From a2a4e419752d5c50a3879019145caa0b91042941 Mon Sep 17 00:00:00 2001
From: tg <tg@mirbsd.org>
Date: Sun, 19 Apr 2015 18:13:31 +0000
Subject: [PATCH] make var.c:getint() more like misc.c:getn(), except for the
 API differences: getn() parses a decimal 32-bit integer, getint() a POSIX- or
 ksh-style based integer with unsigned wraparound to 32 bit, then possible
 negation (so that, for example, -0xFFFFFFFF continues to work)

---
 var.c | 75 +++++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 47 insertions(+), 28 deletions(-)

diff --git a/var.c b/var.c
index caebb0e..0b2990f 100644
--- a/var.c
+++ b/var.c
@@ -28,7 +28,7 @@
 #include <sys/sysctl.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/var.c,v 1.188 2015/04/19 14:22:09 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/var.c,v 1.189 2015/04/19 18:13:31 tg Exp $");
 
 /*-
  * Variables
@@ -481,41 +481,57 @@ setint(struct tbl *vq, mksh_ari_t n)
 static int
 getint(struct tbl *vp, mksh_ari_u *nump, bool arith)
 {
-	mksh_uari_t c, num, base;
+	mksh_uari_t c, num = 0, base = 10;
 	const char *s;
 	bool have_base = false, neg = false;
 
-	if (vp->flag&SPECIAL)
+	if (vp->flag & SPECIAL)
 		getspec(vp);
 	/* XXX is it possible for ISSET to be set and val.s to be NULL? */
-	if (!(vp->flag&ISSET) || (!(vp->flag&INTEGER) && vp->val.s == NULL))
+	if (!(vp->flag & ISSET) || (!(vp->flag & INTEGER) && vp->val.s == NULL))
 		return (-1);
-	if (vp->flag&INTEGER) {
+	if (vp->flag & INTEGER) {
 		nump->i = vp->val.i;
 		return (vp->type);
 	}
 	s = vp->val.s + vp->type;
-	base = 10;
-	num = 0;
-	if (arith && s[0] == '0' && (s[1] | 0x20) == 'x') {
-		s += 2;
-		base = 16;
-		have_base = true;
+
+	do {
+		c = (unsigned char)*s++;
+	} while (ksh_isspace(c));
+
+	switch (c) {
+	case '-':
+		neg = true;
+		/* FALLTHROUGH */
+	case '+':
+		c = (unsigned char)*s++;
+		break;
 	}
-	if (Flag(FPOSIX) && arith && s[0] == '0' && ksh_isdigit(s[1]) &&
-	    !(vp->flag & ZEROFIL)) {
-		/* interpret as octal (deprecated) */
-		base = 8;
-		have_base = true;
+
+	if (c == '0' && arith) {
+		if ((s[0] | 0x20) == 'x') {
+			/* interpret as hexadecimal */
+			base = 16;
+			++s;
+			goto getint_c_style_base;
+		} else if (Flag(FPOSIX) && ksh_isdigit(s[0]) &&
+		    !(vp->flag & ZEROFIL)) {
+			/* interpret as octal (deprecated) */
+			base = 8;
+ getint_c_style_base:
+			have_base = true;
+			c = (unsigned char)*s++;
+		}
 	}
-	while ((c = (unsigned char)*s++)) {
-		if (c == '-') {
-			neg = true;
-			continue;
-		} else if (c == '#') {
+
+	do {
+		if (c == '#') {
+			/* ksh-style base determination */
 			if (have_base || num < 1)
 				return (-1);
 			if ((base = num) == 1) {
+				/* mksh-specific extension */
 				unsigned int wc;
 
 				if (!UTFMODE)
@@ -535,18 +551,21 @@ getint(struct tbl *vp, mksh_ari_u *nump, bool arith)
 			num = 0;
 			have_base = true;
 			continue;
-		} else if (ksh_isdigit(c))
+		}
+		if (ksh_isdigit(c))
 			c -= '0';
-		else if (ksh_islower(c))
+		else {
+			c |= 0x20;
+			if (!ksh_islower(c))
+				return (-1);
 			c -= 'a' - 10;
-		else if (ksh_isupper(c))
-			c -= 'A' - 10;
-		else
-			return (-1);
+		}
 		if (c >= base)
 			return (-1);
+		/* handle overflow as truncation */
 		num = num * base + c;
-	}
+	} while ((c = (unsigned char)*s++));
+
 	if (neg)
 		num = -num;
 	nump->u = num;