvt(char *s, char **ss, struct EXTEND *e)
 				exp1 = 10 * exp1 + (c - '0');
 				if ((tmp = sign * exp1 + exp) > MAX_EXP ||
 				     tmp < -MAX_EXP) {
-					errno = ERANGE;
+					exp_overflow = 1;
 				}
 			} while (c = *++s, isdigit(c));
 			if (ss) *ss = s;
 		}
 		exp += sign * exp1;
-		if (errno == ERANGE) exp = sign * MAX_EXP;
+		if (exp_overflow) {
+			exp = sign * MAX_EXP;
+			if (e->m1 != 0 || e->m2 != 0) errno = ERANGE;
+		}
 	}
 	if (e->m1 == 0 && e->m2 == 0) return;
 	e->exp = 63;

lang/cem/libcc.ansi/stdlib/mbtowc.c

@@ -11,7 +11,6 @@ int
 mbtowc(wchar_t *pwc, register const char *s, size_t n)
 {
 	if (s == (const char *)NULL) return 0;
-	if (*s == '\0') return 0;
 	if (n <= 0) return 0;
 	if (pwc) *pwc = *s;
 	return (*s != 0);

lang/cem/libcc.ansi/stdlib/strtol.c

@@ -74,14 +74,13 @@ string2long(register const char *nptr, char ** const endptr,
 		else *endptr = (char *)nptr;
 	}
 
-	/* We can't represent a negative unsigned long, nor a long that
-	 * is smaller than LONG_MIN or larger than LONG_MAX.
-	 */
 	if (!ovfl) {
-		if (!is_signed)
-			if (sign < 0 && val != 0)
-				ovfl++;
-			else if (((sign < 0 && val > -LONG_MIN)
+		/* Overflow is only possible when converting a signed long.
+		 * val is unsigned long, so -LONG_MIN is converted to
+		 * unsigned long.
+		 */
+		if (is_signed
+		    && (   (sign < 0 && val > -LONG_MIN)
 			|| (sign > 0 && val > LONG_MAX)))
 		    ovfl++;
 	}
@@ -93,6 +92,5 @@ string2long(register const char *nptr, char ** const endptr,
 			else return LONG_MAX;
 		else return ULONG_MAX;
 	}
-	if (is_signed)	return (unsigned long) sign * val;
-	else return val;
+	return (unsigned long) sign * val;
 }

lang/cem/libcc.ansi/stdlib/wcstombs.c

@@ -14,8 +14,8 @@ wcstombs(register char *s, register const wchar_t *pwcs, size_t n)
 	register int i = n;
 
 	while (--i >= 0) {
-		if (!(*s++ = *pwcs))
-			return n - i - 1;
+		if (!(*s++ = *pwcs++))
+			break;
 	}
-	return n - i;
+	return n - i - 1;
 }

lang/cem/libcc.ansi/stdlib/wctomb.c

@@ -13,5 +13,5 @@ wctomb(char *s, wchar_t wchar)
 	if (!s) return 0;		/* no state dependent codings */
 
 	*s = wchar;
-	return (wchar != 0);
+	return (*s != '\0');
 }