scc

commit 665b4e3615c9340253803722761e83a70ffefa7c
parent f75308d46c6b043f5b284fae0e149352f01f839c
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Tue,  5 Dec 2017 20:48:09 +0100

[lib/c] Fix number conversions with prefix

When we want to prefix with 0 a number we have to worry about the
prefix of the number, because if it begins with a sign or 0x then
we have to append the 0 after the prefix.

Diffstat:
M
lib/c/src/vfprintf.c
 | 
22
++++++++++++++++------

1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/lib/c/src/vfprintf.c b/lib/c/src/vfprintf.c
@@ -80,6 +80,7 @@ numtostr(uintmax_t val, int flags, struct conv *conv, char *buf)
 {
 	char *buf0 = buf;
 	int len, base = conv->base, prec = conv->prec;
+	uintmax_t oval = val;
 
 	if (prec == -1)
 		prec = 1;
@@ -89,14 +90,10 @@ numtostr(uintmax_t val, int flags, struct conv *conv, char *buf)
 	while (buf0 - buf < prec)
 		*--buf = '0';
 
-	/*
-	 * TODO: It cannot be done here because the combination
-	 * %#04x produces 00x1
-	 */
 	if (flags & ALTFORM) {
 		if (base == 8 && *buf != '0') {
 			*--buf = '0';
-		} else if (base == 16 && val != 0) {
+		} else if (base == 16 && oval != 0) {
 			*--buf = conv->digs[16];
 			*--buf = '0';
 		}
@@ -161,7 +158,7 @@ wstrout(wchar_t *ws, size_t len, int width, int fill, FILE * restrict fp)
 static size_t
 strout(char *s, size_t len, int width, int fill, FILE * restrict fp)
 {
-	int left = 0, adjust, ch;
+	int left = 0, adjust, ch, prefix;
 	size_t cnt = 0;
 
 	if (width < 0) {
@@ -176,6 +173,19 @@ strout(char *s, size_t len, int width, int fill, FILE * restrict fp)
 	if (left)
 		adjust = -adjust;
 
+	if (fill == '0') {
+		if (*s == '-' || *s == '+')
+			prefix = 1;
+		else if (*s == '0' && toupper(s[1]) == 'X')
+			prefix = 2;
+		else
+			prefix = 0;
+		while (prefix--) {
+			putc(*s++, fp);
+			--len;
+		}
+	}
+
 	for ( ; adjust > 0; adjust--)
 		putc(fill, fp);